Skip to content
Easy Peptide Info
Menu
Approved medicine

What is PT-141 (bremelanotide)?

PT-141 explained in plain English: what it is, what the research shows, side effects, legal status and dosage, plus a calculator for syringe units. Doses shown come only from the label or published trials, each with its source. Also called Bremelanotide, Vyleesi.

Bremelanotide is FDA-approved as Vyleesi for one use in premenopausal women. PT-141 sold online as a research peptide is not an approved product. This page is educational; talk with a qualified healthcare professional.

Calculate
Vial unit

= 10,000 mcg

mL
Dose unit
Syringe type
Syringe size

Units to draw

–units

Enter your dose.

Syringe, no result yetU-100, 1 mL syringe holding up to 100 units. Enter your dose.0102030405060708090100

Saved calculations

No saved calculations yet. Save one from the results.

What is PT-141?

PT-141 is the research name for bremelanotide, a lab-made peptide that acts on melanocortin receptors in the brain. It was developed from Melanotan II after researchers noticed that peptide increased sexual arousal.

In 2019 the FDA approved bremelanotide as Vyleesi, an injection pen. PT-141 is also sold online as a powder labeled for research.

What is PT-141 used for?

Vyleesi is approved for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD): low sexual desire that causes distress and isn’t explained by another condition or medicine. It is used as needed before sexual activity, not every day.

Off-label, PT-141 is used by men and women for libido and erectile problems, which hasn’t been approved.

How does PT-141 work?

PT-141 switches on melanocortin receptors (mainly MC4R) in the brain areas that control sexual desire and arousal. Unlike Viagra-type drugs, it doesn’t work mainly by increasing blood flow.

What does the research on PT-141 show?

In the two phase 3 trials behind Vyleesi’s approval, women on bremelanotide reported a modest increase in desire and less distress about low desire than women on placebo. The number of satisfying sexual events didn’t improve significantly.

Earlier studies in men found it could cause erections, but it was never developed further for men.

PT-141 side effects

Nausea is the main side effect: 40% of women in the trials had it, and 8% stopped because of it. Flushing, headache, vomiting and injection-site reactions are also common.

It raises blood pressure for several hours after a dose, so it isn’t used with uncontrolled high blood pressure or heart disease. Some people develop darker patches of skin on the face, gums or breasts, which don’t always fade.

Bremelanotide is legal with a prescription in the US as Vyleesi. PT-141 powders sold online as research chemicals are not approved for human use and aren’t checked for purity or strength.

How do you reconstitute PT-141?

Vyleesi comes in a ready-to-use pen. If you have a powder vial, the calculator above turns the vial size, the bacteriostatic water and a dose into syringe units, and the reconstitution guide explains each step.

See the dosage section below for what is known about doses, with sources.

PT-141 dosage

Vyleesi (bremelanotide) is used as needed, not every day: one injection at least 45 minutes before sexual activity, with limits on how often it can be used.

From the official prescribing information (label). Your prescriber decides your dose and when to change it.

PT-141 doses, with sources
WhenDoseHow often
Each use1.75 mg[1]At least 45 minutes before sexual activity
Limit per dayNo more than 1 dose[1]In 24 hours
Limit per monthNo more than 8 doses[1]Per month
  1. FDA, VYLEESI prescribing information

Medical disclaimer: this dosage information is for education only and comes from the source shown for each row. It is not medical advice and not a recommendation for you. Only a licensed prescriber who knows your health can decide whether PT-141 is right for you and at what dose. Don't start, change or stop a medicine based on this page, and don't use research peptides or unapproved drugs based on trial doses.

PT-141 concentration chart

The concentration of a PT-141 vial depends only on its size and the water you add. Each unit on a U-100 syringe holds one hundredth of a mL.

PT-141 concentration by vial size and water
Vial + waterConcentrationPer unit (U-100)
10 mg + 1 mL10,000 mcg/mL (10 mg/mL)100 mcg per unit (0.1 mg per unit)
10 mg + 2 mL5,000 mcg/mL (5 mg/mL)50 mcg per unit (0.05 mg per unit)
10 mg + 3 mL3,333.33 mcg/mL (3.33333 mg/mL)33.33 mcg per unit (0.03333 mg per unit)

Frequently asked questions

What is PT-141 used for?

As Vyleesi, it is approved for acquired, generalized low sexual desire (HSDD) in premenopausal women. It is also used off-label by men and women for libido and erections, which isn't approved.

Does PT-141 work for men?

Early studies found it could cause erections, including in men who didn't respond to Viagra-type drugs, but it was never approved for men.

How is PT-141 different from Viagra?

Viagra increases blood flow to the penis. PT-141 acts on melanocortin receptors in the brain that affect desire and arousal.

Sources

  1. FDA, VYLEESI (bremelanotide injection) prescribing information
  2. Healio (2019), FDA approves Vyleesi for women with low sexual desire
  3. Wikipedia, Bremelanotide (with cited studies)

Last updated .

More peptide guides and calculators