OverviewDosageSide EffectsInteractionsHalf-Life

Sildenafil is currently the 217th most commonly prescribed drug in the United States. In 2017 alone, there were over 2.3 million prescriptions written. Considering how popular this drug is right now, it pays to know a little bit more about this medication, including how long sildenafil stays in your system.

The U.S. Food and Drug Administration (FDA) states the following information regarding sildenafil half-life:

Mean effective half-life: 4 hours

Time to steady-state: 30 to 120 minutes (60 minutes on average)

Mean accumulation ratio: 1.58 (whole blood) to 1.64 (plasma)

Terminal phase half-life: 4 hours

Sildenafil has an oral bioavailability of about 41%. It is rapidly absorbed after ingestion. Once metabolized, sildenafil is primarily excreted by the feces; a smaller amount is excreted through the urine.


How long does sildenafil stay in your system?

Sildenafil has a half-life of 4 hours, which is how long it takes for the body to clear half of this substance. This fact does not mean an erection will last that long, though. Anyone taking sildenafil who experiences an erection lasting longer than 4 hours should seek medical attention immediately, even if it’s not painful.

Plasma, serum, or even whole blood tests, experts say, might detect Viagra’s metabolite, N-desmethyl sildenafil, a few hours after the last dose. However, it is unlikely that someone would be screened for the presence of this drug.

What is the best time to take sildenafil?

The U.S. National Library of Medicine recommends that the best time to take sildenafil for erectile dysfunction is about one hour prior to sexual activity. Anywhere from 30 minutes to 4 hours prior to sex is within an appropriate range; however, sildenafil (as Viagra) should not be taken more than once per day. When taking sildenafil (as Revatio), the dosage is lower and is prescribed three times per day.

Doctors often advise their patients to take sildenafil on an empty stomach for maximum effect. But, it can be taken with food, too. 

What is the peak time for Viagra?

Viagra starts working at its peak effect anywhere from 30 to 120 minutes after it’s ingested (around 60 minutes on average).

How long does sildenafil 25mg last?

Sildenafil 25mg is a lower dose and may last up to a couple of hours. 

How long does sildenafil 50mg last?

Sildenafil 50mg typically lasts four to six hours in the body. Higher doses of up to 100mg are available. 

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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