Sildigra 100 mg belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. It works by inhibiting the enzyme PDE5, which helps relax blood vessels in the penis. This action allows for increased blood flow and better erections. Common side effects of Sildigra 100 mg may include headache, flushing, indigestion, nasal congestion, dizziness, and vision changes. These side effects are usually mild and temporary. If you experience any severe or persistent side effects, seek medical attention.