Best Milk Thistle Supplement

If you’re one of the 57.6% of Americans over 20 who take a dietary supplement,62 then you may be all too familiar with how complicated a regimen can get. Many of us have dedicated kitchen or bathroom shelves lined with assorted jars, bottles, and blister packs, each corresponding to a specific need. So when you come across a product that can serve multiple purposes — a so-called “holy grail” supplement — it can come as a relief.

One such supplement is milk thistle. Ancient Greeks regarded it as a general medicinal herb as far back as the fourth century BCE.1 Recently, it has been gaining popularity for its potential to support liver health, diabetes, cancer, lactation, and more.

In this guide, we examine whether milk thistle truly has a claim to be a holy grail supplement and which brands are most worth your attention.

Take a glance at our summary of recommendations for a quick rundown, and read further to understand how we came to rate the best of the bunch.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions involving staying healthy and living healthier lifestyles.

For every review and guide we write, we dedicate dozens, sometimes hundreds, of hours to locating, analyzing, and summarizing the most reliable sources. As a subject, milk thistle was no different. We referenced more than 60 scientific sources across 60+ hours so that we could distill the most salient information on milk thistle into an easily digestible guide on its use as a supplement. We also purchased and tried the market's leading milk thistle supplements so we could speak authoritatively about the customer experience, particularly with regard to purchasing, support, delivery, and use.

Additionally, like all health-related content on this website, this guide was thoroughly vetted by one or more members of our Medical Review Board for accuracy.

We’ll continue to monitor the milk thistle space in the years to come, familiarizing ourselves with new products and changes to existing supplements so that our recommendations are up-to-date.

In rating the market's best milk thistle supplements, we were primarily concerned that the doses used lined up with effective clinical ranges without putting your health at risk, and we looked into each brand’s safety standards so you can be sure of getting a healthful product. Hence, efficacy and safety were our foremost evaluative factors. After that, we turned our eyes to the cost and convenience of each supplement — criteria that are likely to inform your purchase decisions. Here's how our top recommendations stacked up in each category.

Efficacy

Winner: Life Extension Advanced Milk Thistle

Our evaluations of efficacy concerned how likely a given supplement is to provide the antioxidant and anti-fibrotic (i.e., anti-scarring of tissues and organs) health benefits for which milk thistle is known. To understand the logic behind our choice, you need to know three key points:

• The chief active ingredient in milk thistle is a flavonoid complex called silymarin.
• Studies show that silymarin can be effective at doses of 200-600mg per day for most users.2
• Silymarin is lipophilic and hydrophobic, meaning that it has an affinity for fats and is largely insoluble in water. Only around 20-50% of it gets absorbed into the body.3

Therefore, the efficacy of a milk thistle supplement depends on its dosage and its ability to maximize the amount of silymarin it passes through your gastrointestinal tract. Almost all of our top milk thistle recommendations deliver sufficient amounts of standardized silymarin, but only one bolsters its formulation with a mechanism for maximizing bioavailability: Life Extension Advanced Milk Thistle. Its regular formulation consists of:

• Milk Thistle Phospholipid Proprietary Blend: milk thistle integrated into a phospholipid complex, which bridges silymarin’s lipophilia and hydrophobia to improve absorption and bioavailability4
• Siliphos: a branded milk thistle phytosome, which research suggests is better at moving into cells and reaching the bloodstream5

About Siliphos — in Life Extension, the phosphates are carriers of silybin, believed to be the primary compound responsible for milk thistle's biological activity, particularly with regard to liver health.6 Here, the Siliphos provides 47.52mg of additional silybin, so the key takeaway (again) is that Life Extension delivers increased bioavailability of an important active compound. (Of note, Life Extension is the only one of our milk thistle recommendations that specifies silybin content.) What’s more, the company that makes Siliphos, Indena, has conducted a handful of studies on it, which we cover in greater detail down in Life Extension’s dedicated section.

By the way, you'll notice that Life Extension uses a proprietary blend. Often, "proprietary blend" is synonymous with "hidden quantities," but that isn't the case here (unlike Legendairy Milk’s Liquid Gold). On the label, Life Extension lists not only the overall dosage of its phospholipid formula but also the individual dosage of each constituent ingredient — 480mg silymarin (within the effective dose range),2 180mg silybin, and 48mg isosilybin A/B. Its silymarin content is lower compared to NOW Foods and HUM Nutrition, but given the higher bioavailability afforded by the phospholipid mechanism, you stand to get more silymarin per dose than with those competitors.

NOW Foods and HUM Nutrition deserve some nods for efficacy, too. Their respective 750mg and 600mg silymarin doses are high enough that your body could absorb enough to realize the associated health benefits. At the lowest end of potential absorption from milk thistle supplements (20%), you’d be getting 150mg from NOW and 120mg from HUM; at the highest (50%), you’d absorb 375mg and 300mg, respectively.3

The silymarin quantities of our other recommended brands, Nootropics Depot and Legendairy Milk, are either lower or unspecified, but they include other ingredients that have the potential to help with other concerns. For example, Nootropics Depot’s berberine formulation has utility for diabetes control,45 while the galactagogue blend in Legendairy Milk’s Liquid Gold can boost lactation. We cover those applications in later sections.

