You can buy PT-141 from a pharmacy on a prescription, or from a research-supply vendor without one, and that's the entire answer to where to buy PT-141. The pharmacy version is called Vyleesi and costs about $300 a dose. The research vial costs $40–$80 and holds the same molecule under a different label.
PT-141
Referenced in this guideThe PT-141 referenced throughout this article, supplied as a research compound with a certificate of analysis matched to the lot you receive — the check this site argues you should hold any supplier to.
PT-141, or bremelanotide, is a synthetic 7-amino-acid cyclic peptide, approved by the FDA as Vyleesi in 2019 for premenopausal HSDD, a diagnosed loss of desire. A pharmacy can fill it, and the research vial holds the same molecule at $40–$80 per 10 mg. Two traps follow you either way: melanotan II sold as PT-141, and male-ED claims.
The 60-second answer. For an approved human use, the prescription is the route and Vyleesi is what your pharmacy dispenses. For the reference compound, a research vendor ships powder with a third-party CoA: HPLC ≥98%, mass-spec at [M+H]+ 1026.2. That mass line separates real PT-141 from melanotan II.
Where can you buy PT-141?
You can buy PT-141 in two places: a retail pharmacy, on a prescription for Vyleesi, or a research-supply vendor selling the same molecule as powder. PT-141 has the cleanest split of any compound in this library, because the FDA approved it.
- A retail pharmacy, on prescription. Vyleesi costs about $300 per dose at cash pay. You get a pre-filled single-dose autoinjector holding 1.75 mg of bremelanotide, made under cGMP and dispensed by a licensed pharmacy. The approval covers premenopausal HSDD only. Some telehealth services will prescribe it when you meet the clinical criteria. This is the legitimate path for human use.
- A research-supply vendor, no prescription. $40–$80 per 10 mg vial of lyophilized powder, sold under Research Use Only labeling. It's the same chemical entity as Vyleesi's active ingredient. Different regulatory framing, different manufacturing pathway, and a different intended use.
There's no third route. A compounding pharmacy can't make PT-141 for you, because Vyleesi is commercially available and isn't on the FDA Drug Shortage list. That closes the 503A exemption that opens up for tirzepatide.
What the research route leaves out. No prescription, no physician, no insurance, no FDA-regulated batch testing, no sterile autoinjector, and no authorization for the use Vyleesi is approved for. We'd read the $260 gap as the price of all that. It isn't a difference in the molecule.
Which vendors should be on your PT-141 shortlist?
A channel is not a shortlist, so here is one. Of the 16 storefronts we checked on 13 August 2026, these six published the most: a third-party certificate you can open, and a testing lab you can name. The table scores the vendor rather than the catalog, so confirm PT-141 itself is in stock before you order. Pricing across this same set is benchmarked on BPC-157, the one compound all six carry — no PT-141 price was verified across these vendors, so there is no price column here rather than an estimated one.
| Vendor | COA | Lab named | Ships free at |
|---|---|---|---|
| Peptriva Premium brand | Third-party, published | Freedom Diagnostics — on the product page | $200 |
| Sports Technology Labs | Third-party, published | MZ Biolabs and Colmaric — on the site and the document | $149 |
| Swiss Chems | Third-party, published | Janoshik — on the site | $100 |
| Core Peptides | Third-party, published (A2LA #6377.01.01) | Vanguard Laboratory — document only | $200 |
| PS Peptides | Third-party, published | North American Diagnostics — document only | $200 |
| BioTech Peptides | Third-party, published | MZ Biolabs — document only | $200 |
Three vendors from the same survey are absent on purpose. Red Rock Peptides advertises “Verified With COAs” and publishes no certificate at all. Limitless Biotech gates every price behind an account, so nothing it offers can be compared against anything. Behemoth Labz does publish, but its newest genuine certificate is dated August 2024. The full ranking, with the price column, is in our comparison of peptide companies. Disclosure: this site earns a commission on purchases made through its links, Peptriva included — which is why every column above is a document you can open or a figure you can load for yourself.
