Encyclopedia entry
Peptide therapy vs GLP-1 medications
Oliver Mackman · Editorial director · Best Business Loans Ltd (16833937)
Last updated 2026-06-04
Peptide therapy and GLP-1 medications are often confused because both involve peptide molecules given by injection, but they sit in completely different regulatory categories. GLP-1 medications such as semaglutide and tirzepatide are MHRA-licensed prescription medicines backed by large randomised trials. The peptides marketed as "peptide therapy" by private clinics, such as BPC-157, ipamorelin and CJC-1295, are sold under research-use-only wording and hold no UK marketing authorisation for human therapeutic use. They are not the same thing.
The core difference: regulatory status
- GLP-1 medications: licensed prescription-only medicines (POM). They have UK marketing authorisations, published phase-3 trial evidence, and are supplied by a prescriber through a clinic, pharmacy or the NHS.
- "Peptide therapy" peptides: sold research use only. For most of these peptides there is no UK marketing authorisation for human therapeutic use, and no published human randomised controlled trials for the marketed uses. The "research use only" wording is what allows them to be sold, and it does not authorise human treatment.
What each term actually covers
- · GLP-1 medications: semaglutide (Wegovy, Ozempic), tirzepatide (Mounjaro), liraglutide. Indicated for weight management or type 2 diabetes.
- · Peptide therapy (a clinic marketing term): research peptides such as BPC-157, TB-500, ipamorelin, CJC-1295, sermorelin and GHK-Cu, marketed around recovery, growth-hormone support or anti-ageing. There is no single defined treatment called "peptide therapy".
Evidence base
GLP-1 medications have a large body of human randomised trial evidence (the SURMOUNT and STEP programmes). The research peptides sold as peptide therapy have mostly preclinical and animal-model literature, with no human RCTs published for most of the marketed uses. PeptideClear reports the regulatory and evidence position; we do not make efficacy claims for research peptides.
Peptide therapy vs GLP-1 medications at a glance
| Feature | GLP-1 medications | "Peptide therapy" peptides |
|---|---|---|
| UK regulatory status | MHRA-licensed prescription-only medicines | No UK marketing authorisation for human therapeutic use; sold research use only |
| Examples | Semaglutide (Wegovy, Ozempic), tirzepatide (Mounjaro), liraglutide | BPC-157, TB-500, ipamorelin, CJC-1295, sermorelin, GHK-Cu |
| Evidence base | Large human randomised trials (SURMOUNT, STEP) | Mostly preclinical and animal-model; no human RCTs for most marketed uses |
| How accessed in the UK | On prescription via the NHS or a regulated clinic or pharmacy | Private clinics under research-use-only framing; not on the NHS |
| Who decides suitability | A prescriber | No licensed therapeutic use to prescribe for |
How each is accessed in the UK
- · GLP-1: on prescription, through the NHS (Tier 3 weight management) or a regulated UK clinic or pharmacy. A prescriber decides whether it is appropriate.
- · Peptide therapy: through private clinics, sold under research-use-only framing. It is not available on the NHS.
"Peptide therapy for weight loss": which is it?
This is where the confusion concentrates. GLP-1 medications are themselves peptides, so when people search "peptide therapy for weight loss" they almost always mean a licensed GLP-1 medicine. Some clinics use "peptide therapy" loosely as an umbrella that includes GLP-1. If weight loss is the goal, the licensed, evidence-backed route is a GLP-1 medication, and whether it is appropriate is a decision for your prescriber.
Related: What is peptide therapy · MHRA medicines classification · "Research use only" framing · Research peptides.