However, some states require a live video consultation. The information provided here is based on credible sources and reputable medical references. RexMD understands that healthcare is not a one-size-fits-all concept and offers personalized treatment plans for all of its patients. We also looked at additional services, such as access to digital pharmacies and home delivery options. Other warning signs of an unsafe online pharmacy include outdated medication, no customer service, or suspiciously low prices.Cialis and generic tadalafil are available in four different strengths— mg, 5 mg, 10 mg and 20 mg—but which one should you take? If you’ve never tried Cialis before, your doctor will likely start you on a low dose, like mg or 5 mg. The 20 mg tablet is the highest strength and is often not preferred because it has the potential to. Uses. Tadalafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, tadalafil works by increasing blood flow to the penis. The most common side effects with Cialis are: headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. These side effects usually go away after a few hours. Men who get back pain and muscle aches usually get it 12 to 24 hours after taking Cialis. Back pain and muscle aches usually go away within 2 days.