Safety

Winner: Life Extension Advanced Milk Thistle

Categorically, milk thistle is neither a food nor a medicine; it's a type of dietary supplement, which places it outside the purview of FDA approval (the standard for safety and effectiveness in the United States).7 Therefore, to evaluate supplement safety, we have to examine other key criteria, namely manufacturing practices and third-party testing.

Life Extension Advanced Milk Thistle is our safety winner because of the rigorous standards set by the company. Life Extension maintains the following:

Of course, we'd be remiss if we didn't mention NOW Foods, whose safety procedures are impressive enough that we consider its Milk Thistle Extract Maximum Strength as the runner-up for safety. Like Life Extension, the company is certified to adhere to GMP standards, and its Maximum Strength milk thistle holds three certifications verifying different levels of safety or safe consumption — Intertek GMP Supplement Certification, Non-GMO, and Vegan. Moreover, NOW Foods has in-house labs that are accredited by the ISO, a mark of quality assurance. So, why runner-up and not first place? We feel that NSF certification and third-party testing speak to greater objectivity in safety analysis, and NOW Foods' milk thistle has no association with either distinction.

As for the other brands in our guide, most of them do take commendable safety measures. HUM Nutrition and Nootropics Depot are both GMP-compliant and use third-party testers (the latter in a self-owned facility audited and accredited by an independent third party, Perry Johnson Laboratories), but neither one is NSF-certified. For Legendairy Milk, we can at least say its products are made in a GMP-compliant facility, and its Liquid Gold supplement is certified USDA organic, vegan, non-GMO, kosher, and halal.

Keep in mind, a few of these milk thistle supplements contain additional ingredients that may pose some degree of risk to certain users. For example, some people may be allergic to the artichoke used in HUM’s Wing Man or the soy in Life Extension’s Advanced Milk Thistle. You can find details on these risky ingredients under each supplement’s dedicated section.

Cost

Winner: NOW Foods Milk Thistle Extract Maximum Strength

The up-front costs for our favorite milk thistle supplements range from $19.99 to $34.99 — notwithstanding certain pricing variables, like subscription discounts, promotions, and size options. Because no recommendation on our list is prohibitively expensive, and some brands advise users to take multiple servings daily, we looked past sticker prices and per-serving breakdowns and chose our cost winner based on per-day use.

When we ran the numbers, we found that NOW Foods easily beat out its competitors in the cost department. A bottle of Milk Thistle Extract Maximum Strength contains 90 capsules, and with one capsule being the daily overall serving size, a single purchase amounts to $0.39 per day and should last around three months.

Life Extension, whose Advanced Milk Thistle comes in two size options, is our runner-up for cost. The 60-count bottle sells for $21 (enough to last a month), so daily use of the supplement amounts to $0.70; with the 120-count ($34.50, a two-month supply), it's $0.56 per day.

HUM Nutrition takes the third spot for cost. A 60-capsule bottle and a two-capsule daily serving amount to a daily consumer cost of $0.87.

The other two milk thistle supplements that we recommend are considerably less cost-effective than the above. Their per-serving prices seem reasonable until you see that you have to take multiple servings daily. Thus, a 60-capsule bottle of either Nootropics Depot or Legendairy Milk will run you $1.75 and $1.90 a day, respectively. The 180-capsule bottles of each are more reasonable but still significantly higher than any of the others, at $1.17 and $1.50 per day.

Convenience

Winner: HUM Nutrition Wing Man

Since all of our top milk thistle supplements have the same route of administration (capsules or softgels), we concluded that customer convenience depends on the aggregate of other determinants, namely dosing instructions, pill sizes, and subscription options.

No single milk thistle brand on our list fully satisfies all of the above sub-criteria, but HUM Nutrition comes the closest. This chart explains how:

And here’s a visual comparison of the pill size of each of our top picks:

As you can see from the image, HUM’s Wing Man is both smaller and narrower than the other milk thistle options. In our tests, its smaller size certainly translated to easier administration. And although HUM is exclusively a subscription service with 30-day deliveries, we concluded the default interval was appropriate for a daily supplement, and the company’s flexible enough to allow immediate cancellation for those who want just a single order.

Life Extension is our runner-up for convenience because it’s a softgel. Though it’s a bit larger than HUM, its softer form makes it a little easier to swallow than a rigid capsule. Also, the company has the widest range of delivery intervals on our list, as well as two bottle-size options: 60- and 120-count. If you want to space out your subscriptions and don’t mind a slightly bulkier capsule, then Life Extension is an excellent choice.

