Tadalafil: What It Is, How It Works, and When to Use It

Tadalafil is a prescription drug most people know for treating erectile dysfunction (ED). It also treats benign prostatic hyperplasia (BPH) and pulmonary arterial hypertension (PAH). Unlike some ED medicines, tadalafil can work for up to 36 hours — that’s why people call it the “weekend pill.”

It works by relaxing blood vessels so blood flows more easily to the penis and other tissues. That means it helps you get and keep an erection when you’re sexually aroused. For BPH, it eases urinary symptoms by relaxing smooth muscle in the prostate and bladder.

Quick dosing guide

Here are common dosing patterns you’ll see. Always follow your doctor’s prescription.

• ED, as-needed: 10 mg taken at least 30 minutes before sex; dose may be adjusted to 5 mg or 20 mg.
• ED, daily: 2.5–5 mg once daily if you prefer spontaneous activity.
• BPH: 5 mg once daily.
• PAH: higher, specialized doses under a specialist’s care (do not self-adjust).

Onset varies. Many feel effects in 30–60 minutes, but food and alcohol can slow it. The long duration is useful, but it doesn’t cause an erection without sexual stimulation.

Safety tips and red flags

Common side effects include headache, flushing, indigestion, back pain, and muscle aches. These often fade in a day or two. Serious problems are rare but important to know:

• Never take tadalafil with nitrates (nitroglycerin, isosorbide). That combo can cause a dangerous drop in blood pressure.
• If you use alpha-blockers for prostate or blood pressure, start low and use medical guidance to avoid fainting.
• A sudden loss of vision or hearing, or an erection lasting more than four hours (priapism), needs emergency care.
• Tell your doctor about heart disease, low blood pressure, liver or kidney issues before starting tadalafil.

Tadalafil is processed by the liver enzyme CYP3A4. Strong inhibitors (like ketoconazole) raise tadalafil levels; inducers (like rifampin) lower them. Avoid large amounts of grapefruit juice.

Thinking of buying tadalafil online? Use a licensed pharmacy that requires a prescription, shows a physical address, and offers pharmacist contact. Avoid sites that sell without a prescription or use suspicious domain names. Our site has reviews and guides to help you spot safe pharmacies and avoid scams.

Want alternatives? Sildenafil is the most common alternative and works faster but for a shorter time. Daily low-dose tadalafil can suit men who prefer spontaneity. Talk with your clinician about what fits your health, heart risk, and lifestyle.

If you have questions about a specific dose, side effect, or how tadalafil mixes with other meds, ask your prescriber or pharmacist. They’ll tailor advice to you — and that’s the safest route.