PT-141

Bremelanotide · Vyleesi · S-tier (Dr. Alex Tatem) · Strong evidence

Works on desire in the brain rather than blood flow, which makes it different from Viagra. It’s approved for women, and Dr. Tatem says it works in men too, though it was never developed for them.

Dr. Tatem’s take

Rated the melanotan family S-tier: “extremely effective at what they do” with “an extremely positive safety profile”, though he jokes about the nausea. Note that melanotan II (the tanning peptide) is a different, unapproved compound.

In Dr. Tatem’s tier list

• “One of my absolute favorite compounds,” mostly for the story behind it.
• Melanotan was investigated as an injectable tanning agent at the University of Arizona in the 1980s–90s: activating the melanocortin receptor increases melanin and causes a tan.
• The urban legend: a lead researcher accidentally injected himself with double the investigational dose of melanotan II and got an eight-hour erection plus severe nausea — a mishap that pointed to the sexual-function potential.
• That line of work led to PT-141 (bremelanotide, Vyleesi), now prescribed for low sexual desire in women. He says it works in men too, but it was never developed for them.
• Verdict on the melanotan family: “extremely effective at what they do” with “an extremely positive safety profile” — S tier.

History & background

Melanotan I was first described in 1980 by Sawyer, Hruby, Hadley and colleagues at the University of Arizona; the more potent, cyclic melanotan II followed and was tested for erectile dysfunction in a small 1998 study. Palatin Technologies developed bremelanotide (PT-141), a metabolite-derived analog of melanotan II, through the 2000s.

Nasal PT-141 was dropped after blood-pressure concerns; the injectable version was approved by FDA as Vyleesi in June 2019 for acquired, generalized low sexual desire in premenopausal women.

Benefits

• Improved desire and reduced distress in two phase 3 trials (n=1,267).

Risks

• Nausea (about 40%), flushing, headache.
• Temporary rise in blood pressure.
• Skin darkening with repeated use.
• Don’t use with uncontrolled high blood pressure or heart disease.

Dosing protocols (informational, labeled by evidence)

• Clinical trial / label: FDA label – Vyleesi (premenopausal HSDD) — 1.75 mg, SubQ (abdomen/thigh), As needed, ≥45 min before activity; max 1 dose per 24 h, ≤8 per month, Stop after 8 wk if no benefit
• Community (bro science): Community use (incl. men) — 0.5–2 mg, SubQ, As needed, As needed

Status: FDA-approved (Vyleesi, 2019) for low sexual desire (HSDD) in premenopausal women. Named in August 2026 warning letters to research-peptide sellers.

Grade and commentary: Dr. Alex Tatem. Watch: Truth About More Popular Peptides (What Works, What’s Overhyped) | Peptide Tier List pt.2. Subscribe: @DrAlexTatem.