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Does InfiniWell GI Prime work? What is in the capsule and what the trials say

Quick answer

Does InfiniWell GI Prime work? No trial of the finished capsule was found. Its ingredients have separate studies: the 500 mg yeast fermentate improved bloating and fullness scores in the moderate-severity subgroup of an 80-adult, six-week placebo-controlled pilot, and a three-strain Bacillus blend with the same strain codes improved dyspepsia scores in a 60-adult, 37-day trial run by the strain’s owner. ButyraGen at 200 mg reduced belly pain mainly in women in a company-sponsored six-week trial. Amazon reviewers give it 4.5 from 32 ratings, and most of the reviews shown are free-product reviews.

Three figures: 500 mg of EpiCor a day, the same as the label; 80 adults with gut discomfort and constipation for six weeks; and a bloating improvement of P = 0.024 at four weeks in the moderate-severity subgroup.
Source: Pinheiro et al., BMC Complementary and Alternative Medicine, 2017. Chart by SuppleGut, free to reuse with a link to this page.

InfiniWell GI Prime is a three-capsule daily formula that combines four kinds of ingredient: a yeast fermentate, a heat-killed bacterium, a butyrate-releasing ingredient and three Bacillus spore strains. It is sold as a pre-, pro- and postbiotic formula through the brand’s own store, Amazon and practitioner dispensaries. This page sets out what is on the label, what the ingredient studies found and who ran them, and what the reviews can and cannot tell you.

What GI Prime is, and what it is not

A serving is three capsules, and a 90-capsule bottle is 30 servings. The label prints EpiCor dried yeast fermentate 500 mg; IMMUSE (Lactococcus lactis strain Plasma) 50 mg, a heat-killed postbiotic; ButyraGen 200 mg; and a Spore Probiotic Blend of 12 billion CFU made of Bacillus coagulans SNZ 1969, Bacillus subtilis SNZ 1972 and Bacillus clausii SNZ 1971. The other ingredients are rice powder, microcrystalline cellulose, magnesium stearate, silicon dioxide and the hypromellose capsule.

The strains carry codes, but the blend shows one total and no count per strain, and IMMUSE has a weight and no cell count. ButyraGen has no breakdown on the panel; trade press describes it as about 50% tributyrin and about 45% fiber, which would put roughly 100 mg of tributyrin and 90 mg of fiber in the 200 mg. The product does not contain PHGG, glutamine, zinc carnosine, mastic gum or licorice. The page and panel carry no contains or free-from statement; the brand’s sales sheet shows gluten-free, soy-free, dairy-free and non-GMO icons.

The trial of the capsule itself

There isn’t one. We searched Europe PMC and ClinicalTrials.gov for the product and the brand and found no study. The brand’s page cites counts of published articles for each ingredient, which are search counts and not trials of this formula. The brand publishes a certificate of analysis for one lot, dated 2025, from MS Bioanalytical: 12 billion CFU per three capsules, heavy metals measured, no yeast and mold, coliform, E. coli or Staph. aureus detected, Salmonella negative. It does not test the fermentate or tributyrin content.

The evidence for the ingredients

EpiCor, 500 mg (the label dose). A pilot trial in 80 adults with gut discomfort and constipation gave 500 mg a day against placebo for six weeks. In the moderate-severity subgroup, bloating and distension improved (P = 0.033 at two weeks, P = 0.024 at four) and so did fullness (P = 0.004, P = 0.023); stool consistency improved overall (P = 0.023), while stool frequency did not reach significance (P = 0.083 and 0.090). It was funded by the Flanders research foundation (Pinheiro et al., BMC Complementary and Alternative Medicine, 2017).

The three-strain Bacillus blend. In 60 adults with undiagnosed gut discomfort, a blend of the same three strain codes beat placebo over 37 days: bloating (P = 0.048) and total dyspepsia score (P = 0.007) at day 30, total score (P < 0.001) at day 37, with no adverse events. The authors are affiliated with the strain’s owner, and the dose is not in the abstract, so it cannot be compared with 12 billion CFU (Soman and Swamy, International Journal of Colorectal Disease, 2019). SNZ 1969 alone improved colonic transit time (P = 0.031) in 80 healthy adults with mild constipation over eight weeks. We found no separate gut trial of SNZ 1971 or SNZ 1972. In the large IBS network meta-analysis, the B. coagulans strains ranked high for abdominal pain were MTCC 5856 and Unique IS2, not SNZ 1969.

ButyraGen, 200 mg (the label dose). A six-week virtual trial that began with 596 participants gave 200 mg against placebo and measured symptoms by questionnaire only. Belly pain improved significantly against placebo, particularly in women and especially post-menopausal women; the abstract gives no overall numbers (Dosz et al., Nutraceuticals, 2025). Trade press names the ingredient’s maker as the sponsor and reports that 14% more women in the active group improved on gas and bloating. A second, 28-day pilot in 29 healthy adults at 200 or 400 mg a day measured tolerability and gut and blood markers, not symptoms; its authors are also tied to the maker.

IMMUSE. The heat-killed Lactococcus has immune and cold-symptom studies, not gut ones. A meta-analysis of eight trials, by authors at the strain’s developer Kirin, found cough reduced by 0.69 days and feverishness by 0.26 days per 28 days. The athletes’ trial used capsules of 100 billion cells a day, and the label prints 50 mg with no cell count.

Almost every supporting study was run or sponsored by an ingredient maker. The studies enrolled people with mild gut discomfort or healthy adults, not people with a diagnosed gut disease.

