Seed Probiotic Reviews

If you're like us, the terms "microbiome" and "gut–brain axis" probably make frequent appearances in your online search results, maybe even your everyday speech. We're referring, of course, to the billions of helpful bacteria that live in and on your body and the far-reaching effects they can have in multiple areas of your health.

Seed is a specialist in the space that offers three products aimed at correcting, improving, and optimizing your microbiome. It certainly has plenty of market competition, so we understand if you feel overwhelmed by choosing between it and its competitors. We've written this review to help you make the decision and determine where Seed stands in the probiotics landscape.

Seed’s three synbiotic products, each aimed at a different demographic, contain clinically relevant numbers of live, viable bacterial strains, many of which have scientific research to support their purported health benefits. The company’s practices — in terms of production, safety, and sustainability — are admirable, too, and the shipping costs are either nil or very low. However, the formulations may also contain strains that have little evidence behind them, and the cost of a Seed subscription is higher than most comparable products, so certain consumers may prefer to go with a more cost-effective alternative whose ingredients have greater scientific backing.

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.

Our Seed probiotics review involved 100 relevant sources and more than 50 research hours. We closely read dozens of scientific papers relevant to the ingredients found in Seed's formulations and assessed the company's processes to evaluate product efficacy, safety, and convenience. Research aside, we also took on the customer role, as practical knowledge plays an integral part in every review we write. We not only interacted with Seed's customer support but also purchased Seed products, tried them to the extent we could, and recorded our observations. Our efforts have allowed us to present a well-rounded perspective on the company's offerings and the Seed user experience.

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

Our evaluations of Seed probiotics centered on the five criteria we believed were most likely to influence readers’ purchasing decisions: efficacy, safety, cost, convenience, and sustainability. Efficacy, safety, and cost are typically our principal evaluative factors because we want consumers to gravitate to products that work well without endangering them, and we want our recommendations to be accessible to the widest possible audience. As for convenience, we think a straightforward route of administration correlates with easier daily use, which is bound to influence a person’s overall impression of a product.

Now, sustainability isn’t something we always rate, but it’s such a key part of Seed’s brand identity that we’d be remiss to ignore it.

Here’s how Seed measured up in each category:

Efficacy

A first glance at the company’s formulations tells us Seed does a couple of things right: The probiotics are specified down to the strain, and they’re quantified by the number of viable bacterial cells. Such labeling measures are important because probiotic benefits are often strain-specific,1 and viable cell counts give a sense of a product’s potential to impart its purported benefits.

A closer examination of the formulations reveals some positives and some negatives. The negatives relate largely to strains with little scientific backing, including a large proportion of the bacteria in DS-01 and all three strains in VS-01. What supportive studies we could find were Seed-funded. Self-funding isn’t necessarily a red flag, but it gives some reason to be skeptical of the findings. Also, about those viable cell counts — Seed lists them in groups categorized by intended outcome (e.g., gut health, respiratory health, skin health). The International Scientific Association for Probiotics and Prebiotics (ISAPP) states that 1 billion CFU is the minimum effective quantity per serving,2 which each of Seed's outcome groups exceeds considerably, but the grouped numbering means we can’t tell by the label whether the best-supported strains are present in high enough numbers to truly be effective.

Despite all that, we think the positives are sufficient to earn Seed its 7.0 efficacy rating. For the strains we could corroborate with research (e.g., Bifidobacterium longum BB53 and Bifidobacterium breve BR3), the clinical evidence for their benefits is strong. Also, Seed’s encapsulation methods, including a proprietary dual-capsule system for DS-01, seem quite valid for preserving probiotic viability within the harsh environment of the gastrointestinal (GI) tract, even though the relevant research is self-funded. As to those self-funded studies, we can acknowledge that the study methods were sound, and we don’t dismiss the possibility that future research may validate their findings.

Our rating accounts for our subjective testing as well. While our testers hadn’t experienced much in the way of GI complaints beforehand, they did experience alleviated bloating after trying Seed.

