Well, It’s all depending on your dose you take, your body’s metabolism and many other external factors which treat ED (erectile dysfunction) Erectile dysfunction is a common condition that can affect males of any age and treat certain heart conditions. Sildenafil is a very common medication used to stimulate erections in men with ED. Sildenafil It’s the most commonly known medication as Viagra.

Viagra mostly starts working in 30–60 minutes after you take it in oral tablet form. Well, it may take up to two hours to work. Viagra is not a magic pill that works on its own. You have to feel sexually aroused to get an erection. Feeling comfortable and relaxed can also help Viagra take effect sooner.

Viagra can last up to 4 to 5 hours or longer depending on how your body metabolizes it, you may be able to get an erection a bunch of times with Viagra in your body. It’s probably won’t make you last longer in bed, though. No research has proven that Viagra can increase how long you can have sex.

These Viagra tablets typically come in 25, 50, or 100 milligrams (mg) dose. One of the older studies shows that the risk of side effects does not increase when going from 50 to 100 mg doses of Viagra. However, taking a much higher dose will increase effectiveness.

The effects of Viagra are different for each individual. The effects of taking 100 mg Viagra can last for up to 4 to 5 hours after taking the drug. But the strength of these effects is weaker at 4 hours than 2 hours after taking Viagra.

Several other important factors can also influence how long Viagra lasts for you:

Age. As you get much older, your metabolism slows down. Thus, Viagra medicine may last longer as you age. In general, you may see Viagra works for a longer period of time when you’re 65 or older.

Diet. Eating a rich meal or a lot of high-fat foods right before you take Viagra can keep it from being metabolized quickly or effectively. But this can also make viagra last longer in your body as it’s metabolized along with your meal. Drinking alcohol can also reduce blood flow to your penis, making Viagra less effective or shorter-lasting.

Dosage. The amount of Viagra you take affects how long it stays in your body system. The smallest viagra medicine available in 25-milligram (mg) dose won’t last as long as the largest available 100-mg dose. But taking a high dose of Viagra isn’t always recommended, as it may not be safe for you.

Medications. Some medications, especially antibiotics such as clarithromycin (Biaxin), ciprofloxacin (Cipro), and erythromycin (Ery-Tab), can interact with Viagra and affect how long it lasts.

Overall health. Some conditions can affect how long Viagra lasts and how well it works for you. Some conditions are nervous system conditions like multiple sclerosis and heart conditions like atherosclerosis and diabetes can all make Viagra less effective and not last as long Some kidney conditions may make Viagra last longer because of the condition’s its effect on your metabolism.

Psychological state. Feeling anxious, depressed, nervous, or stressed can all affect your body responds to sexual stimulation. If you’re not comfortable with your partner during sex or if you have any performance anxiety because of past sexual experiences, Viagra may not last long or be fully effective.

How long Viagra stays in your body system :

• Viagra reaches the maximum level in your body system around 1 hour after you take it
• After 8 hours there is only around 10% of the amount of the maximum level of Viagra left in your body system.
• After 24 hours all the Viagra in gone from your body system and you can take another dose of Viagra again

A higher dosage of Viagra will take longer to leave your body. A 25-mg dose may wear off after a couple of hours, but the 100-mg dose of Viagra may take nearly four times as long to leave your system.

Some medicines for heart conditions, such as nitroglycerin and other nitrates, can interact dangerously with Viagra and cause your blood pressure to drop.

Talk to your doctor before you take any Viagra or any related medication for ED. it’s very important to take a safe dose and work out a clear understanding of how much you should take in a 24-hour period.

If Viagra is not working or isn’t safe for you, talk to your doctor about other possible treatments for ED