PT-141 is distinctive in this library because, unlike most research peptides, it
has an approved pharmaceutical form. This monograph covers the pharmacology and
the trial record.
Chemical identity & structure.
PT-141, generic name bremelanotide, is a synthetic cyclic heptapeptide. It
was developed from melanotan II, an earlier melanocortin-system peptide;
bremelanotide is a related but distinct molecule with a different activity
profile. Its cyclic structure contributes to its receptor selectivity and
stability.
Mechanism of action.
PT-141 is a melanocortin-receptor agonist, acting principally at the MC4 receptor
(with activity at MC3R as well). This is a fundamentally different mechanism from
the vascular drugs used for sexual dysfunction — PT-141 acts centrally, in the
nervous system, on pathways involved in sexual desire and arousal, rather than on
blood flow. MC1R activity in the melanocortin family is also why this class is
associated with effects on skin pigmentation.
Key research findings.
Bremelanotide was studied in clinical trials for hypoactive sexual desire
disorder (HSDD) in premenopausal women and was found to increase measures of
sexual desire and reduce associated distress. The trials also documented its
side-effect profile, including nausea, flushing, and transient blood-pressure
changes.
The research / citation base.
Bremelanotide is FDA-approved (brand name Vyleesi) for HSDD in premenopausal
women, on the strength of published Phase 3 trials. That gives PT-141 a real
human evidence base for its approved indication. Uses outside that indication are
not supported by the same level of evidence.
In the two identical phase 3 RECONNECT trials (Kingsberg and colleagues, 2019), 1,267 premenopausal women with hypoactive sexual desire disorder were randomized 1:1 to 24 weeks of bremelanotide 1.75 mg administered subcutaneously as needed or placebo (PubMed).
Research-grade PT-141 is supplied as a lyophilized powder.
Quality & sourcing notes.
A batch-specific COA should confirm identity by mass spectrometry and HPLC
purity. A specific market hazard: PT-141 and melanotan II are sometimes confused
or substituted for one another despite being different molecules with different
profiles — confirm which compound a COA actually describes.
*Research-use note: Educational summary of published research. Bremelanotide is a
prescription drug; this monograph is research context only and is not medical
advice.*
