Medically Reviewed by HaVy Ngo, Pharm.D.

Last Reviewed: Jun 01, 2022

Side Effects


What are Viagra (sildenafil) side effects?

Get emergency help immediately if you experience hives, shortness of breath, swelling of your face, lips, tongue, and throat—These are signs of an allergic reaction to sildenafil (Viagra). 

The most common side effects of Viagra include:

  • Headache
  • Flushing
  • Nasal congestion
  • Indigestion
  • Light sensitivity or blurred vision
  • Back pain or muscle aches
  • Dizziness
  • Nausea
  • Rash
  • Insomnia (sleep problems)


These Viagra side effects do not usually require medical attention and often get better over time as the body gets used to the drug. However, you should report these side effects of Viagra to your prescribing physician if they do not improve or are bothersome.

There can be more serious side effects of Viagra. Stop taking Viagra and get emergency medical care if you experience these symptoms:Allergic reactions as mentioned above 

  • Heart attack symptoms: burning feeling in the chest or stomach, radiating pain to your jaw or shoulder, sweating, nausea
  • An erection lasting more than 4 hours, with or without pain and discomfort (priapism)
  • Vision loss or vision change with unknown cause


Let your doctor know if you have the following symptoms:

  • Hearing loss or ear ringing
  • Bladder pain, pain on urination, increased frequency of urination, bloody or cloudy urine
  • Burning, itching, crawling, numbness, or pins and needles sensations
  • Upset stomach


The above list may not include all the potential side effects of Viagra (sildenafil). Speak to your doctor if you have severe side effects or if the side effects do not improve over time. You can also report unusual Viagra side effects to the Food and Drug Administration at 1-800-FDA-1088.

Viagra Overdose: If you think you have taken too much Viagra, call your doctor or call the Poison Help Line at 1-800-222-1222. If your symptoms are severe, please call 911 and seek emergency medical care immediately. 

Symptoms of an overdose of Viagra include:

  • Dangerously low blood pressures
  • Chest pain
  • Dizziness
  • Fainting
  • Nausea
  • Vision problems
  • Hearing problems  


NOTE: Viagra is a prescription medicine to be used only by you—never share your Viagra with others or use someone else’s Viagra tablets.

Source: FDA