These medicines all work well for ED. However, eating food, particularly high-fat food, can reduce the effectiveness of Viagra. Often, these are prescribed for chest pain called angina. It works best when taken one hour before sex. Viagra can be taken as long as four hours or as little as 30 minutes before sex. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow.AdDon’t go to the pharmacy without checking prices at GoodRx® first. No commitment or fees. Find the lowest price in your neighborhood & use our free coupons to save up to 80%No Credit Card Required · 5-Star Reviews · Over 70k Pharmacies · No Insurance RequiredRanked at No. 20 on the Disruptor 50 list. – CNBC. Viagra dosage for erectile dysfunction (ED) is usually milligrams (mg), but those over 65 may start at 25 mg. Your doctor will also need to consider possible drug interactions. MNT ‘s review. Lemonaid sells Cialis in these forms: Cialis: available in doses of 5, 10, and 20 mg, starting at $65 per tablet. Daily Cialis: 5 mg tablet with pricing starting from $50 per tablet.