PT-141

Sexual function

Also known as Bremelanotide, Vyleesi

A melanocortin receptor agonist for low sexual desire. FDA approved.

How it works

An analogue of alpha-MSH acting at melanocortin receptors in the central nervous system, principally MC4R. It works through brain pathways governing sexual desire rather than through blood flow, which is what distinguishes it from PDE5 inhibitors.

Subcutaneous

In the body

Half-life

2.7 hours

Time to peak

1 h

90% gone after

9 h

Builds up to

1×

Steady state after about 13.7 h at as needed, at least 45 minutes before activity.

Shape of a single dose, modelled as one compartment with first-order absorption. The peak is normalised to 100% because bioavailability and volume of distribution are not published for most of these compounds.

About 2.7 hours after subcutaneous injection.

What happens, and when

0 min, 1 hAbsorbing. The label advises dosing at least 45 minutes ahead.
1 h, 3 hPeak levels. Nausea, if it happens, is most likely here.
3 h, 16 hClearing. Blood pressure rises transiently and heart rate falls in this window.

Doses

1.75 mgas needed, at least 45 minutes before activityApproved label

1.75 mg subcutaneously in the abdomen or thigh. No more than one dose in 24 hours and no more than eight doses per month.

Vial sizes

1.75 mg10 mg

Side effects

Nausea, often on the first dose, it affected about 40% in trials and led 8% to stop
Flushing and injection site reactions
Headache
Transient rise in blood pressure with a fall in heart rate, peaking in the first hours
Darkening of the skin or gums with repeated use, more likely in people with darker skin

Cautions

Uncontrolled high blood pressure or known cardiovascular disease.
Not for premenopausal women who are pregnant.

Status

FDA approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women.

Sources

Vyleesi prescribing information

Reference information for personal record-keeping. Not medical advice, and not a recommendation to use any of these compounds.