What is the recommended PT-141 dosage?

PT-141 dosing varies by experience level. Beginners typically start at 500mcg as needed, moderate users at 1000mcg as needed, and aggressive protocols use 1750mcg as needed.

How do you reconstitute PT-141?

PT-141 typically comes in 10mg vials. Add 2mL of bacteriostatic water to the vial. Use our free calculator for exact syringe units based on your desired dose.

What is the half-life of PT-141?

The half-life of PT-141 is ~2.7 hours. This determines how frequently you need to dose for consistent blood levels.

PT-141

Sexual HealthInjectionFDA ApprovedGrade B~2.7 hours half-life

FDA-ApprovedMC4R AgonistSexual HealthOn-Demand Dosing

Benefits

FDA-approved (as Vyleesi) for sexual dysfunction

Works at the brain level — increases desire, not just blood flow

Effective for both men and women

On-demand dosing (45-60 min before activity)

Does not require daily dosing

Half-Life

~2.7 hours

Route

Injection

Frequency

As needed

Vial Sizes

10mg

BAC Water

2mL

Safety Grade

Grade B

Open PT-141 Dosage Calculator

Calculate exact syringe units for your vial and dose

About PT-141

PT-141 (Bremelanotide) is the only FDA-approved peptide for hypoactive sexual desire disorder — marketed as Vyleesi. Unlike Viagra/Cialis, which work on blood flow, PT-141 works in the brain by activating melanocortin-4 receptors (MC4R) to increase sexual desire and arousal. It works for both men and women and addresses desire, not just mechanics.

Who Should Consider PT-141

Premenopausal women with hypoactive sexual desire disorder (HSDD)
Men with erectile dysfunction unresponsive to PDE5 inhibitors
Individuals seeking desire-based (not blood-flow-based) treatment
Patients who cannot tolerate PDE5 inhibitors

What to Expect

First dose

45-60 min

Onset of effects within 45-60 minutes of SC injection. Nausea is most common on first use. Flushing and warmth may occur as MC4R activation begins.

Doses 2-4

Nausea typically decreases with repeated use. Patients learn optimal timing relative to activity. Effects last approximately 6-12 hours after dosing.

Doses 5-8

first month

Side effect profile stabilizes. Patients establish personal effective dose within the 0.5-1.75mg range. On-demand pattern becomes routine.

Ongoing use

Consistent on-demand use as needed, up to 8 doses per month. No tachyphylaxis observed in clinical trials lasting 24 weeks. Blood pressure should be monitored periodically.

Dosing Protocol

Level	Dose / Injection	Frequency
Beginner	500mcg	As needed
Moderate	1mg	As needed
Aggressive	1,750mcg	As needed

Note: MC4R agonist (Bremelanotide). Dose 45-60 min before activity. Max 8 doses/month. Nausea is common.

Pharmacokinetics

Half-Life

2.7h

Bioavailability

SC: ~100%

Tmax

~1 hour

Data Confidence

high

Source: FDA Prescribing Information (Vyleesi), Section 12.3

Pharmacokinetics — Active Dose Over Time

t½ = ~2.7 hours

After 1 half-life (3h): 50% remainsAfter 2 half-lives (5h): 25% remainsAfter 3 half-lives (8h): 12.5% remains

At a 1mg dose: 50% = 500mcg remaining after 3h. Recommended frequency: As needed.

Disclaimer: This curve is a simplified first-order exponential decay model. Actual pharmacokinetics vary based on injection site, individual metabolism, body composition, and other factors. Half-life values are approximate and based on available preclinical and clinical literature. Many research peptides lack formal human pharmacokinetic studies. This is for educational purposes only — not medical advice.

Side Effects

Nausea (most common — can be significant). Flushing, headache. Temporary blood pressure elevation. Limit to 8 doses per month.

Contraindications

Uncontrolled hypertension or known cardiovascular disease
Pregnancy or breastfeeding
Known hypersensitivity to bremelanotide or any excipients
Concurrent use with oral naltrexone-containing products
Hepatic impairment (moderate to severe) — increased drug exposure

Drug Interactions

Naltrexone (oral) — bremelanotide significantly decreases naltrexone systemic exposure; avoid concurrent use with naltrexone-containing products for alcohol or opioid addiction
Indomethacin — bremelanotide may reduce absorption of co-administered indomethacin
Antihypertensives — monitor blood pressure; bremelanotide causes transient BP elevation
Other oral medications — bremelanotide may slow gastric emptying and delay absorption of co-administered oral drugs

Molecular Profile

Amino Acids

Molecular Weight

1,025.18 Da

Structure

Cyclic

Sequence

DHFRWK

HydrophobicPolarPositiveNegativeSpecial

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