I wished I had better pictures but I definitely see an improvement. It looks like I have more baby hairs but actually I think they are my existing hair but just thicker.
PositiveTopical · perimenopausal shedding
Late-40s woman, 10 weeks of The Ordinary Multi-Peptide Serum for Hair Density 3-4 days a week.
I saw rave reviews but have to be honest it did nothing for me:/
NothingTopical · thinning hair
One bottle of The Ordinary Multi-Peptide Serum for Hair Density, almost daily; hair worse overall, which she puts down to stress.
Users report
Almost all first-hand data is for multi-active serums, chiefly The Ordinary Multi-Peptide Serum (biotinoyl tripeptide-1 and acetyl tetrapeptide-3 alongside Redensyl, Baicapil, AnaGain and caffeine), so no single peptide can be credited. About 40% report real gains: baby hairs at temples and edges or less shedding after 2-6 months, best in shedding (telogen effluvium), traction or post-damage hair. They fade within 1-2 months of stopping. As many see nothing beyond a fluffier, 'plumped' feel, even after a year or two. A minority get itch, flaking on natural hair, or a shed. Two report headaches or palpitations, plausibly from the caffeine in the formula. Felt nothing: ~20% felt nothing; another ~20% mixed (cosmetic thickening only).
Best effects
Less shedding · baby hairs at temples, edges and hairline after 2-6 months · hair looks and feels thicker (partly cosmetic coating) · calmer, less itchy scalp for some
Downsides
Scalp itch or irritation · flaking/white residue, sticky or greasy feel · early shed reported by a minority · gains lost within 1-2 months of stopping · headache or palpitations in a few (formula contains caffeine)
Evidence
Small human studies — small industry-run trials of the cosmetic complexes (Capixyl placebo-controlled n=30; RCP vs minoxidil open comparison); no independent trial of biotinoyl tripeptide-1 alone
Caveat
Biotinoyl tripeptide-1 is biotin bound to GHK (without copper); its anti-5-alpha-reductase and anchoring claims come from supplier (Sederma) in-vitro data. Public evidence is two small industry-adjacent trials of blends, and Reddit reports are of blends, so the score is for 'peptide hair serums', not the molecule. Acetyl tetrapeptide-3 (Capixyl) had too few standalone reports for its own entry and is folded in here. No harm path found; the palpitation/headache reports fit the caffeine in The Ordinary's formula and resolved on stopping.
Typical use
A few drops to 1 ml leave-on to the scalp once daily (The Ordinary), or a 3-5% Procapil spray once or twice daily; judge after 3-6 months.
Getting it
Over-the-counter cosmetic: The Ordinary Multi-Peptide Serum for Hair Density (~€20/60 ml), many RCP/Procapil sprays (3-5%) and shampoos, especially in India and Turkey.
Stacked with
Minoxidil: commonly layered at a different time of day; users who credit it most often already use minoxidil or spironolactone · Microneedling: frequently paired; adds its own effect · Ketoconazole shampoo: helps the itch/flaking some get from the serum
I wished I had better pictures but I definitely see an improvement. It looks like I have more baby hairs but actually I think they are my existing hair but just thicker.
PositiveTopical · perimenopausal shedding
Late-40s woman, 10 weeks of The Ordinary Multi-Peptide Serum for Hair Density 3-4 days a week.
Works for me, but I use it almost daily! Took a good 3 months of consistent use to start noticing. My temples filled in and I started sprouting lots of baby hairs.
PositiveTopical · temple thinning
The Ordinary Multi-Peptide Serum for Hair Density almost daily.
I ran a little experiment with it where I was on it for 6 months, then off for 6 and now I am back on for 2. I can conclude that personally it helped me tremendously in the 6 months that I used it
PositiveTopical · male pattern hair loss
On/off experiment with The Ordinary Multi-Peptide Serum for Hair Density (6 months on, 6 off, back on) alongside finasteride.
I used a spray that contains %3 procapil for like 5 months. Results weren't unreal but it thickened up my hairline and my friend also noticed the regrowth but then i stopped using it and all gains lost in like one-two months
I've been the Ordinary serum for the past few weeks. Can't speak to regrowth yet but I have definitely noticed less hair shedding.
PositiveTopical · hair fall
A few weeks of The Ordinary Multi-Peptide Serum for Hair Density added to spironolactone 50 mg and 5% minoxidil, which had not controlled the shedding.
my hair is twice if not 3x more dense and full. Where my temples used to thin/bald is now full of baby hairs and growing sections
PositiveTopical · recovery from extension and bleach damage
A year of The Ordinary Multi-Peptide Serum for Hair Density after removing extensions and stopping bleaching, which also explains much of the recovery.
I feel like it almost instantly made my hair feel thicker and healthier but I don’t know that it ever did much in terms of regrowth. Used for maybe 4 months
MixedTopical · male pattern hair loss
About 4 months of The Ordinary Multi-Peptide Serum for Hair Density.
I feel as though my hair loss has visibly progressed since using it, a bit quicker than it has been, however, it hasn’t caused any irritation or redness or anything. I’m on week 10 of daily use.
NegativeTopical · female hair loss
3 bottles / ~12 weeks of The Ordinary Multi-Peptide Serum for Hair Density daily with scalp massage and pumpkin seed oil; stopped after itch and spots.
But i noticed after 3 weeks that i had started to lose more hair than usual, in the shower i would usually lose 5-10 hairs but after the serum i started losing 30+.
NegativeTopical · hair fall
2-3 weeks of The Ordinary Multi-Peptide Serum for Hair Density together with Kérastase Genesis serum.
about two hours after i started to experience rapid/irregular heartbeat, very bad dizziness, and veins dilating back and fourth.
Bad reactiona full dropper (label says a few drops) · Topical · hair thickening
Second day of The Ordinary Multi-Peptide Serum for Hair Density at a large dose; had a similar reaction to a pre-workout, so caffeine or vasodilator sensitivity is the likely cause.
Safety
Tier by safety barStrict CautionBalanced CleanEvidence only Clean
Each bead is one amino acid in the peptide's chain, coloured by its side chain: grey for non-polar, cyan for polar, blue for positively charged and fuchsia for negatively charged. Length and mix tell related peptides apart at a glance, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4. The colours describe chemistry only and predict neither effect nor safety.
non-polarpolarpositivenegative
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. Kept peptides rank by the same reports' mean grade, shrunk the same way, and excluded ones follow in that order.
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 alongside the computed scores until reports arrive.
Safety tier
Each peptide is tiered clean, caution or excluded from its five risk axes under the chosen safety bar. An excluded peptide has a plausible route to serious harm, 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 exclude a peptide. 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.
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.
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.