Safety

We can’t defer to the U.S. Food & Drug Administration (FDA) to confirm safety here since dietary supplements such as probiotics are outside the FDA’s purview. Instead, we have to examine a company’s operational practices and ingredient bills to confirm safety.

On that front, Seed does a terrific job. Apart from the probiotics themselves, which the Office of Dietary Supplements describes as "unlikely to cause harm in healthy people,"1 all of the ingredients in Seed’s products are generally recognized as safe. Plus, the company conducts third-party testing at multiple production stages to ensure the products are:

• As potent as stated on the label
• Free of common allergens, such as gluten, dairy, soy, nuts, and shellfish
• Compliant with California’s Proposition 65, verifying that heavy metals are within safe limits

The few safety dings relate to health risks for relatively small populations. For example, the PDS-08 Pediatric Daily Synbiotic contains inulin/fructooligosaccharides as a prebiotic, which isn’t suitable for people who can’t consume fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs).

Cost

Only by the barest margin does Seed avoid being designated as the most expensive synbiotic among our recommendations, and that really only applies to its two daily synbiotics. DS-01 and PDS-08 each cost $49.99 per month, making them a few dollars less than Ritual Synbiotic+ at its normal, undiscounted price. Seed’s cost rating would’ve been a few decimal points higher if the VS-01 Vaginal Synbiotic didn’t average out to a $41.66 monthly price, which is significantly higher by both unit cost and per-use cost than competitors Jarrow and VagiBiom.

What really saves Seed in this category is shipping. All domestic orders ship for free, regular international shipping costs a flat rate of just $10, and overseas customers can opt into free shipping by enrolling in Seed’s Sustainable Refills Program (more on that under the “Cost” criterion).

Convenience

Our testers found DS-01 Daily Synbiotic quite easy to use. It’s a “standard”-size capsule measuring 2cm long and 0.5cm wide (seven-eighths of an inch and one-quarter inch, respectively). As long as you don’t have trouble swallowing pills, Seed’s marquee product should go down easily. The company recommends an acclimation period when you start out, but the system is clearly laid out in the accompanying booklet.

The VS-01 Vaginal Synbiotic is less convenient since it requires vaginal insertion, but discomfort should be minimal for those who are accustomed to using tampons. The applicator is, in fact, no wider than a regular-size tampon, and the probiotic tablet is the same width as DS-01. Of course, if you have a pelvic health condition that prevents intravaginal use (e.g., vaginismus),3 you’ll probably prefer an oral alternative like Jarrow.

We didn’t order the PDS-08 Pediatric Synbiotic, so we can’t speak firsthand about using it, but we appreciate that it’s a microencapsulated powder that children can sprinkle into whatever drink or food they want. A gummy form, like Smarty Pants, might appeal better to some users, but that comes down to personal preference.

Sustainability

Seed is one of the most environmentally conscious brands we’ve reviewed. Practically everything in the box is either reusable or easily biodegradable. DS-01, for example, comes in a glass jar and includes a glass travel vial. You keep the jar and vial, and when you get a refill, which arrives in a compostable pouch, you dump the contents into them. Even the protective “foam” in which the products come nestled is made of materials that can go in either the recycling bin or the compost heap. The only materials we could see that weren’t recyclable or compostable were the VS-01 applicators and their wrapping.

Not only that, but Seed encourages overseas customers to reduce their carbon footprint through its Sustainable Refills Program. Participants agree to pay for three months of product up front in exchange for free international shipping. It may be a small contribution to reducing global emissions, but it’s also an incentive we respect and one we’ve scarcely seen offered by other supplement brands.

Seed is a subscription-only supplement service, like Ritual, but it differentiates itself in that it specializes in broad-spectrum synbiotics. The colloquial understanding of "synbiotic" is a product that combines probiotics (beneficial microorganisms) and prebiotics (food for probiotics).4 5 In a 2020 statement, the ISAPP qualified the definition to recognize two subcategories:6

• Complementary synbiotic: The product fulfills the colloquial definition.
• Synergistic synbiotic: The product contains microorganisms aimed at imparting health benefits and substances specifically selected to support the growth or activity of those microorganisms. An intentionality informs the composition, and the components are meant to work cooperatively.

