ResearchSafe

Tadalafil (Tadalafil (Cialis))

Category: Sexual Health. Status: FDA-approved prescription.

A long-acting PDE5 inhibitor prescribed by telemedicine clinics for erectile dysfunction and daily low-dose cardiovascular/prostate health. Its 36-hour duration of effect earned it the nickname "the weekend pill." Also used for pulmonary hypertension and BPH.

How it works

Selectively inhibits phosphodiesterase type 5 (PDE5), preventing cGMP breakdown in smooth muscle. This enhances nitric oxide signaling for vasodilation in penile, pulmonary, and prostate tissue.

Key facts

  • Molecular weight: 389.40 Da
  • Half-life: ~17.5 hours
  • Bioavailability: ~36% oral
  • Storage: Room temperature.

Dosing overview

  • Typical dose: 2.5-5 mg daily or 10-20 mg as needed
  • Frequency: Daily or on-demand
  • Duration: Ongoing
  • Route: Oral tablet

Protocol notes

  • Daily approach: 2.5-5 mg every day for steady readiness plus the cardiovascular/prostate benefits.
  • On-demand approach: 10-20 mg taken at least 30-60 minutes before activity (works for up to ~36 hours).
  • Pick one approach - don't combine daily dosing with large on-demand doses.

Reported benefits

  • Erectile function improvement
  • Cardiovascular health (vasodilation)
  • Prostate health (BPH)
  • Improved exercise capacity
  • Nitric oxide support

Possible side effects

  • Headache
  • Back pain
  • Muscle aches
  • Nasal congestion
  • Flushing
  • Indigestion

Research

  • Daily tadalafil and endothelial function (2022): Daily 5mg tadalafil improved flow-mediated dilation by 30% and reduced arterial stiffness in men over 12 weeks.

Community reviews of Tadalafil

Rated 4.5 out of 5 from 6 community reviews by ResearchSafe members.

  • cycling_chad rated it 4/5 - Genuinely effective after 2 months: Been using Tadalafil for about 2 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
  • deep_science_dee rated it 4/5 - Solid compound with real results: Been using Tadalafil for about 2 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
  • stack_logic_lisa rated it 5/5 - Worth adding to the protocol: Tadalafil has been a worthwhile addition. I am data-driven and tracked relevant markers before, during, and after. The improvement is measurable and correlates with the intervention timeline. What sets this apart from some compounds I have tried is the consistency. Benefits did not fluctuate wildly or disappear. They built up and maintained. That gives me confidence in the mechanism. Tolerance has been excellent. Nothing in my bloodwork or subjective experience raised any flags. This is the kind of compound that does its job quietly without causing problems. Exactly what you want.
  • peptide_path_pam rated it 5/5 - Noticed clear benefits within weeks: Added Tadalafil to my protocol about 4 months ago and it has earned its place. The benefits became noticeable around week 2-3 and have been consistent since. What I appreciate about this compound is the predictability. It does what the research suggests it should do, at roughly the timeline you would expect. No surprises, no dramatic swings, just steady improvement. No notable side effects to report at my dose. Sourcing is always the challenge with research compounds, insist on third-party testing. Storage and reconstitution per standard protocols. Plan to continue.
  • student_midwest306 rated it 5/5 - Quietly fixed the part that mattered most: For me, tadalafil made intimacy feel normal again within the first week, which was the main thing I wanted at 56 while juggling grad work and training in the Netherlands. After about 3 weeks, that reliable response stayed there. I also noticed a bit easier exercise breathing, maybe?
  • grinder265 rated it 4/5 - Helped my long-run recovery, with a weird headache tax: I’m 26, on the East Coast, and between ultramarathon training and a pretty stupid work schedule, I wanted something that might help blood flow and keep things solid on rough days. I ran tadalafil for about 8 weeks. For me, it seemed to make erections way more reliable, and my legs felt a little less dead after hard long runs. The one caveat was a dull headache the first couple weeks, then it mostly settled down.

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Community discussions about Tadalafil

Research and educational reference only. Not medical advice.