# Bovine colostrum

Cow's first milk: immunoglobulins, lactoferrin and growth-factor peptides for gut lining and fewer colds.

- Page: https://peprank.xyz/peptides/bovine-colostrum
- Category: Gut (Supplement)
- Also known as: first milk; ARMRA / Cowboy Colostrum / WonderCow; goat or sheep colostrum
- Routes: Oral
- Safety tier: Strict: Caution · Balanced: Caution · Evidence only: Caution
- Risk axes (0 none to 3 severe): Seen harm 1, Mechanism 1, Data gap 1, Silent harm 1, Product 0
- Positive: 47% of 24 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #12 of 23 supplements
- Graded reports: 24 (Glowing 7, Positive 4, Mixed 3, Nothing 4, Negative 2, Bad reaction 4)
- Evidence: Human RCTs — Gut permeability under NSAIDs and heavy exercise, upper-respiratory symptoms in athletes; a meta-analysis of 5 small, mostly biased trials
- Access: Supplement
- Onset: Gut changes within days to 2 weeks in responders; immune effects judged over a season.
- Lasts: Taken daily; benefit lasts while taking it and fades after stopping, or after 1-2 months for some.
- Cost per month: ≈ €11–23 (at 1–2 g/day, iHerb at €0.38/g)
- Updated: 2026-10-30

## What users report

Loud fans in r/SIBO, r/ibs and r/Gastritis: firmer, normal stools after years of IBS-D, less bloating, coming off acid blockers, and long-term users with low IgG who say they stopped catching colds. Gains often appear within days but in several reports fade after one to two months. About a fifth notice nothing after months, even on expensive brands, and a similar share report reactions: hives or itching that returned on rechallenge, bloating and gas (lactose), constipation, and a recurring 'unexplained weight gain' thread. The category is heavily marketed (ARMRA, influencer brands), so glowing branded posts deserve some scepticism. Felt nothing: ~15-20% of reports.

**Effects:** normal, firmer stools in IBS-D; less bloating and stomach upset; fewer colds / upper-respiratory infections; faster workout recovery (some); less hair shedding (some)

**Downsides:** bloating, gas, constipation (lactose and dairy protein); itchy rash or hives in a minority; unexplained weight gain / puffiness reported by several users; benefit fades after 1-2 months for some; expensive premium brands

**Risks:** dairy-protein allergy: hives that recur on rechallenge and one report of airway swelling; contraindicated in milk allergy; contains IGF-1: one small trial found a rise in serum IGF-1, a larger dose in another found none; a theoretical growth-factor concern that has not been confirmed at supplement doses

**Caveat:** Kept as mostly-clean: it is a food (the first milk of a cow) with a long record of safe use, and the IGF-1 worry rests on one 9-person trial that a larger dose failed to reproduce, against ordinary dairy's own IGF-1 content. The real exposures are allergy to bovine proteins, where hives that return on rechallenge mean stopping, and lactose. Reddit's weight-gain and liver-enzyme reports are single anecdotes without a mechanism. The trial evidence comes largely from one group (Playford and Marchbank), and the athlete trials are small.

**Typical use:** 1-2 g/day in capsules (studies used up to 20-60 g/day of powder), on an empty stomach or with a meal; avoid hot drinks; start low if lactose-sensitive.

**Getting it:** Widely sold as capsules and powder; cheap commodity capsules (NOW, California Gold) and premium marketed powders (ARMRA) contain the same class of product. Lactose and IgG content vary by brand.

**Stacked with:** zinc carnosine (polaprezinc) (combined in the Davison 2016 exercise gut-permeability trial, with an additive effect); lactoferrin (often added by SIBO and IBS users; it is one of colostrum's own active proteins); lactase (lactose-intolerant users take it with lactase to reduce gas)

## Risk profile

- **Seen harm 1/3:** No serious events in the small RCTs; first-hand reports include airway swelling (in someone without known milk allergy) and raised liver enzymes after a second month, isolated and unverified. Anaphylaxis in milk allergy is a contraindication.
- **Mechanism 1/3:** Contains IGF-1, but at supplement doses most studies, including 60 g/day for four weeks, found no rise in serum IGF-1, so the growth-factor concern is weak.
- **Data gap 1/3:** A traditional food with long supplement use, but the RCTs are small (a five-trial meta-analysis of 152 people) and largely from one group, with no formal safety assessment.
- **Silent harm 1/3:** Allergic and GI reactions appear within days; the isolated liver-enzyme report would show only on a blood test.
- **Product 0/3:** OTC capsules and powders taken orally, from commodity to premium brands.
- **Never if:** Cow's milk allergy; Lactose intolerance (most products contain lactose); Competitive athletes (WADA advises against it)

