PepRank

GHK-Cu (topical)

Also: copper tripeptide-1 · copper peptide serum

Supplement

Decades-old cosmetic copper peptide; gentle skin firmness/texture and possibly hair benefits.

Safety tier
Caution
strict bar
Positive
59%
of 44 reports
Per month
≈ €9–36
estimate
Rank
#2
of 23 supplements

At a glance

Access
Supplement
TopicalFelt in 8–12 weeks

Builds over days or weeks of regular use rather than with each dose.

Best effects
Smoother texture, more even tone · less under-eye darkness · scalp/hair support (weak evidence) · post-procedure healing
Downsides
Mild irritation/tingling · blue tint / staining with DIY mixes · do not combine with strong acids or vitamin C at once
Typical use
1-2% serum once or twice daily, often on a hyaluronic base; patch test first.
Stacked with
Stacked with
Red-light therapy: the most-reported pairing; serum applied before or after a mask or panel session. · tretinoin or retinol: commonly used on alternate nights or opposite ends of the day rather than layered. · minoxidil (scalp): hair-loss users apply copper peptide in the morning and minoxidil at night.

Safety

Tier by safety barStrict CautionBalanced CleanEvidence only Clean
  • Seen harm0 of 3
  • Mechanism1 of 3
  • Data gap1 of 3
  • Silent harm1 of 3
  • Product1 of 3
Never if
Wilson disease or copper allergy
Why each score
Seen harm 0/3
Decades of cosmetic use without a published serious reaction or contact-dermatitis case; first-hand reports of lasting skin laxity ('copper uglies') are cosmetic and confounded by acids and retinoids. CIR 2014: tripeptide-1 and copper tripeptide-1 safe at typical use below 10 ppm ↗r/30PlusSkinCare: copper peptide uglies (loose skin months after stopping, with acids and retinol) ↗
Mechanism 1/3
Raises growth factors and remodelling enzymes in wound models; at topical doses systemic exposure is negligible, so any harm path beyond local skin changes is speculative. CIR 2014: tripeptide-1 and copper tripeptide-1 safe at typical use below 10 ppm ↗
Data gap 1/3
CIR found it safe in 2014 at typical use below 10 ppm, but serums sold by percentage are far stronger than anything it assessed; small controlled trials add little. CIR 2014: tripeptide-1 and copper tripeptide-1 safe at typical use below 10 ppm ↗Venous stasis ulcers: 0.4% tripeptide-copper cream no better than vehicle, RCT n=86 (PubMed 1495150) ↗
Silent harm 1/3
Irritation shows at once, but the laxity some describe develops over weeks and may not reverse quickly. r/30PlusSkinCare: copper peptide uglies (loose skin months after stopping, with acids and retinol) ↗
Product 1/3
OTC serums from mainstream brands at concentrations beyond CIR's, plus DIY serums from grey-market powder; CIR notes commercial GHK-Cu can carry mildly neurotoxic impurities. CIR 2014: tripeptide-1 and copper tripeptide-1 safe at typical use below 10 ppm ↗

User reports

All 50 reports →
Users report
Gradual improvements in texture, tone, under-eye darkness and hair (one '2-year serum' post and some 'hair darkened' reports), but enthusiasm is clearly lower than for injections. Experienced users say the two routes do different things. Around 40% see little or end up worse. The most common bad report is the 'copper uglies': duller skin, new fine lines and a saggy look within a few weeks of twice-daily use, which usually clears over one or two skin cycles after stopping and lets many people return at every-other-day use. A few report lasting looseness. Irritation, a metallic smell and blue or orange residue are the smaller gripes.
Glowing 7Positive 20Mixed 4Nothing 7Negative 4Bad reaction 2
  • @mir_btc· · 249 likesOriginal ↗

    Got unbelievable results (and I turn 40 in a month) from 2 months of red light therapy + gelatinous broths and glycine + ghk-cu peptide serum

    GlowingTopical · 2 months

    combined with red light, broths and glycine

  • r/30PlusSkinCare· · 24 upvotesOriginal ↗

    HOLY it is effective at reducing fine lines and pore size. I've been using for two months in the morning and I cannot even believe my skin.

    GlowingBiossance copper peptide serum, mornings · Topical · 2 months

    self-described skincare junkie; Biossance Squalane + Copper Peptide serum

  • r/30PlusSkinCare· · 19 upvotesOriginal ↗

    I started using copper peptides recently in place of tret as my partner and i are trying to have a kid, and so far I haven't noticed much of a difference

    NothingThe Ordinary Buffet + Copper Peptides 1%, nightly · Topical

    swapped in for tretinoin while trying to conceive

Where to buy

All 24 offers →
Getting it
Over-the-counter cosmetic serums (The Ordinary, NIOD, Biossance); DIY serums from GHK-Cu powder.

No listing can be priced, so the researchers estimate ≈ €9–36 a month.

Cheapest from trusted shops in the EU

ShopPackPricePer mgPer monthTesting
Semax PolskaEU · PL
Trust 4/5Each product shows an Analiza Białek (Wrocław) HPLC report naming its operator Dobre Peptydy sp. z o.o. as the client, with a verification password (Semax 60 mg: 62.18 mg, 99%), and Reddit buyers since 2024 report fast, professional deliveries; the only complaints are about felt effect.Ships to France for €14, 1–5 days.COAs ↗
powder · 50 mg€33€0.66/mg—Third-party tested

Studies

Evidence
Small human studies — Cosmetic controlled studies; long cosmetic-use safety record
1 more study and 2 sources

Sources

Molecule

Sequence
GHK
Length
3 amino acids
Modifications
Cu(II) complex

Sequence

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.