An erection results from an increase in blood flow to the penis. Patients should always ask their doctors for medical advice about adverse events. It’s available in 10 mg and 20 mg tablets. It’s best to check your chosen provider’s site for more information. Online pharmacies also may not fill short-term prescriptions, such as those for antibiotics. Most erectile dysfunction medications belong to the drug class known as PDE5 inhibitors , which help relax the muscles and increase blood flow to allow for a full erection.Dizziness, headache, flushing, or stomach upset may occur. Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green colors apart may also occur. If.  · The most promising supplement for boosting testosterone, according to Dr. Desai, is ashwagandha. A study in the American Journal of Men’s Health examined overweight men, ages 40 to 70, with.  · Is Viagra prescribed in dosages of mg, mg, or mg? The highest recommended Viagra dose for treating erectile dysfunction (ED) is mg per day, according to the drug’s manufacturer.