UK · Independent · No vendors, no dosing, no hype
What's that peptide?
The honest, UK guide to research peptides. What each one actually is, whether it works, whether it's legal here in the UK, and what's just hype. We grade every one by how much we really know in humans. We don't sell anything, and we take no money from sellers.
- 66
- Peptides
- 9
- Stacks decoded
- 286+
- Cited sources
- £0
- From sellers
The evidence scale
How we grade →Approved
Promising
Early
Animal only
Harm / none
01 / The problem
Two worlds, one word.
Some peptides are licensed medicines, tested in large human trials. Most of the ones you read about online are research chemicals. They have been studied mostly in animals. They are not approved for people, and they sell in a legal grey area. We keep the two clearly apart.
02 / The method
We grade by one question.
How much do we actually know in humans? Every peptide gets a single grade. It runs from A, an approved medicine with strong human trials, down to F, negligible evidence or known harm. One letter shows you how solid the ground is.
Most searched
All 66 →Weight & Metabolic
Semaglutide
A licensed prescription medicine that mimics a gut hormone to suppress appetite, improve blood sugar, and reliably produce weight loss.
Grade A · Approved medicine or robust human trials.
Read entryWeight & Metabolic
Tirzepatide
A prescription injection that mimics two gut hormones at once to reduce appetite, lower blood sugar and drive substantial weight loss.
Grade A · Approved medicine or robust human trials.
Read entryWeight & Metabolic
Retatrutide
An experimental once-weekly injectable that hits three metabolic hormone receptors at once and has produced the largest trial weight-loss results seen so far. It is not yet an approved medicine.
Grade B · Human trials exist but are incomplete.
Read entryRecovery & Repair
BPC-157
A lab-made peptide based on a fragment of a protein found in stomach fluid, widely studied in animals for tissue repair but essentially untested in humans.
Grade D · No meaningful human evidence yet.
Read entryGrowth Hormone
MK-677 (Ibutamoren)
A growth-hormone-boosting pill that genuinely raises IGF-1 and adds a little lean mass, but in every completed trial it failed to make people stronger, healthier or better-functioning. Its maker abandoned it.
Grade B · Human trials exist but are incomplete.
Read entrySkin & Aesthetics
Melanotan II
An unlicensed injectable peptide that darkens skin without sun exposure, sold illegally in the UK and linked to nausea, prolonged erections and worrying changes in moles.
Grade C · Some human data, far from settled.
Read entryThe hyped combos, graded
All stacks →You've heard the names — the Wolverine stack, the GH stack. Here's what's actually in them, and the honest grade for every peptide inside.
CJC-1295 + Ipamorelin
2The most-marketed growth-hormone peptide combo: CJC-1295 (a GHRH analogue) plus ipamorelin (a selective GHRP), run together to nudge the pituitary into releasing more growth hormone. Both are Grade C — there's some early human data on each one separately, but no proper trial of the pair, despite the clinics selling it as an anti-ageing and fat-loss certainty.
Break it downRetatrutide + Cagrilintide
4A nickname for pairing a next-gen weight-loss injectable (retatrutide or semaglutide) with the amylin analogue cagrilintide, marketed as the "Ozempic killer" stack. The semaglutide+cagrilintide version (CagriSema) has real Phase 3 human data; the retatrutide+cagrilintide combo people actually buy on the grey market has never been tested together in humans.
Break it downThe Wolverine Stack
2A nickname for running two tissue-repair peptides together, BPC-157 and TB-500, marketed in biohacker and 'recovery' clinics for healing injuries faster. Both are Grade D: the healing story is almost entirely from animals.
Break it downBy what they're studied for
9 areas