Guide

Does Happy Mammoth Prebiotic Collagen work? The label, the trials and the subscription terms

Happy Mammoth Prebiotic Collagen Protein is a vanilla bovine collagen powder with chicory fiber added, mixed into a glass of water once a day and sold for bloating, trapped gas and irregular bowel movements. What sets it apart from the collagen on the next shelf is the fiber, and what sets it apart from most gut supplements is that every active has an amount printed on the label. This page sets out those amounts, what the trials of collagen and chicory fiber found, how the reviews split by platform, and what the brand’s own terms say about subscriptions and refunds.

What Happy Mammoth Prebiotic Collagen is, and what it is not

The U.S. label (the store at store.happymammoth.com, which sells in dollars) gives a 14.7 g scoop and 24 servings a jar. Per scoop: 11.1 g bovine collagen (Type I and III, printed as “HCP-R”), 1.4 g fructo-oligosaccharides from chicory root and 1 g organic pea fiber. The panel also shows 50 calories, 10 g of protein, 3 g of carbohydrate and 2 g of dietary fiber. Other ingredients are natural flavors, vanilla bean powder and stevia leaf extract. There is no proprietary blend. There are no probiotics and no enzymes: the “prebiotic” in the name is the fiber.

Two things the label does not explain. It prints 10 g of protein beside 11.1 g of collagen, and we found no supplier or brand behind the code “HCP-R”. The brand states triple testing of every batch and GMP certification, without naming a laboratory or certifier, and we found no certificate.

The trial of the product itself

There is none. We searched PubMed and ClinicalTrials.gov and found no study of Happy Mammoth, and no trial under the “HCP-R” name. The trade-press piece on the brand cites general collagen studies rather than a trial of the product. The brand’s store page also makes claims about gut-lining repair, leaky gut and sugar cravings; we found no trial in people of collagen repairing the gut lining.

The evidence for the ingredients

Collagen peptides. The trials are small and point both ways. An open-label, single-arm study of 20 g a day of Peptan collagen for eight weeks in women with a BMI over 25 recruited 40, and only 14 (35%) completed; 13 of those 14 reported fewer digestive symptoms including bloating. With no placebo group and a 65% dropout it cannot show the collagen caused the change, and its authors are affiliated with the collagen maker (Abrahams et al., JMIR Formative Research, 2022). A randomized crossover of 10 g a day for seven days in 20 volunteers before a 70-minute run found no difference in GI symptoms or permeability markers against placebo (Taylor et al., European Journal of Nutrition, 2023). A double-blind crossover of 15 g a day for seven days in 15 women also found no difference in GI symptoms (p ≥ 0.412), with appetite as the trial’s focus (Reynolds et al., British Journal of Nutrition, 2025). A collagen-maker-sponsored trial of 10 g a day for eight weeks in 116 adults with GI symptoms (NCT06937801) is marked completed, with no results or publication that we could find. One scoop here has 11.1 g.

Chicory fiber. In 40 healthy volunteers, short-chain fructo-oligosaccharides raised fecal bifidobacteria at 10 and 20 g a day but not at 2.5 g, and excess gas was more frequent at 20 g (Bouhnik et al., Journal of Nutrition, 1999). This product has 1.4 g, below the lowest dose that showed no effect. In 96 adults with IBS, 20 g a day of FOS did not beat placebo over 12 weeks (58% improved on FOS against 65% on placebo), and in 23 children with IBS up to 19 g of fructans a day caused more bloating and gas than maltodextrin (Olesen and Gudmand-Hoyer, 2000; Chumpitazi et al., 2018). We found no pea-fiber trial for bloating.

How to take Happy Mammoth Prebiotic Collagen

One scoop (14.7 g) stirred into a glass of water, once a day. The store page lists morning, any time or before bed, with no food instruction. The brand does not print a time to results on the page we read; the 60-day money-back terms below ask for at least nine servings taken, and reviewers describing benefit mention weeks to a few months.

Side effects and who should not take it

The label panel prints no warnings. The store pages say pregnant women should consult their doctor, that people under 18 should consult a healthcare professional, and that in rare cases an unpredictable reaction may happen. Reviewers on ProductReview.com.au report bloating, nausea, cramping and illness, and one reports hives. Chicory fiber can cause gas, and fructans worsened bloating in children with IBS. The product is made from cattle, so it is not suitable for vegans.

