Tadagra Prof 20 mg is commonly marketed as containing tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED) in adult men. Since brand formulations can vary between manufacturers and countries, check the product packaging to confirm the active ingredient and strength. Tadalafil works by increasing blood flow to the penis when sexual stimulation occurs, helping achieve and maintain an erection. It does not directly increase sexual desire, testosterone, or sexual arousal. A 20 mg tadalafil dose is generally used as needed for ED rather than as a daily treatment. Tadalafil has a relatively long duration of action, which can provide flexibility around the timing of sexual activity.