Seed's entire product line fits the "complementary" designation; the bacterial compositions are thoughtfully assembled to achieve specific outcomes, but the prebiotic component is largely one-type-feeds-all. Being a complementary synbiotic isn't a bad thing, though. The authors of a 2022 review note that almost all synbiotics used in clinical trials are complementary, and many have proven to provide "important health benefits on the tested population."7

As a company, Seed further distinguishes itself from the competition in several key aspects. The following sections describe what we think are three key points of differentiation.

Seed’s probiotic lineup

Seed separates itself from competitors like Ritual and Peak Performance not only in that it specializes in synbiotics but also that it offers multiple synbiotic formulations, two of which serve specific demographics. At the time of this writing, Seed's product line includes three distinctive synbiotic formulations. We'll cover the science behind their respective formulations in the section titled “How do Seed probiotics work?” For now, though, let's discuss what each product entails and the benefits it's designed to achieve.

AFU vs. CFU

You may have noticed by now that Seed measures viable bacterial quantity not by colony-forming units (CFU) but by AFU. So, what's the difference?

CFU refers to a single organism that can produce a colony, or a bacterial population. Think of it as the ancestor from which a complex family tree originally branches, only that each successive generation arises in a matter of minutes rather than decades. Probiotic supplements — including Seed's competitors Ritual and Ombre — typically measure their contents by CFU, with higher numbers corresponding to a larger quantity of helpful microorganisms that can multiply.

Probiotic consumers often equate high CFU with superior probiotic efficacy, but probiotics don't exactly work that way. Some supplements contain filler species that aren't necessarily helpful to the microbiome they populate, but they help inflate the marketable bacteria count. Also, providers count CFU at the time of manufacture, and not all of the bacteria that were viable at the time will remain viable by the time you consume the product.

AFU is another way to enumerate the viable bacteria in a probiotic supplement, though in a potentially more accurate manner. It relies on a technology called flow cytometry, which uses lasers to illuminate dye-marked single cells and detectors to read the light signals.10 A 2023 paper published in Foods describes AFU as a "more precise method ... for counting viable microorganisms" because it can identify microorganisms that survive production but aren't viable.11

With all that considered, we want to note that bacterial cell counts do matter in a broad sense. The more microorganisms that were viable at production, the more likely that you’ll have sufficient quantities to ingest. Also, in a 2014 consensus statement, the ISAPP considers 1 billion CFU to be the minimum effective quantity of microorganisms per serving.2

The key takeaway is that AFU, as used by Seed, can give you a more spot-on sense of a probiotic's ability to proliferate its bacterial cells and, therefore, establish a healthy microbiome.

Sustainability

Most environmental pollution is industrial,12 so we think it's important to highlight companies that demonstrate a strong commitment to sustainability. Seed isn't the only environmental champion in the supplements space, but it takes (and promotes) much stronger measures compared to the competition.

For example, most of the company's packaging is biodegradable. All products come in outer boxes made with algae paper that's FSC certified, which designates a product sourced from "responsibly managed forests that provide environmental, social and economic benefits.”13 With the DS-01 Daily Synbiotic, the contents are protected by an inner "foam" that derives from starch and natural fibers that are suitable for the recycling bin or the compost pile (the DS-01 refill pouches are safe for the compost, too, while the PDS-08 refill sachets consist of 40% post-consumer recycled material). Even the peel-away sticker on the jar is recyclable.

Speaking of the jar, it's reusable. The DS-01 Daily Synbiotic jar is made of thick frosted glass with a 100% post-consumer recycled plastic lid, and the PDS-08 Pediatric Daily Synbiotic is made of aluminum. You're meant to keep the original bottle and dump your refills into it.

