Podcast episode 21 (in German)
Tadalafil (Cialis): A sex pill for the brain? Prostate, blood pressure & head fact-checked
July 12, 2026
Tadalafil is known as Cialis, but its real talent is greater than its reputation: it keeps blood vessels throughout the body wider for longer. That is why urologists, cardiologists and brain researchers are now interested in the molecule.
What it is about
Tadalafil is a PDE5 inhibitor from the same family as sildenafil. It blocks the enzyme that breaks down the vessel-relaxing messenger cGMP, thus amplifying a signal the body sends itself. Unlike sildenafil, it acts for a very long time, which makes a low-dose daily intake possible in addition to on-demand use. The episode goes through the three approvals, explains why urologists value it for an enlarged prostate, and looks at the endothelium, training and the open question of whether it protects aging brain vessels. The conclusion is an inexpensive, long-tested prescription medicine with one hard rule: never together with nitrates.
Key points
- Tadalafil came onto the market in 2003 as Cialis and is now available as a generic; in Germany it is available only on prescription.
- The half-life is 17.5 hours and the effect lasts up to 36 hours, whereas sildenafil works for 4 to 6 hours.
- It has 3 approvals: erectile dysfunction, benign prostatic enlargement and, under another name, pulmonary hypertension; this range alone points to a vascular drug.
- According to a 2015 review by Yokoyama and colleagues, daily intake improves prostate symptoms similarly to classic prostate drugs and additionally strengthens erectile function.
- For the brain, the data are mixed: the PASTIS trial in 2022 found no clear improvement in cerebral blood flow, the ETLAS-2 trial in 2025 found measurable effects on cerebrovascular function.
- The mechanism rests on the discovery of nitric oxide as a signaling molecule, which was awarded the Nobel Prize in 1998.
Where the data stop
Large observational studies found in some cases markedly fewer Alzheimer’s diagnoses among users of PDE5 inhibitors, but that is correlation, not proof, and the controlled trials are inconsistent. Its use as an endothelium and pump tool in training rests on the mechanism and on user reports, not on dedicated studies for this purpose.
Tadalafil must never be combined with nitrates such as nitroglycerin, and this also applies to poppers: blood pressure can drop dangerously. Common, usually mild accompanying effects are headache, a stuffy nose and heartburn. Anyone who has heart problems or strongly fluctuating blood pressure or takes blood pressure medication should clarify its use with a physician. Obtain it only on prescription and from a pharmacy.
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Published on July 12, 2026.
The topic in the database
- The proven, approved erectile dysfunction drug (Cialis) – as a PDE5 inhibitor it improves blood flow and also helps with prostate complaints and pulmonary…Tadalafil
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-09.