Knowing the background information of any drug you’re currently taking is critical. But when taking medicines on an “as needed” basis, understanding how long their effects can last and how long it stays in your system is of paramount importance.
What are “as needed” medications? These are drugs you take whenever you need them, rather than taking them daily with a meal.
For medicines belonging to the category of erectile dysfunction (ED) drugs known as PDE5 inhibitors like sildenafil (Viagra®), you would generally need to schedule your doses within certain times before engaging in sexual activity.
If you take your sildenafil dosage too early before the festivities between the sheets begin, it might have already exited your system to experience its maximum effect.
On the other hand, taking your sildenafil dosage too close to the romance might mean it may not have enough time to be adequately metabolized by your body for its effects to kick in.
In other words, timing is everything when it comes to sildenafil and its fellow PDE5 inhibitor ED drugs like tadalafil (Cialis®), vardenafil (Levitra®), and avanafil (Stendra®).
Let’s go on a deep dive on how long sildenafil stays in your system, how it works, and how long its effects last in the body.
How does sildenafil (Viagra®) work?
Sildenafil acts as a PDE5 inhibitor, a category given to drugs that treat ED by boosting blood flow to the penis and producing longer-lasting or firmer erections for men with the condition.
Erections are typically produced after sexual stimulation, physical touch, or erotic implements. Whenever this happens, such stimulation reaches the pelvic nerves, releasing nitric oxide (NO), a neurotransmitter responsible for sildenafil’s relaxing effect on the penile muscles.
Nitric oxide is transported through the penile arteries and blood vessels, allowing blood to flow freely to the penile tissue and the smooth muscles responsible for producing erections.
NO also increases cyclic guanosine monophosphate (cGMP), which relaxes penile smooth muscles that lead to an erection.
However, just inside the cavernous smooth muscles is phosphodiesterase type-5 (PDE5). This enzyme limits blood flow and causes the smooth muscles and penile blood vessels to contract, signaling the body to terminate and diminish the erection process.
Sildenafil and its ilk work to prevent PDE5 from diminishing cGMP levels by binding the former, allowing cGMP to build up and increase its concentrations. This effect may lead to an increase in healthier erections.
Getting ED medication has never been easier
Connect with a US-licensed healthcare provider for a FREE evaluation!
Free Express
Shipping
Discreet
Shipping
No Waiting
Rooms
How long does sildenafil stay in your system?
The half-life of a drug refers to the time it takes for the body to expel 50% of its active ingredient. Drugs are eliminated from the system through excretion via urine and metabolism, in which the liver processes the drug into another molecule for excretion via urine.
Oral sildenafil doses between 25 and 200 mg last in the system for approximately three to four hours.
This means that after approximately four hours, only half of the sildenafil will have remained in your system compared to when its full effects peak.
This doesn’t mean that its effects will instantly wear off because half of the active ingredient is gone – sildenafil may still work for a couple more hours after this time.
Drugs are largely cleared from the body after five half-life periods or cycles. In sildenafil’s case, that means somewhere along the lines of 16-20 hours after taking your dose. After the said time frame, the medication will have almost fully exited your system.
Check out the following breakdown of how much sildenafil remains based on its half-life:
- After one half-life cycle (3-4 hours); 50% of peak sildenafil content remains
- After two half-life cycles (6-8 hours): 25% of peak sildenafil content
- After three half-life cycles (9-12 hours): 12.5% of peak sildenafil content
- After four half-life cycles (12-16 hours): 6.25% of peak sildenafil content
- After five half-life cycles (15-20 hours): 3.125% of peak sildenafil content remains
After five half-life cycles, only a minuscule amount of peak sildenafil concentrations should still be in your system.
However, as there may still be some residual sildenafil in the bloodstream after 24 hours, it is advisable to avoid taking drugs that may interact or add to its effects in that time frame after your last dose. This also means not taking more than one dose of any erectile dysfunction drug daily.
Getting ED medication has never been easier
Connect with a US-licensed healthcare provider for a FREE evaluation!
Free Express
Shipping
Discreet
Shipping
No Waiting
Rooms
How long does sildenafil produce effects in your system?
As we’ve just seen, a residual amount of sildenafil remains in your body approximately 24 hours after taking your first dose.
On the other hand, the question of how long sildenafil’s effects remain functioning in the body is another hill of beans.
Most sildenafil users, on average doses, will likely feel suitable effects from sildenafil to treat their ED symptoms up to 3-4 hours, or the first half-life of the drug.
After this first half-life, there will still be sildenafil in your system, but not at sufficient concentrations to produce the same effects as the first 3-4 hours do.
If you feel that this approximately 4-hour time frame doesn’t suit you and your partner’s sexual needs, ask your doctor about going on a different ED drug with a longer half-life known as tadalafil (Cialis®), which may help you enjoy more spontaneity in sexual activity.
An important reminder about the mechanism of action of sildenafil
Whenever we talk about the window of activity of sildenafil or other ED drugs of its class, it’s important to remember that the time frames reported represent the window in which the drug makes it easier for the body to produce an erection, not the time frame it should keep your erections hard.
If you experience an erection lasting three to four hours or longer, seek immediate medical attention. This condition is called priapism and is a rare, painful side effect of taking sildenafil that may cause permanent damage to the penis if left unattended.
