Tadalafil
What is tadalafil?
Tadalafil, sold as Cialis, is a prescription drug that relaxes smooth muscle in blood vessels and the prostate. It is approved at daily low doses for erectile dysfunction and an enlarged prostate. Some longevity enthusiasts take 2.5 to 5 mg a day for blood flow and vessel health, which is an off-label use without trial evidence.
Listed here because well-known people have tried it on themselves. Trying something is not recommending it; each entry says whether the person tells others to do it.
Who has tried it
Tried by 1 person we can source: 1 kept.
Kept
Bryan JohnsonEntrepreneur, founder of BlueprintBlueprint (Bryan Johnson)
Started Jun 2023 · Does not recommend it to others
Takes 5 mg a day for blood vessel function and inflammation, after starting at 2.5 mg in June 2023 as a longevity and bladder health intervention.
“enhances endothelial function, reduces inflammation, and potentially protects against age-related cardiovascular and metabolic decline”
Bryan Johnson, Bryan's Protocol (checked November 2026) · Status checked November 1, 2026 · Suggest a correction
What the evidence shows
For its approved uses the evidence is good. Daily tadalafil improved urinary symptoms of an enlarged prostate at 2.5 to 20 mg [1] and erectile function at 2.5 and 5 mg across six trials [2].
The longevity case rests on observational data. Swedish men given erectile dysfunction drugs after a heart attack had 33% lower mortality [3], and in UK records men starting these drugs had an 18% lower rate of Alzheimer disease [4]. A US Medicare analysis of patients with pulmonary hypertension found no link with Alzheimer risk [5], and men who get these prescriptions are often healthier to begin with.
No trial has tested daily tadalafil for aging, heart disease prevention or dementia in healthy men.
Safety
- Tadalafil is a prescription drug approved for erectile dysfunction, an enlarged prostate and pulmonary hypertension. Daily use for longevity is off-label.
- It must never be combined with nitrates or riociguat, because blood pressure can drop dangerously. Alpha-blockers also need care.
- Common side effects are headache, flushing, indigestion, back pain and nasal congestion.
- Seek care at once for an erection lasting over 4 hours or sudden loss of vision or hearing; a review found no clear rise in a rare optic nerve stroke, but case reports exist [@penedones2020].
Common questions
Does Bryan Johnson take tadalafil?
Yes. As of November 2026 his published protocol lists 5 mg a day, for blood vessel function and inflammation. He started at 2.5 mg in June 2023. His page jokes that readers who credit it for his results can match his dose, but lists it as his own prescription.
Does daily tadalafil help you live longer?
Nobody knows. Men prescribed these drugs after a heart attack lived longer in Swedish records [3], but such studies cannot rule out that healthier men get the prescriptions. No trial has tested it for aging.
Does tadalafil lower dementia risk?
What dose of tadalafil is used daily?
Approved daily doses are 2.5 or 5 mg for erectile dysfunction and 5 mg for an enlarged prostate [1]. Any dose should come from a prescriber.
Sources
- 1.Roehrborn CG, McVary KT, Elion-Mboussa A, et al. Tadalafil administered once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a dose finding study. J Urol, 2008. doi:10.1016/j.juro.2008.06.079
- 2.Porst H, Gacci M, Büttner H, et al. Tadalafil once daily in men with erectile dysfunction: an integrated analysis of data obtained from 1913 patients from six randomized, double-blind, placebo-controlled, clinical studies. Eur Urol, 2014. doi:10.1016/j.eururo.2013.09.037
- 3.Andersson DP, Trolle Lagerros Y, Grotta A, et al. Association between treatment for erectile dysfunction and death or cardiovascular outcomes after myocardial infarction. Heart, 2017. doi:10.1136/heartjnl-2016-310746
- 4.Adesuyan M, Jani YH, Alsugeir D, et al. Phosphodiesterase Type 5 Inhibitors in Men With Erectile Dysfunction and the Risk of Alzheimer Disease: A Cohort Study. Neurology, 2024. doi:10.1212/WNL.0000000000209131
- 5.Desai RJ, Mahesri M, Lee SB, et al. No association between initiation of phosphodiesterase-5 inhibitors and risk of incident Alzheimer's disease and related dementia: results from the Drug Repurposing for Effective Alzheimer's Medicines study. Brain Commun, 2022. doi:10.1093/braincomms/fcac247
- 6.Penedones A, Alves C, Batel Marques F. Risk of nonarteritic ischaemic optic neuropathy with phosphodiesterase type 5 inhibitors: a systematic review and meta-analysis. Acta Ophthalmol, 2020. doi:10.1111/aos.14253