Also: first milk · ARMRA / Cowboy Colostrum / WonderCow · goat or sheep colostrum
SupplementImmuneOral
Cow's first milk: immunoglobulins, lactoferrin and growth-factor peptides for gut lining and fewer colds.
Safety tier
Caution
strict bar
Positive
47%
of 24 reports
Per month
≈ €28–56
by mouth
Rank
#12
of 23 supplements
At a glance
Access
Supplement
OralFelt in 2 days – 2 weeks
15 min1 h6 h1 day1 week
Builds over days or weeks of regular use rather than with each dose.
Best 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
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.
Stacked with
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
Safety
Watch
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
Tier by safety barStrict CautionBalanced CautionEvidence only Caution
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.
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.
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.
GlowingSkin & hair · Oral · 2 weeks
unnamed chronic skin condition unresponsive to prescribed treatments
I took it a few years ago and it did not do anything heroic or even noticeable. I had been optimistic about it because it sounded potent and promising once I read what it was...
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.
A month at 1–2 g/day costs ≈ €28–56 from Supersmart at €0.93/g.
Cheapest from trusted shops in the EU
Shop
Pack
Price
Per mg
Per month
Testing
SupersmartEU · LUTrust 4/5Long-established Luxembourg supplement brand selling under EU food-supplement rules with French-language support and per-batch certificates from its contract manufacturer; Reddit has little discussion and no complaints.Ships to France for €6.00, free over €70, 2–4 days.COAs ↗
capsules · 30000 mg
€28
€0.93/g
≈ €28–56 a month
Own COA
Studies
Evidence
Human RCTs — Gut permeability under NSAIDs and heavy exercise, upper-respiratory symptoms in athletes; a meta-analysis of 5 small, mostly biased trials
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.
The peptide's chain of amino acids from its start (the N-terminus) to its end, one bead and one letter for each: A alanine, C cysteine, D aspartic acid, E glutamic acid, F phenylalanine, G glycine, H histidine, I isoleucine, K lysine, L leucine, M methionine, N asparagine, P proline, Q glutamine, R arginine, S serine, T threonine, V valine, W tryptophan, Y tyrosine. A modification such as an N-acetyl cap or a C-terminal amide changes how long it lasts in the body. Length tells related peptides apart, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4, and predicts neither effect nor safety.
Report grades
Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.
GlowingPositiveMixedNothingNegativeBad reaction
% positive
The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Peptides rank by this figure, those with no graded report yet after those with one, and Avoid ones after every other entry.
Researcher estimate
No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks after every peptide with graded reports until its own arrive.
Safety tier
Each peptide is tiered Clean, Caution or Avoid from its five risk axes under the chosen safety bar. An Avoid peptide carries a real risk of harm, a plausible route to serious harm rather than mere unpleasantness, so it stays listed with the reason but ranks behind every other entry, however good its reviews.
Safety bar
The safety bar sets how much risk it takes to rate a peptide Avoid. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.
Seen harm
Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.
Mechanism
A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.
Data gap
How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.
Silent harm
Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.
Product
The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin; taken by mouth or in the nose, a pack avoids the injection risks.
Evidence
The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.
Access
How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.
Price per month
Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.
Dose users report
The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.
Shop trust
Each shop's trust on a 1–5 scale, read from its testing and its reputation: 1 for serious red flags (fabricated COAs, scam reports, impersonation, a closed shop), 2 for no public testing, a new shop or active complaints such as seized parcels, 3 for its own COAs or a short track record, 4 for verified third-party testing or a strong reputation, and 5 for third-party batch reports that name the shop, with years of good independent reputation. A shop without a score counts third-party batch testing as 4, its own COAs as 3 and no public tests as 2.
Best value
Within a category or a goal, a peptide that no other beats on both counts: none is rated more positively for the same or a lower monthly price, and none costs less for the same or a higher rating. The chart joins these into the best-value line; the cheapest of them and the best-rated of them both make it, so the line spans the trade-off from cheap to best. Avoid entries never count, and a peptide needs both a % positive and a price to be compared.
Testing
Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.
Added peptide
Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.