How to take GI Prime

The brand’s FAQ says three capsules daily with water, preferably with a meal, or as a healthcare practitioner directs; the label says three capsules daily. The EpiCor and ButyraGen trials ran six weeks and the Bacillus blend trial 37 days, so five to six weeks is the span the evidence covers.

Side effects and who should not take it

The brand’s footer advises consulting a physician if you take prescription medication, have a medical condition or are pregnant or nursing, and says it is not for children. The FAQ calls it generally well tolerated. The label lists no side effects and carries no warning specific to live spores. The one recurring effect reviewers mention is the smell, from the butyrate ingredient.

What the reviews say

The GI Prime-specific pool is small: Amazon, 4.5 from 32 ratings (73% five-star, 7% two-star), with seven of the eight reviews shown marked as free-product Vine reviews. The brand’s own site shows 4.9 from 994 reviews and Trustpilot 4.4 from 115, but both cover every InfiniWell product, mostly peptide, hair and skin items, and neither separates GI Prime out.

Reviewers praise having the ingredients in one capsule, a gut benefit within weeks, and normal-sized capsules. They complain about the butyric smell (“like old buttered popcorn”), the price and the three-capsule serving, and a couple report no noticeable effect. Brand-wide complaints on Trustpilot concern support replies, shipping and subscription timing.

The subscription and refund terms

Subscribe & Save is $76.46 (15% off) with delivery every 30 days and cancellation at any time, per the product page. The refund policy allows a return request within 30 days, in the original condition and packaging, and does not take back items sent without a prior request or sale items. Amazon sells it as non-returnable. In the Trustpilot reviews we read there was one subscription-timing complaint and no cluster of charges after cancelling. Single bottles can be bought one-time on the brand site and on Amazon.

Who GI Prime is for

If butyrate is the specific interest, CoreBiome Tributyrin is a tributyrin product, and Gundry MD Bio Complete 3 pairs tributyrin with a prebiotic fiber blend and probiotics. MegaSporeBiotic is a spore-based probiotic. For the CFU numbers behind probiotic labels, see how many CFU you need.

Cost

One bottle is $89.95 on the brand site, which is $3.00 a day; the subscription is $76.46, or $2.55 a day. Amazon showed $71.96 on a 20% deal against the $89.95 list price, which is $2.40 a day. Shipping is free on U.S. orders over $75 on the brand site. The brand also lists it through practitioner dispensaries such as Fullscript.

The products in this catalog

probiotic InfiniWell GI Prime A three-capsule daily formula combining a yeast fermentate, a heat-killed Lactococcus postbiotic, a tributyrin ingredient and three Bacillus spore strains. Buy it at Amazon$3.00 a day
probiotic Gundry MD Bio Complete 3 A two-capsule daily formula combining a prebiotic fiber blend, tributyrin and two probiotic species. Buy it at Amazon$2.33 a day
postbiotic Peak Performance CoreBiome Tributyrin Postbiotic Butyrate delivered as tributyrin, a fat that releases the short-chain fatty acid in the gut instead of the stomach, with pilot studies and no symptom trial. Buy it at Amazon$1.20 a day
probiotic Microbiome Labs MegaSporeBiotic The spore-based probiotic with a placebo-controlled trial on the finished capsule, measuring what leaks from the gut after a meal. Buy it at Amazon$2.21 a day

Common questions

Does InfiniWell GI Prime work?

No trial of the finished capsule was found. EpiCor yeast fermentate at the label’s 500 mg improved bloating and fullness in the moderate subgroup of an 80-adult trial, and a three-strain Bacillus blend with the same SNZ codes improved dyspepsia scores in a 60-adult trial run by the strain’s owner. ButyraGen at 200 mg reduced belly pain mainly in women in a company-sponsored trial.

What is in InfiniWell GI Prime?

Three capsules contain 500 mg of EpiCor dried yeast fermentate, 50 mg of IMMUSE (heat-killed Lactococcus lactis strain Plasma), 200 mg of ButyraGen, and a spore probiotic blend of 12 billion CFU made of Bacillus coagulans SNZ 1969, B. subtilis SNZ 1972 and B. clausii SNZ 1971. The label gives one count for the three strains, not one each. There is no PHGG, glutamine, zinc carnosine or mastic gum in it.

How do you take InfiniWell GI Prime?

Three capsules daily with water, preferably with a meal, according to the brand’s FAQ, or as directed by a healthcare practitioner. All three can be taken together. The trials of its ingredients ran five to six weeks.

Why does GI Prime smell?

Amazon reviewers attribute the smell to the butyrate ingredient (ButyraGen) and describe it as butyric, like old buttered popcorn, or a little stinky. The reviewers who mention it gave three to five stars.

InfiniWell GI Prime vs a regular probiotic?

GI Prime is not only a probiotic. Its 12 billion CFU is three Bacillus spore strains with strain codes, alongside a yeast fermentate, a heat-killed Lactococcus ingredient and ButyraGen. A regular probiotic capsule usually has live bacteria and little else, so the formulas differ in content; no head-to-head trial exists.

What do the subscription and refund terms say?

Subscribe & Save is 15% off ($76.46) with delivery every 30 days and “cancel anytime” on the page. The refund policy gives 30 days to request a return, in original condition and packaging, and returns sent without a prior request are not accepted. Amazon lists it as non-returnable, and a single bottle can be bought there.

Sources

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