Legendairy Milk rates third in the convenience category primarily because it has a subscription option and its capsules are smaller than the NOW Foods and Nootropics Depot counterparts. Unfortunately, it also has the largest serving size at six capsules.

NOW Foods and Nootropics Depot don’t rate as high in our estimation because their capsule sizes are significantly larger compared to the others and they don’t have any direct subscription options. If you want to subscribe, you’ll have to do so through Amazon — which is well and good except that it takes away the option for returns.

For the quickest comparison of our top milk thistle brands, see the following reference chart summarizing each supplement's key qualities and selling points:

Milk thistle is a flowering herb that's native to Europe but also found in the Americas. It has a long history of use as a botanical remedy dating back to the fourth century BCE, when ancient Greeks regarded it as a general medicinal herb.1 Since then, it has been used to treat an array of ailments, including but not limited to:

• Hepatitis
• Cirrhosis
• Jaundice
• Diabetes

The active ingredient in milk thistle is silymarin, a group of flavonoids that comprises silybin, silychristin, isosilybin, and silidianin.11 Silymarin is what’s known as a free radical scavenger, otherwise known as an antioxidant. What free radical scavengers do is neutralize unstable molecules (free radicals) that cause oxidative stress, which, if left unchecked, could lead to or contribute to serious health concerns such as acute liver injury and chronic liver diseases, to name just a couple.12 13 The most abundant compound in silymarin is silybin. It makes up 50-70% of silymarin’s structure and may have the best radical-scavenging potential of all the constituent flavonoids.11 14

In the supplements space, "milk thistle" and "silymarin" are often interchangeable terms, as silymarin is the key player behind milk thistle's purported health benefits. Thus, manufacturing a milk thistle supplement entails extracting silymarin from the seeds, often at 70-80% standardized concentrations.15 Practically all of our top recommendations — NOW Foods, HUM Nutrition, and Nootropics Depot — fall within that range or exceed it. Life Extension has a lower concentration but theoretically superior bioavailability because of its addition of phytosomes. Legendairy Milk doesn't specify its quantity of milk thistle, much less the concentration of silymarin.

Varying degrees of research indicate that milk thistle may offer a fairly broad range of health benefits, principally owing to its radical-scavenging activity. Below, we discuss the most promising applications for milk thistle supplements.

Liver protection

Milk thistle is probably best known for its liver-protective potential, and several studies support its use toward that end. In 2007, for example, a study found that participants with nonalcoholic fatty liver disease saw a "significant reduction" in disease indicators after treatment with silymarin in a phospholipid complex (sort of like the type used in our overall winner, Life Extension). The researchers thus concluded that such an intervention could be used to complement the treatment of chronic liver damage.16

A fairly recent review published in 2020 affirms that silymarin can be effective as a supportive treatment for liver diseases. The researchers highlighted silymarin's liver-protective effects in cases of drug-induced liver injury, fatty liver disease (both alcoholic and nonalcoholic), and alcoholic cirrhosis, attributing successes to the compound's ability to prevent cytotoxicity by reducing oxidative stress on the liver.3 Many of the studies covered in the review administered 420mg of silymarin per day. Our recommended milk thistle supplements from Life Extension, NOW Foods, and HUM Nutrition exceed that amount; Nootropics Depot falls short, while Legendairy Milk doesn’t specify its silymarin quantity.

Diabetes

In our extensive analyses of milk thistle's health applications, we came across two important pieces of research demonstrating its potential as a therapeutic intervention for diabetes.

The first is a randomized, double-blind, placebo-controlled clinical trial published in Phytotherapy Research in 2006. In it, a group of 25 patients with diabetes were treated with 600mg of silymarin per day, divided into three doses. Compared to the placebo group, those who received the silymarin saw a "significant decrease" in their levels of key diabetic markers — hemoglobin A1C, fasting blood sugar, total cholesterol, low-density lipoprotein ("bad") cholesterol, and triglycerides.17

The second is a recent review published in the Annals of Hepatology in 2021, much of which relates to silymarin's effect on insulin resistance,18 a prominent marker for type 2 diabetes.19 Two of the studies referenced in the review were animal studies that administered 26.25-100mg/kg of silybin to rat subjects (equivalent to around 366-1,395mg for an 86kg, or 190lb, human) across 6-12 weeks. In both studies, insulin resistance improved in the silybin-treated rats.18

Lactation

In addition to being an herbal intervention for liver diseases and type 2 diabetes, milk thistle also has a long history of use as a botanical galactagogue, or a natural substance believed to increase breast milk production.