The only item that doesn't come in a fully biodegradable mechanism is the VS-01 Vaginal Synbiotic, whose applicator can't be recycled.

For the sake of comparison, consider Ritual's product packaging, which consists of polyurethane. Although it's recyclable, it isn't biodegradable. Indeed, it can take around 450 years to decompose, whereas biodegradable materials take no more than six months.14

Probiotic supplements, in general, work similarly. The idea is to get the beneficial bacteria to the environment you want to target (e.g., the gut), where they compete with pathogenic bacteria, produce beneficial substances, or help bolster your body's immune response.15

A supplement's efficacy relies largely on its formulation and delivery. Ideally, the formulation details its contents down to the strain level because probiotic benefits are often strain-specific,1 and the delivery mechanism should ensure the contents survive their transit toward their target destination. In the following sections, we discuss these variables as they specifically relate to Seed's synbiotic products.

Seed DS-01 Daily Synbiotic formulation

Seed's DS-01 Daily Synbiotic contains 24 distinct strains across four outcome categories:

• Digestive health/gut immunity/gut barrier integrity (16 strains) — 37 billion AFU
• Dermatological health (four strains) — 3.3 billion AFU
• Cardiovascular health (two strains) — 5.25 billion AFU
• Micronutrient synthesis (two strains) — 8.05 billion AFU

In addition, it contains a powerful prebiotic in Indian pomegranate, whose polyphenols induce a "synergistic effect" with probiotics.16 The 400mg prebiotic dose appears to be on the low side, however, as successful studies on human inflammatory bowel disorders have used quantities of 6g per day,17 while mouse studies have used doses equivalent to around 1,100mg in a 70kg (155lb) human.18

The vastness of the DS-01 formulation certainly differentiates Seed's marquee product from direct competitors like Ritual and Peak Performance, but number and variety don't mean anything unless the specific strains are proven to deliver the product's purported benefits.

Below, we discuss the most promising contents in the DS-01 formulation to determine whether it truly can deliver on its health potential.

The information you've just read covers 12 of the bacterial strains in the DS-01 synbiotic. Does that mean half of its active ingredients are ineffective? Not exactly. But it does mean there isn't enough reliable research tying the specific strains to their purported effects.

In some instances, the studies we've found don't relate at all to the health outcomes that Seed claims for a particular strain. Such is the case with Lactobacillus crispatus SD-LCR01-IT; while it's a component of Seed's Digestive Health/Gut Immunity/Gut Barrier Integrity blend, we couldn't find any peer-reviewed research to support its use to that end. We can say that Lactobacillus crispatus as a species is commonly found in healthy human guts,42 but nothing definitive about the strain in question.

For others, the most relevant research we could find was self-funded. One is a 2023 in vitro study financed by Seed on the restoration and enhancement of gut function by the following strains in gut models disrupted by antibiotics or alcohol:43

• Lacticaseibacillus rhamnosus HRVD113-US
• Bifidobacterium lactis SD-BS5-IT
• Bifidobacterium lactis HRVD524-US
• Lacticaseibacillus casei HRVD300-US
• Bifidobacterium breve HRVD521-US
• Bifidobacterium longum HRVD90b-US
• Bifidobacterium lactis SD150-BE
• Limosilactobacillus fermentum SD-LF8-IT
• Limosilactobacillus reuteri RD830-FR

The other is a study examining the mechanisms of action behind the cholesterol-lowering activity of Lactiplantibacillus plantarum LPLDL (part of Seed's Cardiovascular Health Probiotic Blend), whose funding appears to come from the company that produced the LPLDL strain, OptiBiotix.44

We've said in other reviews that self-funded research isn't necessarily bad, but it does leave the possibility that bias informed the findings. We can appreciate, though, that the methods in both studies seem sound for in vitro experiments.

