melanocortin-4 receptor agonist · studied for low sexual desire in premenopausal women (FDA approved), erectile response in men (phase 2 only)

PT-141 dosage

PT-141 is bremelanotide, the drug sold as Vyleesi. The FDA dose is 1.75 mg subcutaneous at least 45 minutes before sex, no more than one dose in 24 hours and no more than 8 a month. In men, a published dose study saw erections above 1 mg and used 4 and 6 mg in men who failed sildenafil. Research vials are 10 mg; most people use 0.5 to 2 mg per dose. Nausea is the main side effect: 40% in the trials.

By the Peptide Calculations editors · Updated 2026-10-19

1.75 mgper dose

Basis: FDA label. subcutaneous, abdomen or thigh, at least 45 minutes before sexual activity; max 1 per 24 hours and 8 per month; stop after 8 weeks if no benefit

How often: as needed, no more than once in 24 hours; label caps at 8 doses a month
When: 45 minutes to 4 hours before; effects last several hours and can carry into the next day
How long: as needed only; no daily use
Route: subcutaneous, abdomen or thigh
Storage: lyophilized: fridge or freezer; reconstituted: fridge, use within 4 weeks (commonly reported); Vyleesi pens are stored at room temperature

Dose ranges by source

Range	Per	Basis	Note
1.75 mg	dose	FDA label	subcutaneous, abdomen or thigh, at least 45 minutes before sexual activity; max 1 per 24 hours and 8 per month; stop after 8 weeks if no benefit
1 mg to 6 mg	dose	clinical trial (Rosen, Diamond et al. 2004, Int J Impot Res; healthy men 0.3 to 10 mg, ED patients 4 or 6 mg)	erectile response was significant above 1 mg; 4 and 6 mg both worked in men with inadequate sildenafil response
0.5 mg to 2 mg	dose	commonly reported	start at 0.5 mg to test nausea, then 1 to 2 mg; taken 1 to 4 hours before

PT-141 dose to units chart

10 mg vial + 2 mL bacteriostatic water = 5 mg/mL (50 mcg per unit on a U-100 insulin syringe). 10 mg + 2 mL = 5 mg/mL, so 1 mg = 0.2 mL = 20 units, 1.75 mg (the label dose) = 35 units and 0.5 mg = 10 units.

Dose	mL	Units (U-100)	Doses per vial
1 mg	0.2	20	10
1.75 mg	0.35	35	5
2 mg	0.4	40	5

Different vial or water? Full 10 mg + 2 mL table or set your own numbers below.

Side effects

nausea (40% on the label, 8% quit because of it)
flushing (20%)
injection site reactions (13%)
headache (11%)
vomiting
transient blood pressure rise of about 6 mmHg for a few hours
darkening of skin, gums or freckles with repeated use (focal hyperpigmentation)

Before you start. The label contraindicates uncontrolled high blood pressure and known cardiovascular disease, and warns against more than one dose in 24 hours because the blood pressure effect adds up. It slows gastric emptying and can cut absorption of oral drugs taken near it, including naltrexone. Men dosing 4 to 6 mg are far above the label and nausea climbs with dose. Not medical advice. Talk to a clinician and start low.

PT-141 dosage questions

PT-141 dosage for men?

There is no approved male dose. The 2004 dose study found significant erections above 1 mg and used 4 and 6 mg in men who did not respond to sildenafil. Most men start at 0.5 to 1 mg and settle at 1 to 2 mg, because nausea rises fast above that. The female label dose, 1.75 mg, is a sensible ceiling to start under.

How many units of PT-141 is 1 mg?

With 10 mg in 2 mL (5 mg/mL), 1 mg is 20 units on a U-100 syringe. 1.75 mg is 35 units, 2 mg is 40 units. If you used 1 mL of water instead, halve those numbers.

How long before does PT-141 take to work?

The label says inject at least 45 minutes before sex. Users report the strongest window at 1 to 3 hours and effects lasting 6 to 12 hours, sometimes into the next day. Do not redose within 24 hours.

How often can you take PT-141?

At most once in 24 hours and, on the label, no more than 8 doses a month. More frequent dosing raises the chance of blood pressure effects and skin darkening.

Does PT-141 raise blood pressure?

Yes, briefly. In the trials systolic pressure rose about 6 mmHg and heart rate dropped up to 5 beats per minute, peaking 2 to 4 hours after the dose and back to normal within 12 hours. People with uncontrolled hypertension or heart disease should not use it.

Sources

Brands we recommend for PT-141. We are independent and have no affiliation with any brand: no affiliate links, no referral codes, no paid placements. These are the suppliers whose testing and certificates hold up when we check them.

Licensed Peptides two accredited labs on every lot, certificates public, card and Apple Pay checkout
Core Peptides long track record, public certificates, wide catalog
Ascension Peptides public third-party testing, clear pricing

This page is an educational summary of published labels, trials and commonly reported use. It is not medical advice and does not replace a clinician.