Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine. The company has five FDA -approved ED medications tested extensively and considered safe and effective for most men. Are there any natural remedies for ED? It is important to explore these options and discuss them with healthcare professionals to find the most affordable solutions. It is optional to have any further orders written. Some medications should not be taken with sildenafil.An FDA investigation found that more than one-third of “dietary supplements” sold for ED actually contained prescription drugs, including sildenafil, the medicine in Viagra. Some .  · VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or mg of sildenafil. Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR on the other to indicate the dosage strengths. 4. Contraindications. Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP.