It lasts 4 to 5 hours, or longer if you have mild to moderate ED. Medicines that you take by mouth are called oral medicines. Often, these are prescribed for chest pain called angina. 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 experience chest pain, dizziness, or nausea during sex, seek immediate medical help. It might work longer if you have mild to moderate erectile dysfunction. They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar.Best subscription service for Viagra and generic Viagra: Rex MD Viagra Although erectile dysfunction (ED) may be an upsetting diagnosis for some, many people . MORE expand_more Check your prescription Prescription mg sildenafil (30 tablets) edit Choose your pharmacy moses lake, WA Safeway Walgreens Rite Aid info How to . Sildenafil (Viagra) may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or .