On the certificate, PT-141 should carry CAS 189691-06-3 on the identity line, alongside the mass-spec reading set out below — melanotan II sits about a dalton away, so a certificate showing purity and no mass cannot separate the two.
What is PT-141?
PT-141 is a 7-residue cyclic peptide. The sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH. It started life as a breakdown product of melanotan II.
Palatin Technologies developed it deliberately as a sexual-desire therapy, after researchers noticed sexual side effects in people given melanotan II. The two molecules share a cyclic core and differ at the tail. Bremelanotide drops the C-terminal extension that melanotan II carries, as Pfaus and colleagues describe.
The FDA approved it as Vyleesi in June 2019, for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Two 24-week placebo-controlled Phase III trials carried the approval. RECONNECT-1 and RECONNECT-2 enrolled 1,247 and 1,202 women, Simon and colleagues reported.
“
Bremelanotide acts centrally on MC4R-expressing neurons to modulate dopaminergic signaling and sexual desire, mechanistically distinct from peripheral PDE5 inhibitors.
— Pfaus et al., 2022, a neurobiology review.
How do you verify PT-141 before you buy?
Four checks decide whether a PT-141 vial is genuine. Which channel it came from. The mass-spec reading at 1025.2 Da. The melanotan II substitution risk. And whether the vendor understands the mechanism it's selling. The standard eight vendor criteria apply on top.
1. Channel match: Vyleesi vs third-party tested
Bremelanotide is one of only two FDA-approved peptides in this library. Tesamorelin is the other. That changes what a vendor is allowed to say.
A credible research vendor sells PT-141 as a Research Use Only reference compound. No clinical claims, no therapeutic dosing instructions, no pitch as a cheap Vyleesi. The molecule is the same. The labeling and the intended use are not.
A vendor that blurs those two has crossed into FDA jurisdiction. Read that as a signal about everything else it tells you.
2. Mass-spec at 1025.2 Da
The theoretical mass is 1025.2 g/mol, so the CoA mass-spec should land at [M+H]+ 1026.2, within half a dalton. CAS 189691-06-3 belongs on the identity line.
This is the single most important check you can make. Melanotan II, the close cousin, sits at 1024.2 Da. That's 1 Da apart, which any credible instrument resolves easily. A CoA with no mass line at all is a deal breaker.
3. Melanotan II substitution risk
PT-141 and melanotan II are structurally adjacent. Both are 7-residue cyclic peptides. Both are non-selective melanocortin agonists. Both came from the same University of Arizona / Palatin Technologies program.
Mestria and colleagues ran high-resolution mass spectrometry across grey-market products and found both peptides in adulterated material. Sometimes the label didn't match what was measured. So we treat mass-spec confirmation as non-optional here, and you should too.
4. PT-141 is mechanistically distinct from sildenafil
Grey-market copy often implies PT-141 works the way Viagra does. Published mechanistic reviews describe something else entirely.
Sildenafil and tadalafil act peripherally, on smooth muscle in penile vasculature. PT-141 acts centrally, on MC4R neurons in the hypothalamus, where it modulates dopamine signaling. Sweeney and colleagues set out the pathway.
Different stage of the response, different target. That's why the female-HSDD data doesn't transfer cleanly to male ED. The Phase III program for male indications was discontinued.
What does PT-141 cost in 2026?
PT-141 costs $40–$80 per 10 mg vial as a research compound, against about $300 a dose for prescription Vyleesi. It takes one cyclization step and one D-amino acid, D-Phe, to make. That's moderate synthesis complexity: harder than BPC-157, easier than tirzepatide. Here's what you'll pay in 2026.
- 10 mg vial: $40–$80 ($4–$8/mg). Most common size.
- 5 mg vial: $30–$55 ($6–$11/mg). Worse per-mg value.
- Multi-vial discounts: 10–25% off for 3-pack or 6-pack purchases.
