The Peptide Guide now covers seventeen compounds. This week we added Tesamorelin, the peptide with the most published human clinical data of anything in...
PepiScreen Blog · Guide Update
Tesamorelin and GHK-Cu, added to the Peptide Guide
Two more entries in our reference guide — one a decade-old FDA-approved GHRH analogue, one a naturally-occurring copper peptide. Here is what each is, why we added it, and the specific things to check on the COA before you buy a vial.
Published 15 August 2026 · By PepiScreen editorial · 4 min read · Educational, not medical advice
The Peptide Guide now covers seventeen compounds. This week we added Tesamorelin — the peptide with the most published human clinical data of anything in the growth-hormone family — and GHK-Cu, the copper-bound tripeptide that dominates cosmetic skincare and shows up increasingly in injection protocols for hair and wound healing. Both were already circulating in the market, and both were already covered in our supplier audits. Adding them to the public guide makes the reference complete.
The rest of this post walks through each one — what it is in plain language, what people are actually using it for, and the practical purity questions we look at when a supplier claims to sell it.
Jump to
Peptide 1 of 2 · Therapeutic
Tesamorelin
A stabilised analogue of endogenous growth-hormone-releasing hormone. FDA-approved in 2010 for HIV-associated lipodystrophy, and one of the very few peptides on our list with a real Phase III human trial behind it.
What people use it for
Visceral (deep abdominal) fat reduction, improved lipid profile, and preservation of lean mass. Off-label interest comes from people who want the metabolic effects of higher endogenous GH without pinning synthetic GH itself. Tesamorelin has more published human data than sermorelin, CJC-1295 and ipamorelin combined — but that data is still overwhelmingly in HIV lipodystrophy patients, not in healthy adults using it for body composition.
The COA for Tesamorelin needs a mass-spec confirmed molecular weight of ~5,196 Da. If the supplier only cites HPLC purity, the chromatogram peak can hide a truncated 43-mer that a customer will never notice.
What to check when buying
Tesamorelin is a 44-amino-acid peptide, so it costs more to manufacture cleanly than shorter peptides — a supplier quoting suspiciously close to BPC-157 pricing is a flag. Look for mass-spec confirmation with a chromatogram attached, not just a purity number. Our audit rejects Tesamorelin COAs missing the mass-spec confirmation because peptide length is one of the easiest places to short-change a customer without them ever noticing.
Peptide 2 of 2 · Research chemical
GHK-Cu
A copper-bound tripeptide (glycyl-histidyl-lysine plus a copper ion) that occurs naturally in human plasma. Concentration declines with age. Cosmetic use is topical serums and creams; the injection form is what shows up in supplier catalogues.
What people use it for
Topically: skin regeneration, wrinkle reduction, and hair-follicle stimulation — this is where the bulk of published research sits, and where cosmetic dermatology has quietly used GHK-Cu for two decades. By injection (subcutaneous or intramuscular): the same skin effects plus wound-healing and connective-tissue repair. Injection use is off-label and jurisdictionally research-chemical.
Real GHK-Cu is genuinely, physically blue in solution because of the copper ion. A colourless vial photo on a supplier COA is a warning sign — they have shipped uncomplexed GHK, or a placeholder.
What to check when buying
Beyond the colour test, our audit checks the copper content is stated separately from the peptide mass, that mass-spec fragments match glycine-histidine-lysine, and that storage instructions specify refrigeration — copper-peptide solutions oxidise if held at room temperature for weeks.
Side-by-side
The two, compared
| Tesamorelin | GHK-Cu | |
|---|---|---|
| Regulatory status | Therapeutic · FDA-approved 2010 | Research chemical (injection) · cosmetic (topical) |
| Length | 44 amino acids · ~5,196 Da | 3 amino acids + Cu · ~340 Da |
| Route | Subcutaneous injection | Topical (mainstream) or subcutaneous |
| Colour of solution | Clear | Blue — always |
| Primary COA red flag | No mass-spec confirmation of 5,196 Da MW | Colourless vial photo, or no separate copper content |
| Human trial data | Extensive (Phase III+ in HIV lipodystrophy) | Extensive topical, sparse for injection |
Shortlisting a supplier for these?
The Peptide Guide is a reference — it describes what each compound is, what people report, and what documented risks the literature calls out. It does not tell you whether any specific supplier’s version is real. That is what our Supplier Directory and audit reports are for. If you are shortlisting a supplier for either of these two peptides, check the directory first — we have already looked at their COAs, their lab, their batch history and their price against regional benchmarks.
Related reading
How the audit works →
27 evidence checks per supplier: 12 identity fields, 12 cross-corpus fraud signals, 3 community overlays.
Guide to Using Peptides →
Companion piece on protocol safety, dosing conventions, and when to involve a doctor.
Find a prescriber →
Doctors and clinics who prescribe peptides legally in AU, US, and other jurisdictions.
Educational, not medical advice. PepiScreen is an analytical tool that checks peptide providers on purity, proofs and price. Nothing in this post constitutes medical advice, a diagnosis, a treatment recommendation, or an endorsement of any product or supplier. Speak to a qualified medical practitioner before starting, changing, or stopping any peptide protocol. Australians: refer to the TGA for the current regulatory position on any specific compound.
Get the free Peptide Market History Guide. A 12-page independent guide to the peptide market — how it evolved, the regulatory landscape, and how to read a Certificate of Analysis with a critical eye.
Send me the guide →