Kamagra 100, which contains sildenafil citrate, usually starts acting within 30 to 60 minutes of intake. For the best benefits, take it on an empty stomach, since heavy or fatty meals may cause it to take longer to kick in. The medicine works by boosting blood flow to the penis, allowing men to attain and sustain an erection when sexually stimulated. 

Its effects can last up to 4 to 6 hours, though this varies depending on the individual. How soon it works is influenced by factors like as age, metabolism, and overall health. Always adhere to medical recommendations to ensure safe and effective use.