What Is PT-141 Peptide?
PT-141 is the research code for bremelanotide, a synthetic cyclic heptapeptide: seven amino acids, several of them joined into a ring that makes the molecule resistant to breakdown. It was developed by Palatin Technologies from Melanotan II, the tanning peptide created at the University of Arizona, after researchers noticed that Melanotan II had effects on sexual arousal as well as on skin pigmentation.
Chemically the two are close relatives. PT-141 is essentially Melanotan II with one change at the end of the chain, where an amide group is replaced by a free acid. That small change shifts the balance of which melanocortin receptors it acts on, and it is why PT-141 was developed for a different purpose.
How Does PT-141 Work?
PT-141 is a melanocortin receptor agonist, acting mainly on the MC4 and MC3 receptors in the brain, particularly in the hypothalamus. That makes it different in kind from PDE5 inhibitors such as sildenafil, which act on blood flow: PT-141 works on the central nervous system pathways involved in arousal rather than on the vascular system. That central mechanism is why it attracts research interest.
Browse the published work, with links to each paper, in our PT-141 research library.
PT-141 as a Drug: Bremelanotide
People searching for the PT-141 drug are usually looking for bremelanotide's clinical history. In 2019 the US Food and Drug Administration approved bremelanotide under the brand name Vyleesi, as a subcutaneous autoinjector for a specific indication in premenopausal women. That approval sits behind years of clinical trials, and it makes PT-141 one of the few research peptides with a completed regulatory pathway in another country.
The PT-141 supplied by Chainwell Peptide is a research compound, not that registered medicine, and it is not approved by the Therapeutic Goods Administration for any therapeutic use.
Does PT-141 Cause Tanning? PT-141 and Melanotan II
Because PT-141 comes from Melanotan II, it is often asked whether it also darkens the skin. Its receptor profile favours MC4 and MC3 over MC1, the receptor that drives pigmentation, so it is much less of a tanning compound than Melanotan II. Even so, skin darkening in a small proportion of participants was among the effects reported in bremelanotide's clinical trials. For research on pigmentation itself, Melanotan II and Melanotan 1 are the relevant compounds, and all three sit in our melanocortin research peptides range.
PT-141 10mg Vial
The PT-141 10mg vial holds the peptide as a white freeze-dried cake in a 3 mL clear glass vial with a rubber stopper and orange flip-off cap. Supplying it dry keeps it stable in storage and transit, and lets you set the concentration yourself.
To reconstitute PT-141, add bacteriostatic water slowly down the inside wall with a U-100 insulin syringe and swirl gently until clear; do not shake. As a worked example, 2 mL in the 10mg vial gives 5mg per mL. How long does PT-141 last after reconstitution? Keep it in the fridge at 2 to 8 °C, protected from light, and use it within 28 days; unopened, the lyophilized vial keeps longest frozen at minus 20 °C. Our reconstitution guide and calculator covers other volumes.
PT-141 Nasal Spray
PT-141 nasal spray has a real research history behind it: bremelanotide was first developed and trialled as an intranasal formulation, and its developer later moved to a subcutaneous injection after blood pressure increases were reported with the nasal version. That history is why searches for PT-141 nasal spray, and comparisons of PT-141 nasal spray vs injection, are so common. Chainwell Peptide supplies PT-141 in that format as a 10 mL nasal spray bottle holding 10mg in solution, 1mg per mL, under a white pump actuator.
The spray needs no preparation: there is no powder to reconstitute and no diluent to measure, and the concentration is fixed at 1mg per mL. Keep the bottle refrigerated at 2 to 8 °C, protected from light, and follow the expiry on the label. Every spray lot is tested by an independent laboratory for identity and purity. Like the vial, the PT-141 nasal spray is supplied for research use only.
PT-141 Vial or Nasal Spray?
| 10mg vial | Nasal spray | |
|---|---|---|
| Form | Lyophilized (freeze-dried) powder | Solution, 1mg per mL |
| Container | 3 mL glass vial, orange flip-off cap | 10 mL bottle, pump actuator |
| Preparation | Reconstitute before use | None |
| Concentration | Set by you | Fixed at 1mg per mL |
| Storage | Frozen long term; 2 to 8 °C once reconstituted | 2 to 8 °C, protect from light |
Our recommendation: choose the vial when your work needs PT-141 at a concentration or in a vehicle you choose, or when you want the longest shelf life. Choose the PT-141 nasal spray when your research design specifically calls for the intranasal format.