For comparison's sake, direct competitor Ritual Synbiotic+ has a much simpler formulation with well-researched bacterial strains, Bifidobacterium lactis BB12 and Lactobacillus rhamnosus GG.45 46

Another direct competitor, Peak Performance Synbiotic Capsules, also has a simple formulation consisting of three well-studied species — Bacillus coagulans,47 subtilis,48 and clausii49 — but it doesn't specify strains the way Seed and Ritual do.

Against these competitors, Seed DS-01 seems to offer a broader range of health applications, but its comparably low proportion of well-researched strains to novel ones leaves something to be desired.

ViaCap: Seed's DS-01 oral delivery system

Let's imagine for a moment that all of the microorganisms in your supplement survived the transit from the production line to your body. Even then, with oral probiotics, they have to contend with another transit route to reach their target destination: your GI tract. Here, we explain how Seed overcomes the hazards of GI transit.

The stomach is the first major obstacle. To quote a 2021 review, acidic gastric fluid is "extremely lethal to most bacteria," including those contained in a probiotic capsule. Not only that, but "ionic strength, enzyme activity (pepsin), and mechanical churning" can also affect probiotic viability. Species such as Bifidobacterium longum and breve may become "undetectable" within an hour spent in the stomach. That means goodbye to some of those gut and respiratory health benefits.50

Probiotic bacteria that survive the stomach must then face the bile and digestive enzymes in the small intestines. It's here, for example, that Lactobacillus salivarius, a key species for respiratory health benefits, sheds some of its viability.50

Probiotic manufacturers overcome GI obstacles through different encapsulation methods. Seed has developed its own method called ViaCap, which entails protecting the inner probiotic capsule with an outer capsule, both made of hydroxypropyl methylcellulose and intended to preserve the probiotic contents as they travel from the stomach to the colon.

ViaCap is a novel solution, and research so far is limited to a self-funded study from 2021 that used a simulated gut model. The study revealed that ViaCap successfully protected the probiotic contents from the harsh GI environment and delivered bacterial numbers that were "highly comparable" to those within the capsule before experimentation.41 In other words, most of the viable contents in Seed's capsule survived the trip to the colon, where probiotics have their biggest impact.51 For perspective, consider that strain survival rates in the GI environment are normally just 20-40%, per a 2001 analysis.52

Once more, we have to address the limitations of self-funded research, but we acknowledge what this particular study did right. That is, the gut model used was the Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The use of SHIME is significant because it's one of the few models that simulate the whole GI tract,53 so it accurately represents how a supplement reacts to the GI environment. We can be skeptical about the study's financial sourcing but also trust the findings to be fair.

Seed PDS-08 Pediatric Daily Synbiotic formulation

Seed's PDS-08 Pediatric Daily Synbiotic is a powder that can be sprinkled into beverages or foods so that your child doesn’t feel as though they’re taking medicine. The powder is “mildly sweet” (per Seed) as well as microencapsulated, a method shown to protect probiotic contents as they travel through the GI tract.54

The PDS-08 formulation has five bacterial strains in common with DS-01:

• Lacticaseibacillus rhamnosus GG
• Bifidobacterium breve SD-BR3-IT
• Bifidobacterium lactis SD-CECT8145-SP
• Bifidobacterium longum SD-CECT7347-SP
• Lacticaseibacillus casei SD-CECT9104-SP

That leaves two unique strains for gut health and two more for respiratory health. In order of correspondence with their outcome categories, they are:

We're pleased that all of PDS-08's bacterial strains have research to support their intended outcomes. Also, because direct competitors Ritual and Peak Performance don't offer formulations specifically for children, we can say Seed truly stands apart in the pediatric synbiotic niche.