Reliable studies on silymarin's utility as a galactagogue aren't exactly numerous, but at least one blinded, placebo-controlled trial from 2008 is worth examining. The trial involved 50 lactating women randomized into either a treatment group or a placebo group. The treatment group received 420mg/day of micronized oral silymarin for 63 days. In the end, the researchers found an 85.94% increase in daily milk production in the treatment group, compared to 32.09% in the placebo group. They concluded that silymarin is safe and effective as an herbal galactagogue, capable of boosting lactation without affecting breast milk quality.20

We should mention that some sources say to avoid using milk thistle while breastfeeding, as one can't conclusively attest to its safety for either the mother or the infant based on the current research. However, the Drugs and Lactation Database (LactMed), a definitive resource on such matters, states that milk thistle is "unlikely to adversely affect the breastfed infant" and that it's "generally well tolerated in adults with only mild side effects.”21 Of course, no supplement is without its risks, so if you're considering milk thistle as a lactation aid, we recommend speaking with your doctor to confirm its suitability for you and your baby.

Cancer

People who undergo chemotherapy (the primary treatment for most cancers) may receive milk thistle because chemo can lead to liver toxicity, particularly when it comes to treating acute lymphoblastic leukemia (ALL).22 In one study involving 40 patients with ALL undergoing chemotherapy, the researchers observed liver toxicity in 15% of subjects.23 Fortunately, milk thistle may be able to reduce the associated risk of mortality. Indeed, a pilot study on young patients with ALL suffering from chemo-induced liver toxicity found that treatment with milk thistle led to a "trend towards significant reductions in liver toxicity."24 The researchers state that future studies are needed to zero in on the ideal dosage and duration of treatment, but their findings suggest that milk thistle may be a promising intervention for acute liver injury secondary to chemo.

Milk thistle might also function as an anti-cancer agent. A 2021 review published in Biomedicine & Pharmacotherapy explains that silymarin, the main active compound in milk thistle, can:25

• Regulate the cell cycle, helping to ensure proper division and replication
• Induce apoptosis, or programmed cell death, by which the body can eliminate mutated cells (e.g., cancer cells)
• Regulate the body's immune response, increasing its ability to recognize and attack cancer cells
• Keep tumor cells from growing and spreading
• Inhibit angiogenesis, the process by which tumors create new blood vessels that increase their blood supply and help them grow

The review specifically discusses silymarin's therapeutic potential for gastrointestinal cancer, but as another set of researchers note, silymarin has a pleiotropic effect, meaning it can act on multiple targets.26 Again, more research may be needed, but the current science suggests that milk thistle may have fairly broad complementary utility in cancer therapy.

Skin and aging

Several studies have looked into milk thistle’s viability as a dermatological or anti-aging product, as outlined below:

An important caveat to consider is that all of our top recommended milk thistles are oral supplements, and research on oral milk thistle for the above purposes is somewhat lacking. However, the available research gives reason to be optimistic about the products in our guide.

Milk thistle is generally considered safe at therapeutic doses. We've noted that research generally recommends 200-600mg as the effective range for most users. Studies show it may be well tolerated in higher doses of 700mg three times a day, as well, with few to no adverse effects when taken as an oral supplement (but we don’t recommend taking more than what a supplement manufacturer instructs).31

That's not to say that adverse effects aren't out of the question; the most severe reaction would be anaphylaxis, which is life-threatening. Therefore, you should avoid milk thistle if you're allergic to the Asteraceae or Compositae plant families (which, aside from milk thistle, include chrysanthemums, daisies, sunflowers, and marigolds).

A 2007 review published in Integrative Cancer Therapies also warns of the risk of hyperbilirubinemia and elevated ALT levels in cancer patients treated with a silybin-phytosome complex. But it's important to note that the subjects received abnormally high doses (10-20g per day), and supplement users who adhere to a manufacturer’s recommendations are highly unlikely to come near that amount.32

Several drug-drug interactions are possible, too. Drugs.com advises that people who take deferiprone or simeprevir should avoid milk thistle supplements, given the risk of abnormal liver function tests and acute liver injury. Milk thistle may also interact with the following medications, though the interactions are less concerning and only require monitoring after ingestion:2

• Fosphenytoin-phenytoin
• Indinavir
• Losartan
• Metronidazole
• Sirolimus
• Tolbutamide
• Vitamin K antagonists

On the brighter side, most adverse reactions to milk thistle are minor and brief. The most common side effects of oral silymarin ingestion include:2

• Abdominal pain/fullness
• Bloating
• Bowel changes
• Diarrhea
• Dyspepsia (indigestion)
• Flatulence
• Headache
• Nausea
• Pruritus (itching)

Of note, there's at least one case report of more severe instances of the above, along with sweating, colicky pain, weakness, and collapse, in a 57-year-old woman after taking a milk thistle capsule. However, the report describes the woman's symptoms as "idiosyncratic" and concedes they may have been caused by another ingredient in her supplement.33

Even if you feel that your risk of adverse events is low, we recommend speaking with your doctor before incorporating milk thistle (or any supplement) into your regimen. With their training and knowledge of your medical history, they should have the most complete sense of what supplements are appropriate for you.

