What Is PT-141?
PT-141 (bremelanotide) is a cyclic 7-amino-acid peptide and melanocortin receptor agonist. It is unique among reclassification peptides in that it has achieved full FDA approval — marketed as Vyleesi by AMAG Pharmaceuticals (now Covis Pharma) for hypoactive sexual desire disorder (HSDD) in premenopausal women. Despite this approval, PT-141 is also widely available through compounding pharmacies and research vendors.
PT-141 is the only peptide in the expected reclassification list that has an FDA-approved commercial product. This gives it a stronger clinical evidence base than most peptides, but also a more complex regulatory picture for compounding.
Quick Facts
| Property | Detail |
|---|
| Amino Acids | 7 (cyclic) |
| Molecular Weight | ~1,025 Da |
| Brand Name | Vyleesi (FDA-approved) |
| Mechanism | Melanocortin 4 receptor (MC4R) agonist |
| Regulatory Status | Expected Category 1 reclassification |
| FDA Approved | Yes — for HSDD in premenopausal women |
| Prescription Required | Yes (brand and pharmacy); No (research vendor) |
Research Areas of Interest
- Sexual dysfunction — the primary studied and approved application (female HSDD; off-label for male ED)
- Erectile dysfunction — studied in males as an alternative mechanism to PDE5 inhibitors (Viagra/Cialis)
- Melanocortin system — acts centrally in the brain rather than peripherally, unlike other ED medications
- Related to Melanotan II — PT-141 was derived from Melanotan II but without the tanning effects
How It's Sold
| Source | Form | Prescription? | Typical Cost |
|---|
| Brand (Vyleesi) | Pre-filled autoinjector | Yes (Rx) | $800-1,000+/dose |
| Compounding Pharmacy | Injectable (subcutaneous) | Yes | $80-250/month |
| Compounding Pharmacy | Nasal spray | Yes | $80-200/month |
| Compounding Pharmacy | Oral troche/lozenge | Yes | $60-180/month |
| Research Vendors | Lyophilized powder (10mg vial) | No | $30-70/vial |
Brand vs. Compounded
| Factor | Vyleesi (Brand) | Compounded PT-141 |
|---|
| FDA Approved | Yes | No (compounded) |
| Cost | ~$800-1,000/dose | $80-250/month |
| Availability | Limited (specialty pharmacy) | Widely available |
| Forms | Autoinjector only | Injectable, nasal, troche |
| Insurance | Rarely covered | Not covered |
What to Look For on the COA
- HPLC purity — minimum 95%, ideally 98%+
- Mass spectrometry — confirmed MW of ~1,025 Da
- Cyclic structure verification — PT-141 is a cyclic peptide; linear forms are not equivalent
- Endotoxin testing — required for injectable forms
- Sterility testing — important for nasal spray forms
Storage Guide
- Lyophilized: Store at 2-8°C; -20°C for long-term
- Reconstituted: Refrigerate at 2-8°C. Use within 21 days
- Nasal spray: Refrigerate after opening. Follow pharmacy instructions for expiration
Key Sourcing Tips
- Always request and verify the COA — batch numbers must match your product label
- PT-141 is a cyclic peptide — ensure your vendor tests for the correct cyclic structure, not a linear analog
- Brand Vyleesi exists but is expensive and limited — most users access PT-141 through compounding pharmacies
- Multiple delivery forms are available — discuss options with your prescribing provider
- For personal use: work with a licensed provider and compounding pharmacy
- Do not confuse PT-141 with Melanotan II — they share a lineage but have different structures and effects