Tadalafil is a medication primarily known for treating erectile dysfunction (ED), benign prostatic hyperplasia (BPH) symptoms, and pulmonary arterial hypertension (PAH). It belongs to a class of drugs called phosphodiesterase-5 (PDE5) inhibitors. Originally marketed under the brand name Cialis, it is available in various strengths and formulations. Tadalafil distinguishes itself from other PDE5 inhibitors by its longer half-life, allowing for effects lasting up to 36 hours, earning it the nickname "the weekend pill." Its use for ED involves assisting in achieving and maintaining an erection by increasing blood flow to the penis following sexual stimulation. For BPH, it helps relax muscles in the prostate and bladder, improving urinary symptoms. In PAH, it relaxes blood vessels in the lungs, reducing pressure and improving exercise capacity (FDA label, DrugBank).
Deep dive
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Known interactions
Category rule: supplement × medication
Note
Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).
Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist.
Category rule: vitamin × medication
Note
Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).
Specific pairs are checked against a licensed source; confirm with your provider.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Compound-pair rule
Caution
PDE5 inhibitors add to the blood-pressure-lowering effect of antihypertensives.
Start PDE5 at the lowest effective dose and monitor for hypotension.
Frequently asked
Sources referenced
- FDA label
- DrugBank
- PubChem
- Mayo Clinic
- MedlinePlus
- NIH Office of Dietary Supplements (NIH ODS)
- Cochrane Library
- Examine.com
- European Medicines Agency (EMA) Summary of Product Characteristics (SmPC)
Stackwise compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician.
Related compounds
Others in the medication category or studied for the same goals.
