How to Reconstitute PT-141 (Bremelanotide): Step-by-Step Guide

Does bremelanotide come as a powder you mix?

No. The FDA-approved bremelanotide product is Vyleesi, a 1.75 mg subcutaneous injection in a prefilled autoinjector pen, prescription only, approved June 21, 2019 under NDA 210557 [1][4]. The label describes a prefilled pen that delivers a fixed dose into the abdomen or thigh, with no concentration to calculate [1].

What is in a PT-141 vial, then?

Products sold as PT-141 peptide, whether compounded or labeled for research use, are not Vyleesi and are not FDA-approved drugs [2]. Compounded drugs are not reviewed by FDA for safety, effectiveness or quality before marketing [3]. Bremelanotide does not appear on FDA's list of bulk substances that may present significant safety risks (content dated April 22, 2026), nor among the six peptides in HHS's October 2026 draft enforcement-discretion policy [5][6][7]. The Vyleesi label covers only the prefilled pen, so it gives no reconstitution, diluent or concentration steps for a vial [1].

What the Vyleesi label says

The dose is 1.75 mg subcutaneously in the abdomen or thigh, as needed, at least 45 minutes before anticipated sexual activity [1]. The label says not to administer more than one dose within 24 hours, that more than 8 doses per month is not recommended, and to stop after 8 weeks if there has been no improvement [1]. The label also states that the duration of effect after a dose is unknown [1].

The approved use is premenopausal women with acquired, generalized HSDD; it is not indicated for postmenopausal women, for men, or to enhance sexual performance [1]. After a 1.75 mg dose, median time to peak concentration is about 1 hour and mean terminal half-life about 2.7 hours, range 1.9 to 4.0 [1].

What the label says to expect

In the pooled phase 3 trials (1,247 women; Vyleesi n=627, placebo n=620): nausea 40.0% vs 1.3%, flushing 20.3% vs 0.3%, injection site reactions 13.2% vs 8.4%, headache 11.3% vs 1.9% [1]. Eight percent of patients stopped the trials because of nausea [1].

Each dose transiently raises blood pressure: maximal increases of 6 mmHg systolic and 3 mmHg diastolic, peaking 2 to 4 hours after the dose, usually back to baseline within 12 hours [1]. In an ambulatory study of 127 premenopausal women dosed daily for 8 days, mean daytime increases were 1.9 mmHg systolic and 1.7 mmHg diastolic [1]. Vyleesi is contraindicated in uncontrolled hypertension or known cardiovascular disease [1]. Focal hyperpigmentation was reported by 1% of patients taking up to 8 doses a month, versus none on placebo [1].