100mg of a blue sildenafil pill.

Published On November 25, 2019

What Happens If You Take Too Much Sildenafil?

Sildenafil, sold under the brand name Viagra, is used to treat erectile dysfunction (impotence) in men. First approved by the FDA in the United States in 1998, it has gone on to become one of the most prescribed medications worldwide. It belongs to a class of drugs called PDE5 inhibitors that work by relaxing the muscles in the penis and increasing blood flow to the organ to make it erect. Sildenafil is effective, and for the most part, a safe treatment for erectile dysfunction. But like all medications, it is associated with some side effects. These adverse effects are usually temporary and mild. However, taking too much sildenafil or taking it with certain other medications can cause potentially dangerous complications.

What is the Correct Dose of Sildenafil?

In men with erectile dysfunction, sildenafil is usually prescribed at a dose of 25 mg, 50 mg, or 100 mg orally once a day, to be taken anywhere between half an hour to 4 hours before sexual activity (typically 1 hour before).1 In most men, the recommended dose is 50 mg. The maximum recommended frequency of use is once per day.2

The geriatric dose for older men with ED is 25 mg.1 A lower dose may also be prescribed for men with severe renal dysfunction or hepatic impairment. The medication has not been tested for safety and efficacy in patients less than 18 years old.1

It is worth noting that Viagra does not work without sexual stimulation. Simply taking the pill will not give a man an erection. The medication can be taken with or without food; however, if it is taken shortly after a high-fat meal, it may take longer to work.2 These factors are important because some men with erectile dysfunction take an extra dose of sildenafil when they obtain no response after using the drug incorrectly.

What are the Side Effects of Sildenafil?

The most common adverse effects are headache, dyspepsia, stuffy or runny nose, flushing, rash, vision changes, dizziness, and muscle pain.2 In most men, these side effects of sildenafil are mild and decline with continued use. However, if they are bothersome or persistent, the prescribing doctor can adjust the dose or switch to another treatment for erectile dysfunction.

Rarely, sildenafil can cause more serious medical complications such as priapism (a prolonged and painful erection that won’t go away), sudden vision loss in one or both eyes, and decreased hearing, ringing in the ears (tinnitus), or hearing loss. These symptoms require immediate medical attention. Use of the medicine should be stopped immediately and the prescribing doctor should be contacted.2

It is also important to know that sildenafil has drug interactions with certain other medications, including nitrates used for the treatment of chest pain, riociguat for pulmonary hypertension, and alpha-blockers for high blood pressure or prostate problems. Taking these medications together with sildenafil can result in a sudden and dangerous drop in blood pressure.2 That’s why it’s important to tell the doctor about all the medications you’re on before starting treatment for erectile dysfunction.

What Happens if You Take Too Much Sildenafil?

An overdose of sildenafil can be either intentional or inadvertent. It may consist of exceeding the recommended maximum dose of 100 mg or taking the medication more than once a day.

If you take too much sildenafil, the chances of side effects occurring is higher.3 Men who use this ED drug more than once a day report increased muscle aches and dyspepsia.4 There is also an increase in visual side effects, headaches, and flushing.4 A total daily dose of more than 100 mg is associated with a higher incidence of cardiovascular events such as tachycardia and hypotension (low blood pressure).4 Combining sildenafil with other medicines for erectile dysfunction (PDE5 inhibitors such as tadalafil, vardenafil, or avanafil) also increases the risk of adverse effects.3 Importantly, sildenafil overdose is associated with a two times higher risk of priapism (prolonged erection). This is a medical emergency and can result in erectile dysfunction because of permanent damage to the penile tissues.4

In general, sildenafil has low toxicity and a significantly high safety margin. It does not cause problems with reproduction. It is not a known carcinogen (cancer-causing agent). Nonetheless, every man reacts to the erectile dysfunction treatment differently. There are reports of ultra-high doses of sildenafil up to 1300 mg taken at a frequency of 2-3 times a week for several years resulting in nothing more than a transient blurring of vision.5 On the other hand, a single sildenafil overdose has been known to result in permanent visual disturbance and damage to the eyes.6

Safe Use of Sildenafil

The maximum approved dose of sildenafil for erectile dysfunction is 100 mg once per day. When used at the correct dose, this ED drug is safe with less than 5 percent of men reporting side effects that require changes in dose or discontinuation of treatment.7 Studies have shown that more than 90 percent of men are satisfied with sildenafil treatment and the quality of their erections.7 To ensure the safe use of this medication, always consult a physician, obtain a prescription, and take sildenafil for erectile dysfunction at the recommended dose and frequency.


  • https://www.drugs.com/dosage/sildenafil.html
  • https://www.viagra.com/taking/finding-the-right-dose
  • https://www.mayoclinic.org/drugs-supplements/sildenafil-oral-route/precautions/drg-20066989
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810448/
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4623654/
  • https://www.forbes.com/sites/brucelee/2018/10/04/what-may-happen-if-you-take-too-much-erectile-dysfunction-medication/#226101c724c5
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2387281/