What Is PT-141 (Bremelanotide)? A Research Primer
PT-141, also called bremelanotide, is a synthetic cyclic peptide in the melanocortin-receptor agonist class. Sold for laboratory research use only.
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide derived from the melanocortin agonist Melanotan II. Where Melanotan II acts broadly across melanocortin receptors, PT-141 is more selective for the MC3R and MC4R receptor subtypes. It is sold strictly as a research-use-only reference compound.
What makes PT-141 distinct
PT-141 is a metabolite of Melanotan II with the C-terminal amide replaced by a hydroxyl group, which shifts its receptor selectivity away from the melanocortin-1 receptor (MC1R).
Research-use status
- Pharmacological class: melanocortin MC3R and MC4R receptor agonist
- Published literature is mostly animal and clinical work
- Sold for laboratory research use only; this page does not summarise effects or uses
COA and verification considerations
Because research compounds are unregulated, the certificate of analysis is the single most important thing to check. For PT-141, a trustworthy COA names the testing laboratory, reports HPLC purity (typically 99% or higher), confirms identity by mass spectrometry, and, for injectable-format material, includes endotoxin and sterility results. A batch or lot number that matches the product, a recent test date, and a working verification portal are strong positive signals.
What to check before buying
- Is a named third-party lab shown, not just a claim of testing?
- Does the COA lot number match the batch you are buying, with a recent date?
- Are purity and identity both reported, ideally with endotoxin and sterility?
- How does the vendor rank on our published, testing-led formula?
Frequently Asked Questions
Is PT-141 the same as Melanotan II?
No. PT-141 is a metabolite of Melanotan II with a modified C-terminus. The two share a common origin but differ in receptor selectivity, and vendors list them as separate compounds.
What purity should a PT-141 COA show?
Look for a named third-party lab reporting HPLC purity of 99% or higher, with identity confirmed by mass spectrometry. Injectable-format research material ideally also reports endotoxin and sterility results.
How do we rank PT-141 vendors?
By the same published formula used site-wide: primarily third-party lab testing and COA verification, then shipping, pricing, tenure, and transparency. Affiliate status never affects the ranking.