Anyone concerned about their liver health may be interested in taking a milk thistle supplement, as milk thistle is well known for its radical-scavenging activity and associated liver-protective properties. Oral milk thistle supplementation may also benefit those with type 2 diabetes who are striving to control their blood sugar levels, as well as chemotherapy patients concerned about liver toxicity secondary to their treatment.

Milk thistle has a long history of use as a lactation aid, too, so new mothers might look into taking a supplement like Legendairy Milk, which features a blend of common galactagogues. However, relatively little research is currently available on milk thistle's overall safety for those who are pregnant or breastfeeding, so you should first consult with a medical professional to assess its place in your regimen.

As with all supplements, some people should avoid milk thistle altogether, primarily individuals who are allergic or sensitive to Asteraceae and/or Compositae plants and those currently on medications that may severely interact with silymarin (e.g., deferiprone or simeprevir).

Additionally, please be mindful of other ingredients in the milk thistle supplement you choose. Products like Legendairy Milk's Liquid Gold and HUM Nutrition's Wing Man include additional botanicals that have the potential to cause adverse or even allergic reactions. Read the labels carefully and, again, consult with a doctor to help ensure your safety.

Best overall

Life Extension is a Florida-based health and wellness company with a pedigree spanning more than 40 years. Founded with a focus on improving human longevity, the company not only sells a tremendous range of dietary supplements geared toward various health goals but also provides free personalized health consultations with specialists, funds anti-aging and disease research, and sells a number of lab tests, including but not limited to hair loss panels, blood panels, and mold exposure tests. (You can learn more about Life Extension as a company in our dedicated company review.)

Our focus in this guide, however, is Life Extension’s Advanced Milk Thistle supplement.

A serving (two softgels) of Life Extension’s Advanced Milk Thistle provides 480mg of silymarin along with 227.52mg of total silybin and 48mg of isosilybins A and B. Remember, silymarin is the active ingredient in all milk thistle supplements and the bioactive compound responsible for their potential health benefits. It also isn't all that soluble in water, so only around 20-50% of it is bioavailable to the human body.3

The quantity of silymarin in Life Extension may be lower than that of NOW Foods or HUM Nutrition, but it's integrated with phospholipids. A phospholipid is a kind of fat molecule that's both lipo- and hydrophilic. As put by the authors of a 2019 review on drug-phospholipid complexes, the combined affinity for fats and water means that phospholipids function as emulsifiers that enhance absorption — and, therefore, bioavailability.4

Indeed, a 1990 human study found that a silymarin-phospholipid complex resulted in plasma levels of silybin (silymarin's main active component) that were more than double the amount provided by an equal quantity of pure silymarin — 298ng/mL versus 102ng/mL per 120mg of silybin.34 Given the science behind phospholipid-based drug delivery, we can conclude that Life Extension is likely capable of delivering more per-dose silymarin, as well as isolated silybin, than either NOW or HUM (neither of which uses phospholipids).

As for the silybin, 180mg of it comes from the Milk Thistle Phospholipid Proprietary Blend, while the remaining 47.52mg is part of the Siliphos. We mentioned earlier that Indena, the company that makes Siliphos, has conducted its own studies into its efficacy, the highlights of which are:64

• Bioavailability: Oral Siliphos was found to absorb into the bloodstream and be analytically detectable within minutes, and then remain stable within plasma for over six hours. Indena states the findings are an improvement over ordinary silybin.
• Liver health: In a human trial involving 85 subjects, participants who received Siliphos saw positive effects on ALT, γ-glutamyl transpeptidase (an important enzyme found in high levels in the liver), and insulinemia (a state of high insulin in the blood).

Indena’s studies were self-conducted, which presents the opportunity for bias, but we also acknowledge they were peer-reviewed, and the research probably wouldn’t be available had the company not taken the initiative. Plus, considering the other studies we’ve seen and referenced on phosphates, we can confidently say that Siliphos has the potential to improve absorption and bioavailability.

Life Extension sells a vegetarian alternative, by the way (the original formulation contains gelatin and beeswax). It's available only in a 60-count bottle, costs a bit more ($23.50-$26.25), and has a different formulation (750mg of milk thistle extract with no phospholipids and no Siliphos). Given its absence of phospholipids, we consider it separate from the product we recommend here.

Pricing, subscriptions, and returns for Life Extension Advanced Milk Thistle

The price you pay for Life Extension Advanced Milk Thistle depends on a couple of factors. See the chart below for a breakdown of your options, as well as the up-front and per-day cost of each:

Life Extension Advanced Milk Thistle is on the lower end of the cost spectrum (only NOW Foods has a lower per-day cost). A subscription nets you an 11% discount, and you can choose from a wide range of delivery intervals — anywhere from one to 12 months.

