Tadagra 20 mg is a medication used to treat erectile dysfunction (ED) in men. It contains tadalafil as its active ingredient, which is a phosphodiesterase type 5 (PDE5) inhibitor. Like all medications, Tadagra 20 mg may cause side effects. Common side effects may include headache, back pain, muscle aches, indigestion, and flushing. It is essential to report any unusual or severe side effects to your healthcare provider.