Check with your doctor right away if you have a sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears. If you have erection problems sildenafil works by temporarily increasing blood flow to your penis when you get sexually excited. This medication is taken with or without food an hour before sex. Viagra is also available in doses of 25mg and mg, so your prescriber will be able to advise whether a lower or higher dose might suit you better. Or you can visit mayoclinic. May make this condition worse. When side effects do occur , these are generally mild and short-lived.1 day ago · How much does Viagra cost online? What dosage is available? Hims: yes: yes – starting at $ per dose of Viagra – starting at $4 per dose of sildenafil, depending on dosage: 25– mg. The Savings Offer and Program expire on 12/31/ For further information, call , visit , or write: Viatris Inc., P.O. Box , Mission, KS Eligible patients may save on their VIAGRA® (sildenafil citrate) prescription with the VIAGRA savings card. Key facts. Sildenafil (Viagra) is a medicine used to treat erectile dysfunction (ED, also called impotence). Sildenafil works by helping to relax the blood vessels in the penis, allowing more blood to flow in and cause an erection. You should take sildenafil about an hour before planned sexual activity, so it has time to work.