PT-141, also known as bremelanotide, is a peptide that works by activating melanocortin receptors in the brain to treat sexual dysfunction, such as low libido in women and erectile dysfunction in men. Unlike other medications for erectile dysfunction that affect blood flow, PT-141 directly influences sexual desire and response through the central nervous system. It is administered via subcutaneous injection and can increase sexual desire, physical sensations, and energy, but it does not prevent sexual activity from happening and is not a substitute for adequate time for foreplay.