This can cause anxiety, which might make erectile dysfunction worse. Join now! In some cases, online ED providers accept health insurance. When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. It’s available in 50 mg, mg, and mg tablets.Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision . Viagra takes around 30 minutes to become effective and lasts about 4 hours. Cialis lasts much longer — up to 36 hours in some cases. Stendra can start doing its thing in as little . A sildenafil (generic Viagra) membership starts at $20 monthly for six tablets of 30 mg. For $ each month, you’ll receive 34 sildenafil tablets of 45 mg each. Generic Viagra .