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PT-141

Sexual health

Also known as: Bremelanotide, Vyleesi, PT141

A melanocortin agonist that acts in the brain to raise sexual desire. Approved as Vyleesi for low desire in premenopausal women.

Safety:Approved for one use in women, low sexual desire. Use in men is off label. Nausea is very common, and it can raise blood pressure, so it is not for uncontrolled high blood pressure or heart disease.

2.What it is / mechanism

PT-141, also called bremelanotide, is a melanocortin that works in the brain rather than on blood flow. By acting on MC4 receptors it raises sexual desire and arousal. This is different from drugs like sildenafil (Viagra), which mainly improve blood flow. It is a close relative of Melanotan II but is used for desire rather than tanning. It is approved by the FDA as Vyleesi for hypoactive sexual desire disorder in premenopausal women.s1

3.What the evidence supports

  • Strong human dataRaises sexual desire in premenopausal women with low desire.s1

    Approved by the FDA in 2019 based on the phase 3 RECONNECT trials.

  • Limited human dataHelps libido and erections in men.s2

    Used off label in men, with some supporting studies, but this is not an approved use.

4.Dosing

Strong human data
Route(s)subcutaneous
Typical rangeThe approved dose is 1.75 mg, taken as needed at least 45 minutes before sex, with no more than 8 doses per month. Doses used in men are often lower.
FrequencyAs needed, not daily. No more than 8 times a month.
Cycle guidanceUsed on demand, not in cycles.
NotesBecause it is used on demand rather than daily, it does not build up. The limit of 8 doses a month exists because frequent use can cause patchy skin darkening. Take it well before activity, since nausea peaks early.
s1

5.Reconstitution

Vial sizes10 mg
DiluentBacteriostatic water for multi dose vials, or sterile water for single use
ConcentrationExample: a 10 mg vial plus 1 mL of water gives 10 mg/mL, so a 1.75 mg dose is 0.175 mL, which is about 18 units on a U-100 syringe.
NotesThe approved product (Vyleesi) is a prefilled autoinjector. Research material is usually a 10 mg freeze dried vial.

Reconstitution calculator

Pick your vial size and how much water you add to see the draw volume and syringe units for a dose. Open the full calculator →

Inputs

Reminder: 1 mg = 1,000 mcg

mg

Total amount stated on the vial, e.g. 5 mg.

mL

How much diluent you draw into the vial.

mcg

Target dose per injection, in mcg. 1 mg = 1,000 mcg.

Result

Draw to

5 units

= 0.05 mL on your syringe

Concentration
5,000 mcg/mL
Per unit
50 mcg / unit
Doses per vial
40

Educational estimate only. Not medical or dosing advice. Verify every calculation independently before use.

General reconstitution technique →

6.Storage & stability

Lyophilized (dry)

TempFreeze for long term storage, or 2 to 8 short term
Shelf lifeMany months when frozen
NotesKeep dry and out of light until you mix it.

Reconstituted

Temp2 to 8 (refrigerated)
Shelf lifeAbout 2 to 4 weeks
NotesDo not freeze after mixing. Discard if cloudy or discolored.

General storage & stability guide →

7.Reported side effects

  • WarningTemporary rise in blood pressure and drop in heart rates1Usually mild and short, but it is why heart conditions matter.
  • WarningPatchy skin darkening with frequent use(uncommon)s1More likely if you go over the monthly dose limit.
  • CautionNausea(common)s1Very common, about 40 percent on the first dose, and it fades with use. Taking it earlier before activity helps.
  • CautionFacial flushing(common)s1
  • CautionHeadache(common)s1

8.Interactions & stacking risks

  • CautionBlood pressure mediciness1

    It transiently raises blood pressure, so discuss timing with your prescriber.

  • WarningOral naltrexones1

    PT-141 can lower naltrexone levels, which matters for anyone using it for alcohol or opioid dependence.

  • CautionMelanotan II or other melanocortin agonists

    They share a mechanism, so combining adds to the nausea and blood pressure effects.

9.Contraindications / who should avoid

  • SeriousUncontrolled high blood pressure or known heart disease

    It can raise blood pressure, so it is not for uncontrolled hypertension or cardiovascular disease.

  • SeriousPregnancy or breastfeeding

    No safety data in pregnancy or breastfeeding.

10.COA & purity notes

Common adulterantsunderdosed or mislabeled research vials, research material sold without the controls of the approved product
MislabelingThere is an approved product (Vyleesi) made to pharmaceutical standards. Research vials are not, so a recent third party COA matters.
NotesPT-141 has an FDA approved version (Vyleesi) for women. Research or off label material is not the same product.

How to read a COA →

11.Sources

  1. [s1]U.S. FDA / Obstetrics & Gynecology (2019). Bremelanotide (Vyleesi) approval and the RECONNECT phase 3 trials. rct link
  2. [s2]Clinical review (2024). PT-141 (bremelanotide) for sexual dysfunction: clinical overview. review

Last reviewed 2026-07-08 · status: reviewed