This guide covers what Retatrutide 20mg is, what the research says, and what separates a verified UK source from an unverified one.
What Is Retatrutide?
Retatrutide (LY3437943) is a synthetic triple-receptor agonist peptide developed by Eli Lilly, currently in Phase 3 clinical trials. It targets three hormone receptor pathways simultaneously — GLP-1, GIP, and glucagon — making it structurally distinct from existing GLP-1 compounds such as semaglutide and tirzepatide.
Phase 2 trial data published in the New England Journal of Medicine showed mean body weight reductions of up to 24% over 48 weeks at the highest dose tested. Phase 3 TRIUMPH trial data is expected through 2026.
Retatrutide is not approved by the MHRA and is not available on prescription in the UK. It is available as a research peptide for laboratory and scientific research purposes only.
Retatrutide 20mg — Vial vs Disposable Pen
Retatrutide 20mg is available in two formats in the UK research market.
Lyophilised Vial
Supplied as a freeze-dried powder requiring reconstitution with bacteriostatic water before use. Offers flexibility in concentration and is the format used in most research protocols.
Sculpt Labs Retatrutide 20mg vial — £70
Disposable Pen
Pre-loaded format that eliminates the reconstitution process. Doses are dialled in directly, removing variables associated with manual measurement.
20mg pen — £90 · 40mg pen — £140
Why Purity Verification Matters
The UK research peptide market has expanded rapidly. Not every vendor operating in this space publishes independent purity verification for their products.
The industry standard for third-party peptide testing is Janoshik Analytical, a Czech laboratory widely regarded as the most rigorous independent tester in the peptide research sector. A Janoshik Certificate of Analysis (COA) confirms compound identity, purity percentage, and batch number — allowing the buyer to verify exactly what they are receiving.
Sculpt Labs publishes Janoshik COAs for every batch on our Purity Reports page. Current Retatrutide batch purity: 99%.
When evaluating any UK Retatrutide source, the questions to ask are:
- Is a third-party COA published openly, or only available on request?
- Does the COA reference a specific batch number matching your order?
- Is the testing laboratory independent — not in-house?
Sculpt Labs Retatrutide 20mg — What's Included
Every Retatrutide order from Sculpt Labs includes:
- Retatrutide 20mg vial or disposable pen, Janoshik verified
- Same-day UK dispatch via Royal Mail Tracked
- Purity report accessible at sculptlabs.uk/purity-reports
- BAC Water available separately for vial reconstitution
UK delivery only. All products are supplied strictly for research and laboratory purposes.
View Retatrutide 20mg →Frequently Asked Questions
Is Retatrutide legal in the UK?
Retatrutide is not a controlled substance under the Misuse of Drugs Act 1971 in the UK. It is available as a research peptide for laboratory use. It is not licensed by the MHRA for human use.
What purity should Retatrutide be?
Independent testing should confirm purity of 98% or above via HPLC analysis. Sculpt Labs Retatrutide tests at 99% purity per current Janoshik batch report.
What is the difference between a vial and a pen?
A lyophilised vial requires reconstitution with bacteriostatic water before use. A disposable pen comes pre-loaded and does not require reconstitution. Both contain the same research-grade compound.
Does Sculpt Labs ship same day?
Yes. Orders placed before 2pm Monday to Friday are dispatched same day via Royal Mail Tracked.
⚠ All products are for research and laboratory purposes only. Not for human consumption.