PT-141 (Bremelanotide)

Common questions about PT-141 (Bremelanotide)

What is PT-141 (bremelanotide)?

PT-141, also known as bremelanotide, is a synthetic melanocortin receptor agonist that acts on MC4 receptors in the central nervous system to increase sexual arousal and desire. The molecule is FDA-approved as Vyleesi (bremelanotide injection) for hypoactive sexual desire disorder (HSDD) in premenopausal women. The PT-141 Rx Peps Direct prescribes is not that branded product: the pharmacy compounds it under Section 503A as a patient-specific prescription, a different regulatory pathway than FDA approval of the specific compounded preparation. PT-141 is also used off-label in men for libido and erectile function support, particularly in patients who do not respond well to PDE5 inhibitors (sildenafil, tadalafil) or who want a non-vascular mechanism.

Does PT-141 work for libido and erectile function?

Yes. The mechanism is central (brain-mediated) rather than vascular, which is why PT-141 works in some patients who do not respond to sildenafil or tadalafil. Onset is typically 30 to 60 minutes post-injection. Effects last 4 to 8 hours. The Vyleesi trial data established efficacy for HSDD in women; men using PT-141 off-label commonly report improvements in libido and erectile response.

How is PT-141 dosed?

The Rx Peps Direct starting dose is 20 units (0.4 mg) on a U-100 insulin syringe, injected subcutaneously 45 minutes before sexual activity, as needed. Your provider may step you up to 50 units (1 mg), and the maximum is 88 units (1.75 mg). Leave at least 24 hours between doses and use no more than 8 doses a month, counting the injection and the nasal spray together. For comparison, the Vyleesi-approved dose for women is 1.75 mg subcutaneous as needed (no more than 8 doses per month and no more than 1 dose in 24 hours). A licensed U.S. 503A compounding pharmacy compounds the vial at 2 mg/mL, so 20 units is 0.2 mL.

How is PT-141 injected?

Subcutaneous injection into the abdomen, upper outer thigh, or back of the upper arm using a 31-gauge, 5/16-inch (8 mm) needle on a U-100 insulin syringe. Sterile syringes are included with every Rx Peps Direct shipment. Inject 45 minutes before sexual activity.

Are there side effects with PT-141?

The most common side effects are nausea (most common, especially with the first few doses), facial flushing, headache, and transient hyperpigmentation at the injection site or on the gums. PT-141 raises blood pressure modestly; patients with uncontrolled hypertension should not use it. Avoid concomitant use with cardiac stimulants. If nausea is severe, your provider may prescribe ondansetron PRN.