At checkout, your payment options are:

• Credit card
• PayPal
• Google Pay

Shipping is free for subscription orders. Otherwise, all domestic shipping costs are flat rate. Standard shipping (3-5 days) adds $5.50 to your purchase, Puerto Rico included. Expedited shipping runs $12.50 for UPS second-day air and $21.50 for UPS overnight. Deliveries to Canada cost $19.50 for USPS Priority International. Life Extension ships internationally; air mail costs apply.

If you aren't pleased with your order, you may be happy to know that Life Extension's return policy is very generous. You have 12 months from your purchase date to send it back for either a replacement or a full refund. The policy applies even to used supplements, no matter how many doses remain. For perspective, NOW, HUM, Nootropics Depot, and Legendairy Milk all have 30-day return windows and provide refunds only for unopened items.

Coincidentally, we’ve had firsthand experience with Life Extension’s return policy. We ordered Advanced Milk Thistle in the regular formulation but ended up receiving the vegetarian one — an error that initially went unnoticed. After speaking with Life Extension’s customer support several weeks into our use of the supplement, the company happily offered to ship us the correct order and allowed us to keep the vegetarian capsules we’d mistakenly received.

Best budget pick

NOW Foods is a well-established entity in the supplements space. Its place as our budget pick probably isn't all that surprising, seeing as the company has featured in several of our guides in precisely that capacity, and it's quite well-known among supplement users for producing affordable yet high-quality products.

NOW Foods Milk Thistle Extract Maximum Strength costs $34.99 and delivers 750mg of milk thistle extract, with 600mg of silymarin standardized to 80% — likely sufficient to deliver the minimum 200mg to render potential health benefits.2 At first glance, you might reckon it isn't any less expensive than Nootropics Depot and is actually more expensive than Life Extension and HUM Nutrition. But that's true only in terms of the up-front cost. When you consider that NOW requires only a one-capsule-a-day dosage and a bottle contains 90 capsules, it becomes clear that:

• A single bottle should last around three months.
• The per-day use cost is just $0.39 — almost half as much as a 60-count bottle of Life Extension’s milk thistle.

On top of the low cost, NOW Foods' milk thistle comes with an impressive safety pedigree. For instance, the company (like our other top picks) manufactures its supplements in GMP-compliant facilities, which the World Health Organization describes as an indicator of products that are "consistently produced and controlled according to quality standards."35 Then there’s the fact that NOW tests its products in ISO-accredited labs, which indicates conformity with international standards for scientific testing processes. As a cherry on top, NOW's Milk Thistle Extract Maximum Strength is certified non-GMO and vegan.

On the less-than-ideal side of things, we feel that testing supplements in-house, ISO accreditation or not, is less dependable than using an independent third party. In terms of safety, you can be more certain of objectivity with the latter. NOW's capsule size is quite large compared to Life Extension, HUM Nutrition, and Legendairy Milk, whose capsules are shorter and narrower. Similar to most of our other picks — except for HUM — NOW Foods Milk Thistle Extract Maximum Strength may pose some difficulty to users who struggle to swallow pills.

Pricing, subscriptions, and returns for NOW Foods Milk Thistle

As we said, NOW Foods Milk Thistle Extract Maximum Strength is $34.99 for a 90-capsule bottle, which equates to a daily use cost of only $0.39. In contrast, Life Extension, our runner-up for cost, is 25% more expensive per day, even at its most affordable tier. But note: we recommend buying it from the NOW store on Amazon, where the price for this product tends to be even lower.

When the time comes to pay, your options are:

• Credit card
• Debit card
• PayPal

For orders under $50, standard shipping (2-8 business days) adds $6.95 to the total. Orders above $50 qualify for free shipping. NOW Foods does not ship internationally.

Unlike Life Extension, HUM, and Legendairy Milk, NOW Foods doesn't have a subscription program, so don't expect to set up regular deliveries or see any associated savings if you purchase direct.

Fortunately, if you prefer the ease of auto-shipments, you have the choice to purchase NOW products through the company’s Amazon storefront. There, the base price for the maximum-strength milk thistle is actually far less expensive — 42% less expensive ($21.42 up-front, $0.24 per day) when we were testing products — and a subscription cuts the cost by an additional 5% ($20.35 up-front, $0.23 per day). Delivery intervals are diverse, too, ranging from as little as two weeks to as long as six months. Of course, unless several other people in your household will be taking the supplement, you'll probably want an interval somewhere in the middle of that range, as a single user can get three months of use from a single bottle.

NOW Foods’ return policy is similar to the other brands in our guide, save for Life Extension. If you buy direct, the company allows returns of new, unopened purchases within 30 days for a full refund, though return shipping is on you. The same time frame applies to damaged and wrongly shipped items, for which the return shipping is covered by NOW. (The policy doesn't apply if you purchase through Amazon, which doesn't accept returns of any dietary supplements for food safety reasons.)

Best for liver health and the most convenient

HUM Nutrition is a subscription supplement service specializing in numerous areas of health and wellness. The Wing Man supplement, part of the company's detox line, is specifically formulated to promote liver health.

