The straight answer
Here's the honest picture: the treatments that work best for ED aren't peptides at all - they're pills like Viagra and Cialis. That said, ED is one of the few areas where something in our library is genuinely proven: alprostadil, a prescription injection or suppository doctors use when pills don't work. A second one, PT-141 (bremelanotide), has real human data in men but was never approved for them. Everything else here either works only indirectly or hasn't been proven at all.
What actually treats it
The first thing almost every doctor tries is a PDE5-inhibitor pill - sildenafil (Viagra), tadalafil (Cialis), or vardenafil - which work for roughly 7 in 10 men and are cheap and well understood. Just as important, ED is often an early warning sign of heart or blood-vessel disease, diabetes, or low testosterone, so treating the underlying cause matters; when pills aren't enough, proven next steps include alprostadil, vacuum erection devices, and penile implants.
From our library
Compounds here with any tie to erectile dysfunction — rated honestly for this specific use.
- Proven
Alprostadil
Worth a lookThis is the real deal for ED - an FDA-approved prescription drug, backed by strong clinical evidence and medical-society guidelines, that produces a working erection in more than 7 in 10 men who use it. It's given as a penile injection, a urethral pellet, or a gel, and it's the standard option when pills like Viagra don't work or can't be taken. It's not a supplement you buy online; it's prescribed and the first dose is set in a clinic to avoid a prolonged, painful erection.
- Emerging
PT-141 (Bremelanotide)
Worth a lookPT-141 was originally developed as an ED drug for men, and completed human trials did show it can trigger erections through a brain pathway - one study found clear improvement in 34% of men versus 9% on placebo. But that research was never carried to FDA approval for men, so its use here is off-label and understudied, and the 'research' vials sold online aren't the tested product. It's the approved drug Vyleesi only for low sexual desire in women. Worth knowing about, but not a proven or approved ED treatment for men.
- Moderate
hCG
SpeculativehCG doesn't treat ED directly. It only helps in the specific case where your ED is driven by genuinely low testosterone from a hormonal signaling problem - it raises testosterone, and that can improve desire and erections. If your testosterone is normal, it won't fix ED. This is a prescription hormone that needs a diagnosis and blood monitoring, not a general ED fix.
- Early
Melanotan II
Not reallyMelanotan II can cause erections - that's real biology, and it's the discovery that led to the approved drug bremelanotide. But the version sold today is an unregulated, black-market injectable with no verified dose or purity, and it's been linked to kidney damage and melanoma. If you want this brain-pathway effect through a tested route, that's bremelanotide - not this. Not a sensible choice for treating ED.
Bottom line
For most men, a PDE5 pill from a doctor is the answer, and it works about 70% of the time. Among the injectables and peptides here, only alprostadil is a proven ED treatment - and it's a prescription drug for when pills fail, not a supplement.