Sildenafil (Viagra)

Sildenafil is a prescription medication used to treat erectile dysfunction (ED). It is the generic name for the well-known brand Viagra and belongs to a class of drugs called PDE5 inhibitors.

Sildenafil is also used under another brand name (Revatio) to treat pulmonary arterial hypertension (high blood pressure in the lungs).

Sildenafil works by increasing blood flow to the penis. It relaxes blood vessels by enhancing the effects of a natural chemical called nitric oxide.

This relaxation allows more blood to enter the penis when you are sexually aroused, resulting in a firmer, longer-lasting erection.

No. This is a very common misconception. Sildenafil only works when you are sexually stimulated or aroused.

It does not increase your libido (sex drive) and will not create an erection on its own without sexual stimulation.

• When to take it: Take your prescribed dose about 30–60 minutes before you plan to have sex. It can be taken up to 4 hours before sexual activity.
• With or without food: Sildenafil works fastest on an empty stomach. A high-fat meal can delay its effect.
• Dosage: Do not take more than one dose in a 24-hour period unless specifically instructed by your provider.

The effects of Sildenafil typically last for about 4–6 hours.

During this window, you should be able to achieve an erection more easily when you are aroused. The duration is generally not affected by the dosage.

Most side effects are mild and temporary. The most common include:

• Headache
• Facial flushing (warmth and redness)
• Upset stomach or indigestion
• Stuffy or runny nose
• Dizziness
• Changes in vision (such as a blue tinge or blurred vision)

You must review your full medical history with a licensed provider before starting Sildenafil. Important safety points include:

• Do NOT take Sildenafil if you take nitrates. Nitrates (like nitroglycerin) are used for chest pain (angina). Combining them with Sildenafil can cause a sudden, dangerous drop in blood pressure.
• Seek emergency help if you have an erection that is painful or lasts longer than 4 hours (priapism), as this can cause permanent damage.
• Stop taking Sildenafil and see a doctor right away if you experience sudden vision loss, hearing loss, or chest pain during or after sex.
• Use with caution if you have a history of heart problems, stroke, low blood pressure, liver or kidney disease, stomach ulcers, or certain eye conditions.

Both Sildenafil and Tadalafil are PDE5 inhibitors used to treat ED, but they differ in how long they last and how they are typically used.

• Sildenafil (Viagra): Lasts about 4–6 hours and is taken “on demand.”
• Tadalafil (Cialis): Can last up to 36 hours, earning it the nickname “the weekend pill.” It also comes in a low-dose daily option.

Light alcohol use is generally allowed, but heavy drinking can make it harder to get an erection and may counteract the benefits of the medication.

Alcohol can also increase the risk of side effects like dizziness, headache, and low blood pressure.

Sildenafil is a prescription medication intended to treat the medical condition of ED. Using it without a medical need or prescription is not recommended.

Some experts warn this can lead to psychological dependence, where you may start to feel you cannot get an erection without the pill even if you are physically healthy.

Sildenafil (Viagra) is not approved to treat sexual dysfunction in women, and there is no strong evidence that it is effective for this purpose.

A different brand of sildenafil (Revatio) is used to treat pulmonary hypertension in both men and women, but this is a distinct medical indication and dosing regimen.

This FAQ is for informational purposes only and does not constitute medical advice. Always consult with a licensed healthcare provider to determine whether Sildenafil is appropriate and safe for you.