What the reviews say

The brand’s U.S. store shows 4.8 from 10,936 reviews (99% would recommend) and its Australian store 4.8 from 8,489, both on a widget the brand hosts. Trustpilot shows 4.3 from 12,986 reviews (71% five-star, 11% one-star), but that score covers the whole company, mostly other products, on a claimed paid profile. The one independent product-level score we read is ProductReview.com.au, 4.5 from 556 reviews, 89% positive, from Australian shoppers, some reviews tagged “Fair Incentive”. The Better Business Bureau lists the company at a B rating, not accredited, with 181 complaints in three years; we could not confirm that its profile for Happy Mammoth LLC of Miami is the same entity as the U.S. store’s Happy Koala LLC. We found no Amazon, Target or Walmart listing.

The recurring praise is less bloating and gas, relief from long-standing gut trouble, and a powder that dissolves and is easy to take daily. The recurring complaints are no effect or more bloating, nausea and cramping, and slow answers on refunds.

The subscription and refund terms

The product page says to “skip, pause, or cancel anytime.” The brand’s terms of service say subscribers have a three-month minimum from the first purchase, and canceling before the third order may bring a fee of $49 or the difference between the one-time and subscription prices on orders already received, whichever is lower. Cancellation must be made in the portal by 11:00 PM the day before billing, or by email at least two days before renewal. A single jar can be bought one time at $69.99.

The refund policy is a 60-day money-back guarantee on the one-jar option, with a bundle refunded for the first month’s supply only. It asks for proof of at least nine servings taken while not drinking alcohol or eating junk food, excludes refunds based on taste, does not accept opened product as a return, and does not allow the same product to be bought again after a guarantee claim. Trustpilot reviewers describe charges without a reminder, difficulty leaving a subscription and a one-hour window to change an order; the company replies to many of them. We could not see whether the early-cancellation fee is enforced in practice.

Who Happy Mammoth Prebiotic Collagen is for

• Someone who wants a collagen powder and a small amount of fiber in one daily glass, and accepts that no trial covers the product.
• Someone who prefers every amount printed on the label, since the actives are not hidden in a blend.
• Someone happy to buy a single jar one time, or to commit to the three-month subscription minimum.

If you want collagen alone, Vital Proteins Collagen Peptides is the plainer comparison, and for fiber without collagen, California Gold Nutrition SunFiber is a fiber-only product. For where to start with bloating, the bloating and gas guide works from the cause.

Cost

One jar is $69.99 for 24 servings, $2.92 a day at one scoop. Two jars are $119.99 and four are $209.99. Subscribe & Save at 15% off is $59.49 a jar ($2.48 a day), or $50.99 each for two jars and $44.62 each for four. Shipping is free on orders of $99 and over. The Australian store sells the same product at A$69.99 a jar.

The products in this catalog

Common questions

Sources

• Abrahams M, O'Grady R, Prawitt J. "Effect of a Daily Collagen Peptide Supplement on Digestive Symptoms in Healthy Women: 2-Phase Mixed Methods Study." JMIR Formative Research, 2022;6(5):e36339. doi.org/10.2196/36339
• Taylor G, Leonard A, Tang JCY, et al. "The effects of collagen peptides on exercise-induced gastrointestinal stress: a randomized, controlled trial." European Journal of Nutrition, 2023;62(2):1027–1039. doi.org/10.1007/s00394-022-03051-2
• Reynolds KM, Hansell EJ, Thorley J, et al. "The effects of collagen peptide supplementation on appetite and post-exercise energy intake in females: a randomised controlled trial." British Journal of Nutrition, 2025;134(4):265–276. doi.org/10.1017/S0007114525103851
• ClinicalTrials.gov NCT06937801: collagen hydrolysate and gastrointestinal symptoms in healthy adults (sponsor Rousselot). clinicaltrials.gov/study/NCT06937801
• Bouhnik Y, Vahedi K, Achour L, et al. "Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans." Journal of Nutrition, 1999;129(1):113–116. doi.org/10.1093/jn/129.1.113
• Olesen M, Gudmand-Hoyer E. "Efficacy, safety, and tolerability of fructooligosaccharides in the treatment of irritable bowel syndrome." American Journal of Clinical Nutrition, 2000;72(6):1570–1575. doi.org/10.1093/ajcn/72.6.1570
• Chumpitazi BP, McMeans AR, Vaughan A, et al. "Fructans Exacerbate Symptoms in a Subset of Children With Irritable Bowel Syndrome." Clinical Gastroenterology and Hepatology, 2018;16(2):219–225. doi.org/10.1016/j.cgh.2017.09.043
• Happy Mammoth U.S. store: label, directions and price. store.happymammoth.com
• Happy Mammoth terms of service and refund policy. store.happymammoth.com/policies/refund-policy
• ProductReview.com.au, Trustpilot and Better Business Bureau profiles: scores, counts and complaint text. productreview.com.au