Melanocortin Peptides UK: PT-141 (Bremelanotide)

Agonists at the melanocortin receptors. PT-141 (bremelanotide) is licensed in the USA for one indication and unlicensed in the UK; it is listed here only with legal advice and supplied for laboratory research. Lot-tested with certificates published per batch.

In brief: Melanocortin peptides are agonists at the melanocortin receptors; PT-141 (bremelanotide) is the one with controlled human trial data. ALTA PEPTIDES stocks PT-141 (10 mg) in UK stock, with the certificate of analysis published for PT-141 (supplier’s report), dispatched the same working day before 1pm. ALTA PEPTIDES does not stock Melanotan II. Listed with written legal advice and supplied strictly for laboratory research.

The libido and tanning range compared

Compound	Mechanism	Size	Price	Per mg	Certificate
PT-141Bremelanotide	Melanocortin receptor agonist	10 mg vial	£22.99	£2.30/mg	Third-party report (supplier’s, no lot number)

PT-141 and Melanotan II

Most searches for melanotan UK-wide are for Melanotan II, the synthetic melanocortin agonist studied for pigmentation. ALTA PEPTIDES does not stock Melanotan II or Melanotan I, and nothing on this page is a substitute for them. PT-141 is a cyclic heptapeptide derived from Melanotan II with a different receptor profile: it acts centrally at the MC3 and MC4 receptors rather than at the MC1 receptor that drives pigmentation, and it has its own clinical literature and a US licence. The two are related by chemistry, not by research use.

What the research covers

PT-141 has been through controlled human trials in its licensed indication, which report central rather than vascular action and adverse effects including nausea, flushing and transient blood-pressure increases. It is licensed in the United States (as Vyleesi) and not licensed in the UK or EU. Preclinical work examines melanocortin MC3 and MC4 receptor pharmacology more broadly. Among the peptides described online as libido peptides it is the only one with controlled human data, which is why it is the one we list.

Where PT-141 sits

PT-141 is the only compound in this category. The nearest relative elsewhere in the range is KPV in recovery and repair: the C-terminal tripeptide of alpha-MSH, the same parent hormone the melanocortin agonists mimic, but studied for anti-inflammatory signalling that persists in cells lacking melanocortin receptors. The two answer different questions and are not interchangeable. PT-141 counts towards the stack discount when ordered with another single-compound peptide.

Buying in the UK

PT-141 is not a controlled substance in the UK. It is a licensed prescription medicine in the USA and unlicensed here, so it is listed only with written legal advice and supplied strictly as a laboratory reagent, not for human use. Melanotan II is not stocked.

Everything on this page is held in UK stock and dispatched the same working day before 1pm Monday to Friday by Royal Mail Tracked 48 (£4.95, free over £75) in plain packaging. Certificates: published for PT-141 (supplier’s report). That is the manufacturer's or supplier's paperwork published as received; ALTA's own independent test of each lot is added to the certificates page as it arrives. PT-141 counts towards the automatic stack discount when ordered with another single-compound peptide: 10% off the peptide lines for two compounds, 15% for three, 20% for four or more, via the stack builder.

Questions

No. ALTA PEPTIDES does not stock Melanotan II or Melanotan I. PT-141 is a different compound derived from Melanotan II, acting at different receptors, and is the only melanocortin peptide we list.

A search term for melanocortin agonists, principally bremelanotide (PT-141), which acts centrally at the MC3 and MC4 receptors. We describe the published research; the vial is supplied for laboratory use only and not for any use in a person.

PT-141 is not a controlled substance in the UK. It is a licensed prescription medicine in the USA and unlicensed here, which is why it is listed only with written legal advice and supplied strictly as a laboratory reagent.

PT-141: a third-party report from Finnrick Analytics / Krause Analytical, Austin, Texas, obtained by our supplier on its own vial, is published on the certificates page (purity 99.94% by HPLC). Supplier-provided report; no lot number is printed on it, so it cannot be matched to a vial label. Treat as a reference result only until ALTA's own lot test is added. ALTA's own independent third-party test of each lot is pending and is published on the same page as it arrives; no lot is described as independently tested until it is.

Guides for this category

What is PT-141? Bremelanotide, the brain-acting peptide behind Vyleesi, and what the trials showPT-141, or bremelanotide, is a seven-amino-acid ring-shaped peptide that acts on melanocortin receptors in the brain rather than on blood flow. It was approved in the US in 2019 as Vyleesi for low sexual desire in premenopausal women, after two trials found small but real improvements; nausea was common. It is not licensed in the UK. What it is, what the trials found and where it stands.

Other research areas

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Brain & Focus: Nootropic peptides from the Russian literature, supplied as lyophilised powder.
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Water & Accessories: Bacteriostatic water, syringes and swabs for reconstitution.