Viagra is a well-known prescription medication used to treat erectile dysfunction (ED), a condition where a man is unable to achieve or maintain an erection sufficient for sexual activity. The active ingredient in Viagra is sildenafil, which works by increasing blood flow to the penis, helping men achieve and maintain an erection when sexually aroused.

Key Featurces of Viagra:

Active Ingredient: Sildenafil:

Sildenafil is a PDE5 inhibitor that works by blocking the enzyme phosphodiesterase type 5 (PDE5). PDE5 is responsible for the breakdown of cGMP, a compound that helps relax the blood vessels in the penis and allows increased blood flow during sexual arousal. By inhibiting PDE5, sildenafil helps to maintain higher levels of cGMP, which leads to an erection.

Primary Use:

Erectile Dysfunction (ED): Viagra is primarily prescribed for men with erectile dysfunction, which may be caused by a variety of factors including age, stress, medical conditions (like diabetes, hypertension), or lifestyle factors.
Pulmonary Arterial Hypertension (PAH): Sildenafil (under the brand name Revatio) is also used to treat pulmonary arterial hypertension, a condition involving high blood pressure in the lungs, although this is not the primary use for Viagra.

How Viagra Works:

Viagra works by increasing blood flow to the penis when a man is sexually stimulated. It does not cause an erection on its own; sexual arousal is still required to trigger the mechanism.
It typically starts to work 30 minutes to an hour after taking the pill, and its effects can last for 4-5 hours.

Dosage:

Standard Dose: The typical starting dose of Viagra is 50 mg, but it can be adjusted depending on individual needs and tolerance. It can be increased up to 100 mg or reduced to 25 mg.
Administration: Viagra is usually taken as a single oral dose about 30 minutes to 1 hour before sexual activity. It should be taken on an empty stomach for the best effect, as high-fat meals can delay the onset of action.

Effectivenecss:

Viagra is generally effective for most men with ED, helping them to achieve and maintain an erection when sexually aroused. It is often referred to as one of the most well-known and reliable treatments for ED.
The onset of action typically occurs within 30 minutes, and its effects last for about 4-5 hours. This provides a window of opportunity for sexual activity, though it does not guarantee an erection without sexual stimulation.