Viagra: Uses, Dosage, Side Effects, Warnings - Drugs.com Sildenafil citrate is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7. VIAGRA is formulated as blue, film-coated rounded-diamond-shaped tablets equivalent to 25 mg, 50 mg, and 100 mg of sildenafil for oral administration. Viagra is used in adult males to treat ED. The active ingredient...