It usually takes 30 to 60 minutes for tadalafil to take its effect on erectile dysfunction. You can take 1 tablet once a day, at least 30 minutes before you want to have sex. Taking tadalafil on its own is not enough to cause an erection. You need to be sexually aroused for it to work.
For benign prostate enlargement:
Tadalafil tablets for an enlarged prostate come as smaller doses: 2.5mg or 5mg. The usual dose is 5mg, taken once a day. You can take your tablet in the morning or evening, but it’s best to take it at the same time each day.
Your doctor might give you a low dose of 2.5mg if you are having any problems, such as side effects.
If you are being treated for both benign prostatic enlargement and erectile dysfunction, the dose is 5mg.