You should know that PDS-08 uses a different prebiotic than DS-01. Rather than pomegranate, its prebiotic blend consists of inulin/fructooligosaccharides from chicory root. Research supports their prebiotic function.61 62 Doses larger than 5g see greater increases in beneficial microorganisms such as Bifidobacterium, so the 6g in PDS-08’s is clinically relevant.61 However, although Inulin/fructooligosaccharides are Generally Recognized as Safe by the FDA, they aren't suitable for people sensitive to FODMAP ingredients.63 64 If you need to follow a low-FODMAP diet, using Seed's PDS-08 synbiotic may cause bloating, cramping, constipation, diarrhea, gas, and other GI symptoms.65

The competitors we’ve mentioned so far, Ritual and Peak Performance, don’t produce synbiotics specifically formulated for young people, so we have to look elsewhere to see where PDS-08 stands in its submarket. Two directly comparable products we’ve found are:

• Smarty Pants Kids Prebiotic and Probiotic Immunity Formula
• Garden of Life Raw Probiotics Kids Cooler Powder

You can think of Smarty Pants as a parallel to Ritual Synbiotic+ since it has a simple, two-piece probiotic formulation with well-researched strains: Bacillus subtilis DE111 and Bacillus coagulans MTCC5856.66 67

Garden of Life, on the other hand, is similar to Peak Performance Synbiotic Capsules in that it doesn’t specify its probiotic strains, but its species — Lactobacillus gasseri,68 Lactobacillus plantarum,69 Bifidobacterium lactis,70 Lactobacillus casei,71 and Lactobacillus acidophilus72 — have demonstrated benefits in areas like immune health, respiratory health, GI function, and many others that we’ll cover in a later section, “Alternatives to Seed probiotics.”

Seed VS-01 Vaginal Synbiotic formulation

The VS-01 Vaginal Synbiotic gives us the simplest formulation of the Seed lineup.

Maltose and calcium citrate make up the proprietary prebiotic-postbiotic complex. Seed doesn’t reveal the quantities of either ingredient, so we can’t tell you whether the doses are clinically relevant. What we do know is that maltose has demonstrated the ability to facilitate Lactobacillus and transition the vaginal microbiota away from BV-related bacteria in rhesus monkeys,73 while calcium citrate has shown potential in rat studies to influence gut microbiota and inflammation.74

The probiotic blend contains just three strains of Lactobacillus crispatus, an important species for establishing an optimal vaginal environment because it can inhibit other bacteria and prevent BV.8 The three strains are:

• LUCA103
• LUCA011
• LUCA009

All three come from a proprietary bank, and the relevant research comes from one Jacques Ravel, who co-chairs Seed’s scientific advisory board. The research in question is a randomized, placebo-controlled clinical trial from 2024 and is a preprint (new medical research that has yet to be peer-reviewed). The participants were all within Seed's target age range (18-54 years old). The researchers tested primarily for safety and secondarily for the abundance of Lactobacillus crispatus in the vaginal environment.75

The trial took place in two parts:75

• The first was to compare VS-01 to placebo, and VS-01 did very well. It not only achieved a "significantly higher relative abundance" of Lactobacillus crispatus but also converted 90% of subjects' vaginal environments to be dominant in the species (compared to 11% by placebo).
• The trial's second part compared the intravaginal form of the VS-01 tablet to an oral capsule variation as well as an over-the-counter oral vaginal probiotic supplement. The intravaginal tablet, which is the form you get when you purchase the product, led to "superior conversion" to a Lactobacillus crispatus environment compared to the other forms and successfully reduced the levels of microbes that can cause BV.

All very promising, though we need to refocus on the fact that the trial is Seed-affiliated and not yet peer-reviewed or published. To reiterate, company affiliation isn't necessarily bad; we must be wary of potential bias, but this particular study's methods appear valid. The trial's preprint status isn't an automatic ding against it, either.76 The findings weren't submitted until late May 2024, and the peer-review process takes up to 14 weeks without delays.77 The thing is, delays are common in the post-COVID sciences space. At the time of this writing, we can allow that the trial may eventually find placement in a peer-reviewed journal, thereby validating its findings. If not, count on us to update our review to account for it.