## Top reports

- Glowing, gut: “I could cry tears of joy, I never thought I’d feel like this again, like my body can move and I can eat without immense discomfort. My body looks so much younger and stronger than it’s been in years. I’ve only been taking it for a couple weeks.” — [r/SIBO](https://www.reddit.com/r/SIBO/comments/mv5hza/do_yourself_a_favor_and_try_out_colostrum/)
- Glowing, skin-hair: “Colostrum cured a skin disease which i was suffering from for more than a decade. Ive had countless of doctor visits, blood tests, skin samples, tried different medications which either did nothing or helped temporarily. I took colostrum for 2 weeks and my skin completely healed.” — [r/SIBO](https://www.reddit.com/r/SIBO/comments/136kyxc/huge_benefit_from_colostrum/jn68csk/)
- Glowing, gut, one dose a day: “Since starting colostrum, I haven’t needed Nexium, Pepcid, or any other supplements. I’ve even tested it with known triggers like pasta sauce and hot sauce, and had no issues.” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/1l975qo/colustrum_for_the_win_back_to_wings_and_pizza/)
- Glowing, gut, 500 mg morning and night on an empty stomach: “It was the only thing that helped with bloating and improved my digestion dramatically. I took morning/night on empty stomach...500mg” — [r/Biohackers](https://www.reddit.com/r/Biohackers/comments/17xofcb/how_did_colostrum_supplementation_affect_you/k9scy6y/)
- Glowing, immune: “I have been taking it for 5 years. I always had low igg levels and used to get sick daily. However, ever since taking it, I’m the only one among friends and family who hasn’t been sick in years.” — [r/Supplements](https://www.reddit.com/r/Supplements/comments/1iv2wln/colostrum_marketing_hoax_or_miracle_powder/mebk6z1/)

## Cheapest in Europe

- [Supersmart](https://www.supersmart.com/fr/boutique/systeme-immunitaire/colostrum-complement-0703) (LU): Colostrum 500 mg (30% IgG), 60 gastro-resistant capsules, €28, €0.93/g

## Studies

- [Jones et al., Bovine colostrum and upper respiratory symptoms during exercise training: systematic review and meta-analysis of RCTs (BMC Sports Sci Med Rehabil 2016)](https://link.springer.com/article/10.1186/s13102-016-0047-8) (meta-analysis, n=152, 2016): Over 8-12 weeks colostrum cut the rate of upper-respiratory symptom days by 44% and episodes by 38% vs placebo; four of five trials at moderate or high risk of bias.
- [Marchbank et al., Bovine colostrum truncates the increase in gut permeability caused by heavy exercise in athletes (Am J Physiol GI 2011)](https://pubmed.ncbi.nlm.nih.gov/21148400/) (rct, n=12, 2011): Crossover: after 14 days of colostrum the 2.5-fold rise in gut permeability after heavy exercise was cut by 80% vs placebo.
- [Davison et al., Zinc carnosine works with bovine colostrum in truncating exercise-induced gut permeability (AJCN 2016)](https://pubmed.ncbi.nlm.nih.gov/27357095/) (rct, n=8, 2016): Four-arm crossover: colostrum or zinc carnosine each cut the threefold exercise-induced permeability rise by about 70% after 14 days; combined they worked sooner.
- [Playford et al., Bovine colostrum reduces the NSAID-induced increase in intestinal permeability (Clin Sci 2001)](https://pubmed.ncbi.nlm.nih.gov/11352778/) (controlled, n=7, 2001): Crossover in healthy men: colostrum prevented the threefold permeability rise from 5 days of indomethacin; no effect in 15 patients already on long-term NSAIDs.
- [Kuipers et al., Effects of oral bovine colostrum supplementation on serum IGF-I levels (Nutrition 2002)](https://pubmed.ncbi.nlm.nih.gov/12093430/) (open-label, n=9, 2002): 60 g/day for 4 weeks did not change serum IGF-1 or IGFBP-3 and produced no positive doping tests.
- [Mero et al., Effects of bovine colostrum supplementation on serum IGF-I, IgG, hormone and saliva IgA during training (J Appl Physiol 1997)](https://pubmed.ncbi.nlm.nih.gov/9338422/) (rct, n=9, 1997): 8-day crossover in sprinters: serum IGF-1 rose more on colostrum than on whey placebo; IgG and saliva IgA unchanged.

## Sources

- [Playford & Weiser, Bovine colostrum: its constituents and uses (Nutrients 2021; authors affiliated with colostrum maker PanTheryx)](https://www.mdpi.com/2072-6643/13/1/265)