Both PT-141 and sildenafil (also known by the brand name Viagra) help treat sexual dysfunction. The key difference is in how they work.
Sildenafil is a vasodilator, meaning that it works by increasing blood flow to the penis. One of the causes of erectile dysfunction is reduced blood flow to the penis. Sildenafil causes the blood vessels in your penis to dilate, allowing you to have an erection.
PT-141 is a peptide that works by acting directly on your brain. PT-141 allows you to enjoy sexual arousal; hence, it does not give you an erection just for the sake of it, when taken at the right dose.
According to the scientists who developed this medication, it has “no undesirable side effects at the therapeutic dose used.” This is different from sildenafil, which may cause a decrease in blood pressure (since it causes your blood vessels to dilate). Around 50% of men stop using sildenafil tablets over time.
In summary, PT-141 works by increasing sexual arousal in the brain and sildenafil works by increasing blood flow to the penis.
References
Hadley ME. Discovery that a melanocortin regulates sexual functions in male and female humans. Peptides. 2005;26(10):1687-1689. doi:10.1016/j.peptides.2005.01.023
Rosen RC, Diamond LE, Earle DC, Shadiack AM, Molinoff PB. Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra. Int J Impot Res. 2004;16(2):135-142. doi:10.1038/sj.ijir.3901200