For comparison, prescription Vyleesi costs about $300 per single-dose autoinjector. That gap buys cGMP manufacturing, sterile autoinjector engineering, a prescriber consultation, insurance billing and pharmacy prep. It does not buy a different molecule.
Below $30 per 10 mg vial, something got skipped. The cyclization and the D-amino acid are real costs nobody can synthesize their way around. Sub-floor pricing is a documented marker of skipped purification, or of a cheaper analog in the vial. Melanotan II is the one to worry about.
Is PT-141 legal to buy?
PT-141 is legal to buy in the US as a research reference compound, and legal to obtain as medicine on a prescription. Bremelanotide is FDA-approved as Vyleesi for premenopausal HSDD, which changes the regulatory picture in three ways.
- Vyleesi requires a prescription. The pharmacy route is legitimate for human use in the approved indication. Telehealth services will prescribe it when you meet the clinical criteria.
- Research-compound sales are legal. PT-141 ships in the US as a Research Use Only reference compound, the same way other approved drug molecules are sold as analytical reference standards.
- Off-label male use is outside the approval. The male-indication Phase III program was discontinued. Selling PT-141 as research material without therapeutic claims is legal. Selling it as a male-ED treatment is not.
What are the red flags when buying PT-141?
Seven things would make us walk away from a PT-141 listing. Most of them come down to a vendor blurring the line between a research compound and an approved drug.
- Mass-spec at the wrong mass. Anything materially off 1026.2 [M+H]+ means the vial isn't PT-141. Melanotan II substitution is documented in grey-market analytical work.
- Clinical claims for male ED. “Treats male ED.” “Better than Viagra.” The male-indication Phase III program was discontinued. FDA jurisdiction.
- Therapeutic administration instructions on the product page. Prescribing-schedule language mirroring the Vyleesi label indicates a vendor positioning the compound for human use rather than laboratory research.
- Marketed as a Vyleesi substitute. Same molecule, different channel. A vendor pitching cheap Vyleesi is selling an unapproved version of an FDA drug.
- Missing CAS 189691-06-3 on the CoA. The unique identifier. Its absence is a red flag.
- Pre-mixed nasal sprays or transdermal patches. The Vyleesi format is a subcutaneous autoinjector. Pre-formulated alternatives aren’t validated in any published controlled study.
- Internal QC only, no third-party ISO 17025 lab. The standard is an outside accredited lab on the report.
“
LC-HRMS characterization of melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs.
— Mestria et al., Drug Testing and Analysis, 2021. The paper behind the mass-spec rule above.
PT-141 (Bremelanotide)
Cyclic heptapeptide, CAS 189691-06-3, theoretical MW 1025.2 g/mol. The same reference compound used across the RECONNECT Phase III dataset and the Clayton pooled safety analysis. COA with HPLC trace and mass-spec ships with every order — the mass-line confirmation that separates verified PT-141 from melanotan II substitution.
Frequently asked questions
Is PT-141 the same as Vyleesi?
Chemically, yes. Same cyclic 7-residue peptide, same CAS number, same mass. What differs is the regulatory framing, the supply chain, the manufacturing quality and the dosage form. Vyleesi is the finished product, made under cGMP and dispensed by a pharmacy on your prescription. The research version is lyophilized powder under Research Use Only labeling.
How much does PT-141 cost vs Vyleesi?
You'll pay about $300 per single-dose Vyleesi autoinjector at cash pay, against $40–$80 per 10 mg research vial. The research price doesn't include the prescription, the autoinjector engineering, the pharmacy prep or the cGMP overhead.
Is PT-141 legal without a prescription?
Yes, as a research reference compound, the same as other approved drug molecules sold as analytical reference standards. Selling PT-141 as a therapeutic without a prescription is illegal. Buying it from a supplier that labels and ships it Research Use Only isn't.
PT-141 vs melanotan II, which one is which?