Now, some vaginal probiotics, like Jarrow Fem-Dophilus, are oral supplements, not intravaginal ones, and there’s conflicting research about local versus oral administration of vaginal probiotics. A series of 14 randomized, controlled trials in 2022 showed the oral route to be more effective at treating BV, though we should note the researchers used specific probiotic strains not found in Seed and in conjunction with antibiotics.78 An earlier study suggests roughly equal efficacy between the two routes of administration but acknowledges the possibility of superior efficacy, not to mention convenience, with oral probiotics.79 Yet an even earlier study stated that local administration led to faster effects compared to oral delivery, with healthful effects presenting in 2-3 days versus seven days.80

We can safely make two conclusions based on the evidence we have. The first is that more research is needed to determine whether one route is better than the other. And second, as both routes demonstrate efficacy at this time, the choice is yours to make.

With that said, Seed’s VS-01 delivery system is promising in that it circumvents an obstacle that oral probiotics face: preserving viability as they travel through the GI tract (discussed in an earlier section, "ViaCap: Seed's DS-01 oral delivery system").

On the broadest level, Seed's three synbiotic products may be helpful to people in their respective target populations who want to take active approaches to their microbiotic health — DS-01 for adults, VS-01 for women, and PDS-08 for young people aged 3-17.

More specifically, though, those who have or are at risk for dysbiosis (microbiome imbalance) stand to realize the greatest benefits from Seed's supplements. For those of you who aren't sure about the current state of your gut or vaginal microbiome, there are signs you can watch for and monitor. With gut dysbiosis, the symptoms are those associated with functional GI disorders — abdominal discomfort, bowel changes, bloating, nausea, vomiting, and a feeling of fullness — while vaginal dysbiosis is characterized by discharge, itching, and odor.81 82

Diet, lifestyle factors, and medications can influence your risk for either condition. Gut dysbiosis is the likeliest to arise in people who don't get enough fiber or exercise, and vaginal dysbiosis is linked to vaginal douching, poor nutrition, and having multiple sexual partners. Smoking, stress, and antibiotic use are additional risk factors for both, and genetics may play a role as well.83 84

If you've experienced any of the above symptoms or your circumstances match those we've mentioned, you could be an ideal candidate for a Seed synbiotic. Of course, before you make your order, you should speak with a doctor to confirm your suitability.

However, certain individuals, even those who might otherwise be ideal candidates, would be better off avoiding Seed and other probiotics owing to safety concerns. According to Harvard Health, people with weakened immune systems should steer clear.85That may include:

• People who take immunosuppressant medications
• People with critical illnesses
• Infants born prematurely

The concern here relates to compromised immune systems. Probiotics come with a small but serious risk of introducing a microorganism that can cause an infection. The U.S. National Center for Complementary and Integrative Health notes some cases of fatal infections and recommends weighing the risks to the benefits before embarking on a probiotic regimen.15 Choosing a supplement with third-party-verified ingredients, like Seed, is one safeguard against possible infection but isn't a guarantee against it. Again, you should consult your doctor to ensure safe use.

An additional exclusion criterion applies to Seed’s VS-01 Vaginal Synbiotic. Because it relies on the user’s natural vaginal lubrication to dissolve the supplement, it may be less effective or ineffective in those with vaginal dryness.

Broadly speaking, yes, Seed probiotics are safe for their intended users. The ODS states that common probiotic species are "unlikely to cause harm in healthy people,"1 and all of Seed's species, if not its strains, are common.

In addition, Seed adheres to rigorous third-party testing procedures at every stage of the manufacturing process to test for potency, survivability, contaminants, allergens, and thermostability, thereby ensuring its products are suitable for the broadest possible range of users. DS-01 and VS-01 are both tested for 14 classes of allergens, PDS-08 is tested for 20, and all three are suitable for vegans. What's more, DS-01 and PDS-08 are tested for heavy metals and compliant with the safe limits as defined by California's Proposition 65.86

However, the ODS warns that probiotics in general present a higher risk for harm in some populations on account of underdeveloped or reduced immune defenses, namely:1

• Preterm infants
• People with severe illnesses
• People with compromised immune systems

Remember, too, that DS-01 and PDS-08, respectively, contain pomegranate and inulin/fructooligosaccharides as prebiotics. Therefore, they aren't suitable for people who are allergic or sensitive to such ingredients.