Silymarin itself is well known for its liver-protective properties, which we discussed earlier, though the 600mg provided in Wing Man may potentially fall short of clinical doses after you account for the compound's naturally low bioavailability.3 However, the HUM Nutrition formulation helps make up for the potential deficiency with two additional liver-protecting ingredients:

Wing Man has a couple of other qualities to recommend it as a milk thistle supplement. One is its pill size; the capsules measure just seven-eighths of an inch and have a narrow circumference, making them the easiest to swallow among our top recommendations. In contrast, NOW Foods’ and Nootropics Depot’s capsules measure about an inch and are visibly broader in circumference. Life Extension and Legendairy Milk are close enough to seven-eighths of an inch, but they, too, have wider circumferences.

Safety measures are another upside. HUM's supplements are manufactured in GMP-compliant facilities and are third-party tested, both of which are key baseline measures for ensuring product purity. Plus, all of the company's products are Clean Label Project-certified, which verifies their adherence to strict labeling practices (i.e., customers can be certain of getting exactly what's listed on the product label).42

Pricing, subscriptions, and returns for HUM Nutrition Wing Man

An auto-ship subscription to HUM Nutrition Wing Man costs $26. It's the second-lowest up-front cost on our list, outside of supplements purchased through Amazon. Only Legendairy Milk’s Liquid Gold in the 60-capsule bottle is less expensive, except that amounts to just a 10-day supply versus HUM Nutrition's 30-day quantity.

You can choose between two subscription plans: Month-to-Month and VIP. With the Month-to-Month plan, you get a fresh shipment of supplements every 30 days and have the freedom to cancel, pause, and modify your subscription whenever you want. The VIP option requires that you make a minimum of three monthly orders before canceling but with the trade-off of an additional 20% discount on every order. Should you cancel before reaching the three-order threshold, HUM will charge you the difference in the savings you've realized to date.

Because HUM Nutrition is exclusively a subscription service, it doesn't outright offer the option for one-time purchases. That's a downside, but not a big one. To approximate the single-purchase route, all you have to do is choose a Month-to-Month subscription and cancel it before your next order goes through. Alternatively, you can purchase through HUM’s Amazon storefront.

Another potential downside is that credit cards are the only form of payment that HUM accepts.

Shipping from HUM costs $5.95 for domestic orders under $50. For orders above $50, shipping is free. Additionally, the company ships internationally at a flat rate of $12.95.

Only unopened HUM products qualify for refunds (minus shipping costs). You can still return an opened bottle of Wing Man, but you'll get store credit instead of a refund. As with NOW, Nootropics Depot, and Legendairy Milk, your return window is just 30 days.

Best for diabetes support

The main selling point of Berberine HCL + Silymarin is that it delivers 500mg of berberine, a naturally occurring chemical compound, in every serving. Nootropics Depot advertises the product as being effective for "cellular support, metabolic function, and cognition," none of which are typically associated with silymarin. That, along with the low 100mg silymarin dosage, should tip you off to the fact that milk thistle plays only a supporting role in the formulation.

Nootropics Depot itself claims the silymarin is meant to increase the uptake of berberine, which (like silymarin) has a low bioavailability when taken orally. The claim holds water according to a 2019 meta-analysis, whose authors note that a berberine-silymarin complex can indeed produce "satisfactory results" in increasing berberine's bioavailability.43

The same meta-analysis examined the metabolic effects of combining berberine with silymarin. After reviewing five eligible randomized clinical trials involving 497 total participants, the authors found that berberine and silymarin coadministration could lead to an "advantageous improvement in lipid and glucose profile" — namely, it could lower total cholesterol, low-density lipoprotein ("bad") cholesterol, and triglycerides while increasing high-density lipoprotein ("good") cholesterol.43 Such impacts are why berberine may be particularly useful to people with type 2 diabetes. After all, high glucose levels often correlate with high cholesterol, which itself correlates with diabetes, per the American Heart Association.44

Several studies have examined berberine's effects on diabetes more directly. For example, in 2008, researchers in China undertook a three-month trial to assess the hypoglycemic effect of berberine versus metformin, a common prescription used to control the blood sugar levels in people with type 2 diabetes. What the researchers found was that berberine performed similarly to the prescription, successfully producing "significant decreases" in hemoglobin A1C, fasting blood glucose, postprandial blood glucose, and plasma triglycerides.45 Importantly, the study used 1,500mg of berberine per day (500mg servings, three times daily), which is the same amount you’d take in a day’s worth of Nootropics Depot’s Berberine HCL + Silymarin Capsules.

Another study using the same berberine dosage yielded similarly positive outcomes on metabolic and blood lipid markers. It also reported some mild weight loss (average 5lb) in subjects with obesity,46 and we know that losing weight can have a tremendous impact on one's diabetes prognosis.47

So, all things considered, Nootropics Depot's Berberine HCL + Silymarin Capsules are certainly a promising supplement for diabetes support.