Lab-Tested PT-141 With a COA for Every Lot
PT-141 and Melanotan II differ by a single group at the end of the chain, so a mass check is the only reliable way to tell them apart. Every Chainwell Peptide PT-141 lot, vial and spray alike, is sent to an independent laboratory before release: mass spectrometry confirms the molecular mass matches bremelanotide, about 1,025 g/mol, and HPLC measures purity. A lot that does not meet specification is not sold. Check your lot on our COA lookup page.
Buy PT-141 in Australia
Chainwell Peptide supplies PT-141 peptide in Australia to laboratories, universities and independent researchers, packed and dispatched from within Australia. Before you buy PT-141 from any supplier, check that the listing states the fill and format, that the vial or bottle carries a lot number, and that the certificate for that lot is available before you pay.
- Same-day dispatch on orders paid before 3pm on a business day.
- Australia-wide delivery to Sydney, Melbourne, Brisbane, Adelaide, Perth, Hobart, Darwin and regional addresses, by standard or express post.
- PayID or bank transfer, with your order number as the payment reference.
- Tracked orders you can follow on our order tracking page.
The current price for each format is shown at the top of this page, with GST included. See our shipping policy for delivery details.
PT-141 Specifications
| Compound | PT-141 (bremelanotide) |
|---|---|
| Class | Cyclic heptapeptide, melanocortin receptor agonist (MC4R, MC3R) |
| Parent compound | Melanotan II |
| Molecular formula | C50H68N14O10 |
| Molecular weight | Approximately 1,025.2 g/mol |
| Formats | 10mg lyophilized vial; 10 mL nasal spray, 10mg at 1mg per mL |
| Containers | 3 mL glass vial with orange flip-off cap; 10 mL bottle with pump actuator |
| Identity and purity | Mass spectrometry and HPLC, per lot |
| Diluent | Vial: bacteriostatic water, sold separately. Spray: none needed |
| Storage | Vial: minus 20 °C long term. Spray and reconstituted vial: 2 to 8 °C, protect from light |
| Shipping | Standard or express post, Australia-wide |
Research Use Only
PT-141 supplied by Chainwell Peptide is a research compound, not a registered medicine, and it is not approved by the Therapeutic Goods Administration for any therapeutic use. We sell it strictly for laboratory and in vitro research, in both vial and spray formats. It is not for human or veterinary use, and we do not provide dosing advice. By ordering you agree to our terms and conditions and research use only statement.
PT-141 tools and guides
- PT-141 Dosage Calculator: bac water, concentration and U-100 syringe units
- Melanotan 1 vs 2: Afamelanotide, Melanotan II and PT-141 Compared
PT-141 FAQ
What is PT-141?
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PT-141 is bremelanotide, a synthetic cyclic seven amino acid peptide developed from Melanotan II. It activates melanocortin receptors in the brain and is studied in research on central arousal pathways. Chainwell Peptide supplies it as a 10mg lyophilized vial or a 10 mL nasal spray.
How does PT-141 work?
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PT-141 acts mainly on the MC4 and MC3 melanocortin receptors in the brain, especially the hypothalamus. Unlike PDE5 inhibitors, which act on blood flow, it works through the central nervous system, which is the focus of research on it.
Is PT-141 the same as bremelanotide?
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Yes. PT-141 is the research code for bremelanotide, approved in the US in 2019 as the injectable medicine Vyleesi. The PT-141 sold by Chainwell Peptide is a research compound, not that registered medicine, and is not approved by the TGA.
Do you sell PT-141 nasal spray?
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Yes. Chainwell Peptide supplies PT-141 as a 10 mL nasal spray holding 10mg in solution at 1mg per mL, as well as a 10mg lyophilized vial. The spray needs no reconstitution; the vial lets you set your own concentration. Both come with a lot-matched certificate of analysis.
Does PT-141 cause tanning?
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Much less than Melanotan II, because PT-141 favours the MC4 and MC3 receptors over MC1, which drives pigmentation. Skin darkening in a small proportion of participants was still reported in bremelanotide clinical trials. For pigmentation research, Melanotan II and Melanotan 1 are the relevant compounds.
Where can I buy PT-141 in Australia?
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You can buy PT-141 in Australia from Chainwell Peptide as a 10mg lyophilized vial or a 10 mL nasal spray. Every lot carries a lot number matched to an independent certificate of analysis, and orders paid before 3pm on a business day ship the same day by standard or express post.
