PT-141 (Bremelanotide)

Quickstart highlights

Dosing & reconstitution guide

Standard protocol (2 mL = 5 mg/mL)

A 10 mg vial dissolved in 2 mL bacteriostatic water gives a concentration of 5 mg/mL. Calculate your own dilution →

Reconstitution steps

1. Let the vial reach room temperature and wash your hands.
2. Disinfect both rubber stoppers with an alcohol swab.
3. Draw up 2 mL of bacteriostatic water.
4. Inject the water slowly down the glass wall, not directly onto the powder.
5. Swirl gently until clear — never shake.
6. Label the vial with date and concentration and refrigerate.

Supplies needed

• PT-141 (Bremelanotide) vial (10 mg)
• Bacteriostatic water
• Mixing syringe (1–3 mL) and U-100 insulin syringes
• Alcohol swabs and sharps container

Protocol overview

Dosing protocol in research

Values as described in literature and research protocols; not dosing advice.

Storage instructions

• Lyophilised (powder): cool, dry and dark; long-term at −20 °C.
• After reconstitution: refrigerator at 2–8 °C, use within ~4 weeks.
• Avoid repeated freezing and thawing.

Important notes

How this works

PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide. It is an active metabolite of Melanotan II but lacks the potent pigmentation properties of its predecessor. In the US, it is FDA-approved under the brand name Vyleesi for treating hypoactive sexual desire disorder (HSDD) in premenopausal women.

This peptide acts as a melanocortin receptor agonist, specifically targeting MC3R and MC4R in the central nervous system. Activation of these receptors in brain regions like the nucleus accumbens triggers dopamine release, which is linked to motivation and sexual arousal. Unlike compounds like sildenafil, which locally affect blood flow via nitric oxide, PT-141 operates through neurological pathways in the brain. It has a half-life of approximately 2.7 hours, with effects typically emerging several hours after administration. Activity at the MC1R receptor explains side effects such as skin pigmentation and changes in blood pressure.

Research on bremelanotide includes multiple phase 3 clinical trials, which supported its US approval in 2019. In these trials, women reported increased sexual desire and reduced associated distress. Although originally studied as a nasal spray for erectile dysfunction in men, the subcutaneous route is now preferred due to superior bioavailability. It is not currently on the WADA prohibited list, though its use for athletic performance has not been studied. Open questions remain regarding long-term safety with daily use and its efficacy in specific medical subgroups.

Potential benefits & side effects

Effects described in research

• Increased sexual desire (phase 3, women)
• Independent of vasodilation

Common side effects

• Nausea
• Flushing
• Headache
• Temporary blood pressure rise

Nausea is the most frequently reported side effect, occurring in approximately 40% of users, often shortly after administration. Other observed effects include flushing, headache, and a transient increase in blood pressure. Repeated use may lead to skin or gum hyperpigmentation, which is generally reversible upon discontinuation.

Contraindications

• Pregnancy or breastfeeding
• Active or prior cancer
• Under 18 years of age
• Uncontrolled hypertension or cardiovascular disease

Lifestyle factors

• Keep a log of doses, timing and observed effects.
• Adequate sleep, hydration and a stable diet.

Injection technique

• Choose a site with subcutaneous fat: abdomen (5 cm from the navel), thigh or back of upper arm.
• Disinfect, pinch a skin fold and insert at a 45–90° angle.
• Inject slowly, wait 5 seconds and withdraw.
• Rotate sites and use each needle once.

Recommended source

Quality varies widely between suppliers. Look for an independent HPLC/MS lab report per batch, purity ≥ 98% and clear storage and shipping conditions.

As a reference we use the PT-141 (Bremelanotide) from PeptideWinkel, which publishes lab reports per batch.

Frequently asked questions