Even in low-risk populations, probiotics can cause unpleasant side effects. Most are minor GI symptoms (e.g., abdominal pain, bloating, gas, and stool changes). Others are more serious but rare (e.g., fatigue, headache, stress, depression, joint pain/stiffness).87

As with any supplement, we recommend you speak with a medical professional before adding Seed or another probiotic to your regimen.

Seed's synbiotics come at different price points. The following chart breaks down the per-unit and per-use costs of each product when purchased directly from the Seed website:

The DS-01 Daily Synbiotic gives you the option to bundle your supplement in three- and six-month supplies, discounting the per-unit price by 10% ($134.97 per shipment) and 15% ($254.95), respectively. All domestic subscriptions ship for free, international orders cost a surprisingly low $10 flat rate, and overseas customers can earn free shipping by enrolling in Seed's Sustainable Refills Program. The program entails quarterly billing and shipments of three-month supplies, with the $40 yearly savings being a reward for helping to reduce the carbon emissions associated with transit abroad.

For the most part, Seed's pricing structure falls in between its two most direct competitors in the synbiotics space, Ritual and Peak Performance. Ritual is the more expensive option overall; your first order costs $43.20 with a 20% Welcome Offer discount but then increases to $54 per month. Peak Performance is the budget alternative at $34.95 as a one-time purchase and $31.46 for a subscription; also, like Seed, the company offers opportunities for additional savings with three- and six-bottle bundles.

For our testing, we ordered the DS-01 Daily Synbiotic and the VS-01 Vaginal Synbiotic. The time from order to delivery was just four days, as advertised on the Seed website. It arrived in branded packaging, but the branding is distinguishable only from up close; the only thing that curious neighbors might have noticed are two hunter-green-colored parcels marked with tiny Helvetica type. Unless they, too, have researched Seed products, they'd have little reason to conclude they were looking at gut- and vaginal-health supplements.

Here's how our experiences went down with each product we ordered:

Everyone has a unique microbiome, so we understand that Seed's synbiotics may not entirely suit your needs. Fortunately, the probiotics market is vast and growing and likely to include a product that satisfies your personal criteria.

We've mentioned Seed's direct competitors throughout this review. Here, we provide further information about them to help guide your purchasing decision and also discuss indirect competitors that may interest you.

Other synbiotics and vaginal probiotics

The following brands may be appropriate alternatives to Seed's DS-01, PDS-08, and VS-01 supplements:

Custom or targeted probiotics

Custom probiotics are unique formulations specifically tailored to your microbiome, whereas targeted probiotics are pre-formulated options recommended to you based on individual analysis. In either case, the provider formulates or recommends a probiotic product based on the results of an at-home microbiome test.

Our favorite such provider is Viome. For those looking to improve their gut microbiome, we'd recommend the company's Gut Intelligence Test along with the Precision Probiotics + Prebiotics plan. The test entails submitting a fecal sample and, a few weeks later, receiving the results of your analysis. If you subscribe to the Probiotics + Prebiotics plan, Viome will custom-create supplements designed specifically to address deficiencies in your gut microbiome. The test by itself costs $279 (or $169 with coupon INNERBODY), while the subscription comes with a free test and costs $79 per month (or $68 for the first six months with coupon INNERBODY15). Feel free to learn more about Viome in our dedicated review.

Viome doesn't currently offer a vaginal test, however. For that, Ombre may be the better option. For $119 ($89.99 with a subscription), the company will send you a collection kit that asks you to take and submit a vaginal swab. It will then analyze the swab and send you the results. Ombre doesn't make custom vaginal probiotics but will recommend relevant pre-formulated products that are likely to address any issues identified in your vaginal microbiome analysis. Head over to our Ombre review to find out more.