Kamagra Oral Jelly Vol 1 contains sildenafil citrate, a PDE5 inhibitor used to manage erectile dysfunction in eligible adult men. It works by improving blood flow to the penis during sexual stimulation, helping achieve and maintain an erection. Possible side effects include headache, flushing, indigestion, dizziness, and nasal congestion. It should not be used with nitrate medicines because the combination can cause a dangerous drop in blood pressure. Consult a qualified healthcare professional before use, especially if you have heart problems or take other medications.