Khavinson oral calf-brain peptide extract (Cytomax A-5); one in-house report, no first-hand users found.
Safety tier
Caution
strict bar
Positive
3/10
researcher estimate
Per month
≈ €49–110
estimate
Rank
#20
of 23 supplements
At a glance
Onset
Nothing acute; the developer's report assessed patients at the end of a 10-20 day course.
Lasts
Taken as 10-30 day courses once or twice a year; any claimed benefit is said to persist for months.
Access
Supplement
Best effects
Claimed: better attention, memory and stamina after a 10-20 day course (developer report only) · claimed: fewer headaches and less fatigue in people after brain injury or stroke (developer report only)
Downsides
No measurable effect expected acutely; judged over weeks · cost of repeated 20-60 capsule courses · nobody has shown that intact peptides survive digestion
Typical use
1-2 capsules (10-20 mg peptide complex) two or three times a day before meals for 10-20 days, or 2 capsules a day for 30 days; repeated after 3-6 months (manufacturer).
Stacked with
Stacked with
Pinealon: Sellers pair the extract with the synthetic brain tripeptide, a 'Cytogen then Cytomax' sequence the Khavinson catalogue itself recommends. · Cortexin or Cortagen: Listed together by visual-snow and post-concussion users shopping for brain bioregulators; no outcome was reported.
Safety
Watch
Made from the central nervous tissue of calves (up to 12 months old): bovine brain is the tissue that carried BSE to people, so a prion route is theoretical rather than impossible, though calves under 12 months fall outside the EU specified-risk-material rule · Allergy to bovine proteins
Tier by safety barStrict CautionBalanced CleanEvidence only Clean
Seen harm0 of 3
Mechanism1 of 3
Data gap2 of 3
Silent harm1 of 3
Product1 of 3
Never if
Pregnancy or breastfeeding (no human reproductive data) · Allergy to bovine (beef) proteins · Anyone avoiding bovine nervous tissue on BSE/prion grounds
Why each score
Seen harm 0/3
No serious adverse event has been reported, but the zero reflects how little documented exposure there is (one 48-patient developer report that noted no adverse effects, and no first-hand user reports found), not reassurance. Cerluten institute clinical report (English translation) ↗
Mechanism 1/3
The peptides themselves have no named harm pathway. The one route to serious harm is theoretical: prion contamination of bovine central nervous tissue, the tissue that transmitted BSE to people. It is remote because the source is calves under 12 months, below the EU's specified-risk-material age for bovine brain, so it stays a speculative 1. Regulation (EC) 999/2001 Annex V: specified risk material ↗Peptide Product: Cerluten (brain peptide complex A-5) ↗
Data gap 2/3
A Russian food supplement, not an approved drug anywhere. The only human data are one open, non-randomised report of 48 patients against 37 controls from the developer's clinic, never published in a journal; the Cortexin trials concern an injected extract and do not bridge to oral capsules. Cerluten institute clinical report (English translation) ↗
Silent harm 1/3
Rated on the most plausible harm, an allergic or digestive reaction to a bovine protein extract, which would be noticed and stop with the capsules. The theoretical prion route behind the mechanism score would be silent for years, but at mechanism 1 it does not set this axis.
Small human studies — One open, non-randomised 48-patient report from the developer's own clinic (vs 37 on standard care), never published in a journal; nothing on PubMed names Cerluten. Related evidence is for different products: injected Cortexin and the synthetic Pinealon and Cortagen.
Caveat
Consistent with Pinealon (kept) and unlike Epitalon (excluded): Cerluten makes no telomerase or cell-division claim, so the theoretical harm routes are prion contamination of bovine nervous tissue and allergy, not tumour promotion. The prion route is remote with calves under 12 months, but it is the reason this is not rated clean. Efficacy rests on one unpublished open report from the developer, and nobody has measured intact peptides in blood after an oral capsule.
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.