What You Should Know About Viagra

Viagra (sildenafil) is an oral medication that treats erectile malfunction in men. It works by blocking some naturally occurring enzymes, which cause blood vessels to dilate. This improves blood flow to the penis.

It takes about an hour to take effect — but it only helps with an erection if you’re sexually aroused and stimulated. It also needs to be taken on an empty stomach, as a fatty meal can delay the drug’s absorption.


There are many medications used to treat erectile dysfunction (ED), but Viagra is unique among them because it works only when you’re sexually aroused. The medication increases blood flow in the corpora cavernosa, which helps to increase the muscle movements required to create and maintain an erection.

It begins to work about an hour after taking the tablet. However, it can take longer or less time depending on what you eat. You typically only take Viagra once a day, and it works best when taken about an hour before sex.

Most likely, your doctor will start you out on 25mg Viagra. This is the lowest dosage that most people can tolerate. It’s also the lowest dosage that’s been proven to be effective in clinical trials. The lower dose may help reduce the risk of side effects, such as visual disturbances and a blue haze. You can also choose this option if you suffer from health conditions or are taking drugs that interact negatively with Viagra.

Side effects

Besides helping men get and keep an erection, Viagra also helps blood vessels around the body to relax. This can help heart conditions such as angina pectoris. Angina pectoris is a type chest pain caused by cardiovascular issues.

In some cases, Viagra can cause mild side effects such as headache or a runny or blocked nose. You may also feel dizzy or lightheaded. If this happens, you can either lie down or remain seated until your symptoms improve.

Viagra may not be safe for you if you have certain health problems, such as blood cell disorders (such as sickle cell anemia or multiple myeloma), or a history of Peyronie’s disease. It can be dangerous if your nitrate medication, such as nitroglycerin, is prescribed for chest pain or high pressure. The pill’s effectiveness can be affected by consuming a fatty food, and alcohol can reduce the duration of the effect. Speak to your doctor about this medication.


Viagra can cause a sudden fall in blood pressure, which can make you feel nauseous or dizzy. This is more likely to happen if you combine Viagra with certain drugs that treat high blood pressure, enlarged prostate or alcohol. Talk to your doctor if you have these conditions before taking Viagra.

You should also avoid drinking a lot of alcohol while taking Viagra. Some side effects, such as flushing and headaches, can be made worse by alcohol.

You should not take Viagra if you have a heart condition or a history of stroke, or if you are taking nitrate drugs (such as nitroglycerin or isosorbide dinitrate/mononitrate, used to treat chest pain). Nitrates may block Viagra’s action. This medication can also cause a long-lasting and painful erection, called priapism. Priapism can damage your penis and lead to permanent ED.

Other Drugs

If a person takes Viagra for a long period of time, it may affect their ability to induce an erection naturally. This can lead to a psychological dependence on Viagra, and a desire for it to be taken even when there isn’t a sexual need. This can also lead to relational problems and distress.

Viagra should not be taken by people who have certain eye conditions such as non-arteritic anterior ischemic optic neuropathy (NAION) or hereditary retinitis pigmentosa because it can cause sudden loss of vision in one or both eyes. It should be used with caution by people who have low pressure, as it can cause blood pressure to drop to unsafe levels.

Other medications such as over-the-counter ibuprofen, alpha-blocker drugs such as Terazosin or doxazosin (used for high blood pressure treatment and benign prostatic hyperplasia), and alpha blocker medication like terazosin and the doxazosin can interact with Viagra. These interactions can decrease the effectiveness of the drug or cause side effects.