PT-141 Liquid Spray

Graded C: small early human studies of nasal bremelanotide exist, but the nasal program was stopped and never approved; the approved Vyleesi product is a different formulation.

Strengths: 10 mg in 10 mL (1 mg/mL)
Also known as: Bremelanotide, Vyleesi (approved brand)
Contains: Bremelanotide (PT-141)
Molecule: Cyclic 7-amino-acid melanocortin peptide
Formula: C50H68N14O10
Mol. weight: 1025.16 g/mol
CAS: 189691-06-3
Sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH

Origin

Bremelanotide was developed from MT-2. Its developer tested nasal sprays in the 2000s; FDA halted those trials in 2007 over blood-pressure rises, and the company switched to the formulation later approved as Vyleesi.

How it works

Bremelanotide activates melanocortin receptors in the brain involved in sexual arousal pathways. A 2004 nasal study found it reached peak blood levels in about 30 minutes with a half-life of about 2 hours.

What the research shows

A 2004 double-blind, placebo-controlled study in men found effects greater than placebo only in the higher-exposure study arms. Phase 2 nasal trials in women and men followed, but FDA put them on hold in 2007 over blood-pressure increases, and nasal development ended in 2008. No published figure exists for how much nasal bremelanotide is absorbed.

Key studies

Diamond et al., Int J Impot Res 2004 Placebo-controlled nasal study in men; flushing and nausea most common; half-life about 2 hours.
Vyleesi prescribing information, FDA 2019 The approved product causes a transient rise in systolic blood pressure.

Safety findings

Blood-pressure rises are why regulators stopped the nasal program, and the approved product's label contraindicates uncontrolled hypertension and known cardiovascular disease. Label warnings also include nausea, flushing, and skin or gum darkening, more common with more frequent administration, and it slows stomach emptying, affecting oral drugs such as naltrexone.

Regulatory status

The molecule is FDA-approved only as Vyleesi, a prescription product for a specific condition in premenopausal women; no nasal product was ever approved. Not on FDA's safety-risk list or 503A categories document; as a component of an approved drug it can in principle be compounded with a prescription. Not named on the 2026 WADA List; as an approved drug, S0 does not apply.

Catalog notes

Offered as 10 mg in 10 mL; the 10 mg powder vial has a certificate (COA7625, 99.85%). No spray-specific certificate is published yet, and the vehicle, preservative, pH, sterility and salt form are not listed.