PT-141 is the approved one, sold as Vyleesi since 2019. Melanotan II has never been approved anywhere, and grey-market use has produced documented serious adverse events. Both are cyclic 7-residue peptides and non-selective melanocortin agonists. PT-141 weighs 1025.2 Da, melanotan II 1024.2 Da. A credible instrument resolves that 1-Da difference without difficulty.
What does PT-141 do mechanistically?
Published studies have investigated PT-141 as a non-selective melanocortin receptor agonist with primary activity at MC4R in the hypothalamus. MC4R activation has been reported to increase dopaminergic signaling in preclinical and clinical models. Mechanistic reviews note this is distinct from PDE5 inhibition, which acts peripherally on vascular smooth muscle rather than centrally on CNS signaling. See PT-141 MC4R CNS mechanism.
What should a PT-141 CoA show?
CAS 189691-06-3. HPLC purity ≥98% with the chromatogram attached. Mass-spec at [M+H]+ 1026.2. Water content 2–8% by Karl Fischer titration. Counterion content, usually trifluoroacetate at 5–15% by mass. An ISO 17025-accredited lab named on the report.
The mass-spec line is the one we'd refuse to buy without. It's your only defense against melanotan II substitution.
What to know now
- Two routes, and one of them is a pharmacy. A prescription for Vyleesi, or a research vial without one. There is no compounding route, because Vyleesi isn't in shortage.
- CAS 189691-06-3, MW 1025.2, [M+H]+ 1026.2. The identity parameters a research CoA should confirm.
- $40–$80 per 10 mg vial. Moderate synthesis complexity: a cyclic 7-mer with one D-amino acid.
- FDA-approved as Vyleesi in 2019. Same molecule, different channel. The prescription runs $300 per dose.
- Mass-spec is non-optional. Melanotan II substitution is documented in grey-market analytical work.
- CNS-active, not a peripheral vasodilator. Mechanistic reviews describe MC4R-mediated central dopamine signaling, which is not how PDE5 inhibitors work.
- Male Phase III program was discontinued. The FDA approval covers premenopausal HSDD only.
What we’re watching
Two things would change what we tell you about PT-141. The first is a new Phase III program for the male sexual-function indication. The original was discontinued. A fresh trial would either close the off-label evidence gap or confirm the female-HSDD data doesn't transfer.
The second is more surveillance of the grey market. Mestria's 2021 analysis is still the canonical reference for substitution. Until something newer publishes, mass-spec identity confirmation stays the check we won't waive.
References
- Pfaus, J. G., Sadiq, A., Spana, C., & Clayton, A. H. (2022). The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectrums, 27(3), 281–289. https://doi.org/10.1017/S109285292100002X
- Simon, J. A., Kingsberg, S. A., Portman, D., et al. (2022). Prespecified and integrated subgroup analyses from the RECONNECT Phase 3 studies of bremelanotide. Journal of Women’s Health, 31(3), 391–400. https://doi.org/10.1089/jwh.2021.0225
- Clayton, A. H., Kingsberg, S. A., Portman, D., et al. (2022). Safety profile of bremelanotide across the clinical development program. Journal of Women’s Health, 31(2), 171–182. https://doi.org/10.1089/jwh.2021.0191
- Sweeney, P., Gimenez, L. E., Hernandez, C. C., & Cone, R. D. (2023). Targeting the central melanocortin system for the treatment of metabolic disorders. Nature Reviews Endocrinology, 19(9), 507–519. https://doi.org/10.1038/s41574-023-00855-y
- Mestria, S., Odoardi, S., Frison, G., & Strano Rossi, S. (2021). LC-HRMS characterization of melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs. Drug Testing and Analysis, 13(4), 876–882. https://doi.org/10.1002/dta.2986
- U.S. Food and Drug Administration. (2019). Vyleesi (bremelanotide injection) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
- International Organization for Standardization. (2017). ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories. https://www.iso.org/standard/66912.html