Recovery & Tissue Repair Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. None of the research peptides discussed are licensed medicines in the UK, and no established human dosing exists for any of them.
Peptides marketed for "recovery" — accelerated healing of tendons, ligaments, muscle, and gut tissue — are among the most discussed compounds in fitness and biohacking communities. The interest is understandable: soft-tissue injuries heal slowly, conventional options are limited, and animal studies on these compounds report striking results. The claims circulating online, however, run far ahead of the human evidence, which for the flagship compounds in this category is close to non-existent.
Fat Loss & Metabolic Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. Licensed GLP-1 medicines are available only via prescription through regulated healthcare channels; research-grade versions are not those medicines. No established human dosing exists for the unlicensed compounds discussed.
"Fat loss peptides" is a category that spans two completely different evidence worlds. At one end sit the GLP-1 receptor agonists — semaglutide, tirzepatide — which are licensed medicines backed by some of the largest and most rigorous trial programmes in modern pharmacology. At the other end sit growth hormone secretagogues and fragment peptides sold in the grey market, most of which have thin or failed human evidence. Marketing routinely blurs the two, borrowing the credibility of the licensed drugs to sell the unlicensed ones. This review keeps them separate, because the evidence does.
Muscle & Performance Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. None of the research peptides discussed are licensed for muscle or performance enhancement in the UK, and no established human dosing exists for those uses.
The muscle-building peptide market sells a simple story: stimulate your own growth hormone axis, or supply growth factors directly, and gain the benefits of GH or IGF-1 without "synthetic hormones." The scientific record tells a more awkward one. GH itself is a modest and side-effect-prone muscle agent in healthy adults; the secretagogues that mimic its release have never demonstrated meaningful hypertrophy in a controlled human trial; and the growth-factor and myostatin-pathway compounds either have no human data at all or were halted in trials for safety reasons.
Longevity & Cellular Health Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. None of the compounds discussed are licensed in the UK for longevity or anti-ageing use, and no established human dosing exists for those uses.
Longevity peptides occupy the widest gap between claim size and evidence quality anywhere in the peptide market. The claims are the largest possible — extended lifespan, telomere restoration, mitochondrial rejuvenation — and the supporting human evidence ranges from small, methodologically weak studies out of a single research lineage to none at all. This category also illustrates a recurring pattern: a legitimate, interesting research field (mitochondrial-derived peptides, immunomodulatory thymic peptides) feeding a consumer market that treats early findings as established therapy.
Cognitive & Sleep Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. None of the compounds discussed are licensed in the UK, and no established human dosing exists for cognitive-enhancement use.
The nootropic peptide market is built largely on compounds developed and approved in Russia and the former Soviet sphere — Semax, Selank, Cerebrolysin — plus one genuinely mysterious 1970s discovery (DSIP). The recurring evidence problem here is jurisdictional: these compounds hold approvals and clinical histories in regulatory systems whose evidentiary standards differ substantially from the MHRA, EMA, or FDA, and almost none of that evidence has been replicated in Western trials. "Approved in Russia" is a real fact that tells you much less than marketing implies.
Sexual Health & Hormonal Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. Where licensed medicines exist in this category, they are prescription-only and jurisdiction-specific.
Sexual-health peptides are unusual in this series: the flagship compound, bremelanotide, actually completed full clinical development and won FDA approval — making it one of the few grey-market peptides with a real, regulator-assessed evidence file. That file is worth reading closely, because it shows both what the compound genuinely does and how modest that is compared to its online reputation. The rest of the category — kisspeptin, gonadotropin-axis peptides, oxytocin — is legitimate endocrinology being retailed ahead of its evidence.
Skin, Hair & Cosmetic Peptides: What the Research Shows
An evidence review. This article is educational only. It does not recommend, endorse, or provide guidance for the use of any compound. Injectable tanning peptides are unlicensed in the UK and carry specific MHRA warnings.
The cosmetic peptide category contains the full evidence spectrum in one place: a licensed medicine (afamelanotide) with a narrow, legitimate indication; topical cosmetic peptides with modest but real trial support; oral collagen peptides with a growing consumer-grade evidence base; and an injectable grey-market tanning peptide (melanotan II) that regulators have been warning about for over a decade. Because these compounds share chemistry and naming, marketing constantly blurs them — the licensed drug's existence is used to imply the grey-market analogue is safe.