PT-141 is bremelanotide, a melanocortin drug that acts on brain pathways involved in sexual desire.
What PT-141 does and why that matters
PT-141 is bremelanotide, the active ingredient in Vyleesi. It activates melanocortin receptors in nervous-system pathways linked to sexual desire rather than directly increasing genital blood flow. The practical goal is to increase desire and reduce the distress caused by persistently low desire. FDA approval is limited to certain premenopausal women with acquired, generalized HSDD; the precise reason it helps some patients is still unknown. [1,2]
Function evidence: Approved for a specific condition; exact brain action unclear
What the approved benefit means
For an eligible patient with acquired, generalized HSDD, the goal is not a guaranteed physical response or a performance boost. It is a meaningful increase in sexual desire and less distress about persistently low desire. The phase 3 trials found average improvements on validated desire and distress questionnaires compared with placebo, but individual responses varied. The approval does not extend to increasing libido in everyone, treating relationship problems, or using unapproved formulations with different instructions. [1,2,3]
What supports this description: Randomized phase 3 outcomes supporting a narrow FDA-approved indication
PT-141 Dosing status
Dose: Vyleesi: 1.75 mg | Frequency: As needed, at least 45 minutes before anticipated sexual activity | Cycle: Stop after 8 weeks if symptoms have not improved | Route: Subcutaneous, abdomen or thigh
Preparation: None: 1.75 mg/0.3 mL single-dose prefilled autoinjector.
No more than one dose in 24 hours; more than eight doses per month is not recommended. These are Vyleesi label instructions. Compounded vials and nasal sprays do not have this product's FDA approval. [1,3]
PT-141 Effects
Desire and related distress. The RECONNECT trials found statistically significant improvements in questionnaire scores for sexual desire and distress compared with placebo. Individual responses vary. [2]
PT-141 Side Effects
Blood pressure and heart rate. Blood pressure can rise and heart rate can fall after a dose. Vyleesi is contraindicated with uncontrolled hypertension or known cardiovascular disease. [1, sections 4–5]
Nausea and other common reactions. Nausea, flushing and headache were common in the phase 3 trials. Nausea sometimes led participants to stop treatment. [2]
Skin darkening. Focal hyperpigmentation can occur, and resolution after stopping was not confirmed in every patient. [1, section 5.2]
Interactions and pregnancy. Delayed gastric emptying can affect oral medicines. Avoid oral naltrexone products used for alcohol or opioid addiction. Use effective contraception and stop if pregnancy is suspected. [1, sections 7–8]
Frequently Asked Questions About PT-141
Who is Vyleesi approved for?
Premenopausal women meeting the acquired, generalized HSDD criteria. It is not indicated for men, postmenopausal women or sexual performance enhancement. [1]
How long does a dose work?
The label specifies administration at least 45 minutes before anticipated activity. The duration of benefit and optimal timing window have not been fully established. [1]
Does a PT-141 vial have the same approval?
FDA approval applies to Vyleesi's formulation and labeled use. Compounded drugs are not FDA-approved, and their preparation instructions must come from the dispensing pharmacy. [1,3]
Evidence
Approved for a defined HSDD population. Two randomized phase 3 trials found improvements in desire and distress scores in premenopausal women with acquired, generalized HSDD. These results apply to the studied population and formulation. [1,2]
Approval status: FDA-approved as Vyleesi for a specific HSDD indication
References
Cosette Pharmaceuticals Vyleesi (bremelanotide) prescribing information Prescribing information, 2024. Source
Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol, 2019. PMID 31599840
U.S. Food and Drug Administration Human Drug Compounding FDA, 2026. Source
Storage
Vyleesi autoinjector: Store at or below 25°C (77°F), protected from light. Do not freeze. [1, section 16]
Educational evidence summary. Approval applies only to the named product and indication; compounded, investigational, and research-market products are different categories.
◇An FDA-approved label or a patient-specific prescription from a licensed pharmacy
◇The active ingredient, strength, dosage form, concentration, lot, and dispensing instructions
◇Identity or purity tests only support the tests performed; they do not prove sterility, endotoxin safety, dose accuracy, stability, or clinical suitability
◇A “research use only” vial is not a patient medicine
