Pepdexpepdex
← All compounds

Tadalafil

Cialis / aminotadalafil / nortadalafil (unregulated analogs) · PDE5 inhibitor

Research reference only. Pepdex does not sell, supply or track this compound, and nothing here is guidance to use it — this page exists so the evidence and the risks are visible.

What it is

A prescription PDE5 inhibitor developed for erectile dysfunction and BPH, with a much longer half-life (~17.5 h) than sildenafil. Increasingly researched at low daily use for endothelial function and blood-pressure effects, which is why it shows up in biohacking stacks far beyond ED.

What human evidence shows

Strong trial evidence for ED and BPH — this is one of the best-evidenced compounds on this list, with FDA approval and decades of data. Daily low-dose regimens are an approved prescribing pattern. Evidence for gym "pump"/performance use is thin and mostly mechanistic; the endothelial-health signal is real but studied in clinical populations, not healthy young men.

Risks

Headache, flushing, nasal congestion, back pain and muscle aches (more than sildenafil, because of the long half-life). Dangerous interaction with nitrates — the combination can drop blood pressure catastrophically. Priapism is rare but a surgical emergency. New visual or hearing changes warrant prompt medical assessment. Products from outside lawful channels can vary widely in actual content.

Legal status

US: prescription-only (not scheduled). Products offered outside lawful prescription channels may be falsified or mislabeled.

Evidence base

S3,181 research papers
established literature

Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.

phase 3/4
24
randomised
353
reviews
119
human trials
449

Counts are of published papers, not distinct trials, and measure how much research exists — not whether this works or is safe for you.

Research (12)

Turn Tadalafil into a plan that's yours

The info above is free. Membership makes it personal, the Coach answers questions about your exact stack, the Stack tracks it for you, and the Verified Sources shows you how to vet what you buy.

  • AI Coach, ask anything about your stack. It does the dosing math, flags interactions, and tells you what to do next.
  • Personal Stack, save your protocol, track it across devices, log doses, get a heads-up before a vial runs out.
  • Verified Sources, the vetted reference for checking quality and sourcing, members only.
Become a member, from $4.99/week

Cancel anytime · or save with $59.99/yr · Coach + Stack included

Where next