Extra 15% off $30 sitewide with code SAVE15; Clip your mystery deal! BOGO 50% off select Walgreens health & wellness.If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men. The most common side effects of VIAGRA: headache; flushing; upset stomach; abnormal vision, such as changes in color vision such as having a blue color tinge and blurred vision; stuffy or runny nose; back pain; muscle pain; nausea; dizziness; rash. If you do not have a plastic syringe or spoon, ask your pharmacist for one. Do not stop taking sildenafil without talking to your doctor. This medicine is available on prescription and you can also buy it from most pharmacies. Before taking sildenafil, tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil tablet or suspension.Cialis is only available by prescription in the United States. Viagra: Additionally, a study from Trusted Source. found that combining L-arginine and sildenafil (Viagra) worked better for. 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. This medicine is available on prescription and you can also buy it from most pharmacies. It comes as standard tablets, chewable tablets, and as a liquid that you swallow. Key facts. It usually takes 30 to 60 minutes for sildenafil to work for erectile dysfunction. You can take it up to 4 hours before you want to have sex.What special precautions should I follow? About sildenafil Viagra Sildenafil is a medicine used to treat erection problems erectile dysfunction. Box , Mission, KS If your pharmacy does not participate, you may be able to submit a request for a rebate in connection with this Savings Offer. If you have erection problems sildenafil works by temporarily increasing blood flow to your penis when you get sexually excited. Tell your doctor or pharmacist if you are taking nitrates medications for chest pain such as isosorbide dinitrate Isordil , isosorbide mononitrate Monoket , and nitroglycerin Nitromist, Nitro-Dur, Nitrostat. Your doctor will tell you not to take sildenafil if you are taking street drugs containing nitrates. Do not stop taking sildenafil without talking to your doctor.