Pricing, subscriptions, and returns for Nootropics Depot Berberine HCL + Silymarin Capsules

Nootropics Depot Berberine HCL + Silymarin is available in two sizes and price points:

• 60-count: $34.99
• 180-count: $69.99

A serving is one capsule, but you're to take three servings per day, so a single bottle should last you 20-60 days. That translates to a per-day use cost of $1.75 for the 60-count bottle and $1.17 for the 180-count.

Like NOW Foods, Nootropics Depot doesn't offer direct subscriptions. Hence, there's no auto-ship discount if you buy directly from the company, and you'll have to monitor your supply and repeat your order accordingly to keep it in stock.

The product is available on Amazon, however. At the time of this writing, an Amazon subscription to the 60-count bottle is slightly more expensive than a one-time direct purchase ($36.09), but the 180-count bottle is less expensive ($67.49).

Credit card and PayPal are your only payment options when buying directly — not as limited as HUM Nutrition but more so than the other options on our list.

If you purchase directly from Nootropics Depot, domestic orders of $50 and above ship for free via USPS Priority Shipping, and orders of at least $80 get free shipping via FedEx 2-3 Day Shipping. Otherwise, the shipping fee can be quite steep (around $10 to most locations in the contiguous United States). With that in mind, you may want to opt for the 180-count bottle, which qualifies for free shipping.

Nootropics Depot does ship internationally. Only orders of $200 and above qualify for free international shipping, and you may be subject to additional fees, such as those for customs clearance.

For direct purchases, the company's return policy applies only to unopened and unused products (and Amazon doesn’t accept returns on supplements at all). You have 30 days from the delivery date to initiate a return for either a refund or store credit. You bear the responsibility for return shipping costs.

Best for promoting lactation

Legendairy Milk is a brand that caters to breastfeeding mothers. Its Liquid Gold supplement is formulated specifically to boost lactation supply.

Every two-capsule serving of Liquid Gold delivers 1,040mg of a proprietary blend that consists of milk thistle, goat's rue, shatavari, fennel, alfalfa, and anise. All six ingredients are common botanical galactagogues. We discussed earlier how milk thistle can affect lactation. Below is an overlook of Liquid Gold's other ingredients and each one's potential to increase breast milk volume:

Liquid Gold's formulation is a proprietary blend, but unlike Life Extension, its label gives no clue as to individual ingredient quantities. To get a sense of its potential efficacy, we have to make an educated guess that weighs the total blend's dosage against the lowest effective dose of each component.

So, we know the proprietary blend amounts to 1,040mg per serving, and you're supposed to take three servings (3,120mg in total) per day. We also know that the lowest effective doses in the studies we've seen are 300mg of goat's rue, 600mg of shatavari, 600mg of fennel seed, and 2g of anise, and milk thistle studies have seen positive effects in doses as low as 420mg. Because ingredients are listed in descending order by weight, we can assume that goat’s rue, milk thistle, and possibly shatavari are the ingredients most likely to be at the effective doses, and all three have shown varying degrees of efficacy as lactation aids. Knowing all of that, we feel that Liquid Gold can be a worthwhile option to try for breastfeeding mothers looking to increase their breast milk supply.

Pricing, subscriptions, and returns for Legendairy Milk Liquid Gold

A 60-capsule bottle of Liquid Gold costs just $19.99 as a one-time purchase direct from the manufacturer; as a subscription, it's $17.99. The up-front cost is the lowest among our top recommendations, but the per-day use cost is the highest at almost $2.00 — more than five times as much as NOW Foods and almost four times the daily cost of Life Extension. The reason is that Legendairy Milk recommends taking six capsules a day, which means that a 60-capsule bottle would last just ten days. The larger, 180-capsule bottle (a 30-day supply) offers a slightly more economical value with a per-day use cost of around $1.50, which at least brings it below Nootropics Depot’s 60-count bottle in terms of daily expense.

On a more positive note, choosing an auto-ship subscription gets you a 10% discount on the base price — $17.99 for 60 capsules and $40.49 for 180. The per-day use cost subsequently drops to around $1.80 and $1.35, respectively.

For delivery intervals, your options for either product size are ten days and 30 days. Nothing's stopping you from buying a $17.99 subscription and stretching your supply across the longer interval (effectively reducing your per-day cost to around $0.60), but you're likely to experience reduced efficacy as a result.

At checkout, your payment options are:

• Credit card
• PayPal
• Shop Pay (eligible for installments)

Domestic orders of $75 and up get free shipping. Otherwise, shipping costs are contingent on your location — that includes international orders, for which additional fees (e.g., import taxes and duties) may apply. Domestic purchases also qualify for a refund (minus shipping costs) as long as the product is unopened. As with Life Extension, HUM, and Nootropics Depot, you have 30 days from the original delivery date to initiate a return.