The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment. A healthcare provider can help. Viagra is the brand name of sildenafil, an oral medication that is taken to treat erectile dysfunction ED. Viagra works by blocking cGMP-specific phosphodiesterase type-5 PDE-5 , an enzyme that ends an erection by making blood flow out of the penis.
It relaxes smooth muscle and encourages blood vessels to widen a process known as vasodilation. That makes blood flow more freely, including to the penis. A real, U. You must be sexually aroused for it to work. Brand name Viagra comes in three dosages: 25 mg, 50 mg, and mg. Sildenafil can also be prescribed off-label as the generic form of a drug called Revatio in 20 mg, 40 mg, 60 mg, 80 mg, and mg doses.
Their decision often depends on:. Work with your doctor to ensure Viagra is a safe choice for you. If your blood pressure drops, symptoms like dizziness, lightheadedness, and headache could also hinder your hard-on and mood.
Need a little help? It depends on individual factors. Typically, Viagra can last up to 4 hours , but many users say it begins to wear off within 2 or 3 hours. Some have reported it lasting up to 5 hours.
Like Viagra, most ED drugs can be taken 30 to 60 minutes before sex. The exception is Stendra avanfil , which is the fastest-acting ED medication available. It only takes 15 to 30 minutes to kick in, depending on the dose. When it comes to duration, Cialis tadalafil is the longest lasting and works for up to 36 hours.
Viagra works by increasing blood flow to the penis so you can get hard enough, long enough to engage in sexual activity. Below are the most common side effects of Viagra. Talk with your doctor if you experience any of these symptoms for an extended period of time:. Stop taking Viagra and call or your local emergency services, or go to the nearest emergency room, if you experience any of these symptoms:.
In some cases, your doctor may recommend trying it over the course of a few weeks or months , depending on your condition. Resist the urge to take Viagra recreationally. Recreational Viagra is a thing, and so is counterfeit Viagra. Both are risky and can lead to a lot bigger and scarier side effects than a raging monster of a hard-on.
A doctor will prescribe the safest and most effective dose based on your health and needs. An online retailer or some dude at the bar, not so much. When taken as prescribed, Viagra can help you get hard so you can engage in sexual activity but do not expect it to do all the work. Take it as directed and make sure to help it along by being sufficiently turned on when you use it.
The most common side effects are headaches, feeling sick, hot flushes and dizziness. Many men have no side effects or only mild ones. It can be dangerous to take sildenafil if you also take medicines called nitrates often given for chest pain.
The combination can cause a dangerous fall in your blood pressure. If you're not sure if you're taking a nitrate, ask your doctor or pharmacist. Sildenafil is called by the brand names Viagra for erectile dysfunction and Revatio for pulmonary hypertension.
Sildenafil is not suitable for some people. Do not take sildenafil if you: have had an allergic reaction to sildenafil Viagra or any other medicines in the past are taking medicines called nitrates for chest pain have a serious heart or liver problem have recently had a stroke or a heart attack have low blood pressure have a rare inherited eye disease, such as retinitis pigmentosa Check with your doctor before taking sildenafil if you: have sickle cell anaemia an abnormality of red blood cells , leukaemia cancer of blood cells or multiple myeloma cancer of bone marrow have a deformity of your penis or Peyronie's disease curved penis have a heart problem.
Your doctor should carefully check whether your heart can take the additional strain of having sex. Private prescription You can also get sildenafil on a private prescription from your doctor. From a pharmacy You can buy sildenafil from a pharmacy following a discussion with the pharmacist.
It's important to take it as advised by your doctor or pharmacist. How much will I take for erectile dysfunction? The usual dose is 50mg, when you need it no more than once a day. The dose can be increased to mg or decreased to 25mg depending on its effect. How much will I take for pulmonary hypertension?
The usual adult dose is 20mg taken 3 times a day. Doses for children can range from 10mg to 20mg taken 3 times a day, depending on their weight.
How to take it Swallow tablets whole with a glass of water or juice but not grapefruit juice. Liquid sildenafil If you or your child are taking sildenafil as a liquid, 1ml is usually the same as taking a 10mg tablet, but it's important to always check the medicine label.
Liquid sildenafil will usually be made up for you by your pharmacist. The medicine will come with a plastic syringe or spoon to help you take the right amount. What if I forget to take it? Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you. What if I take too much? Taking too much sildenafil by accident can cause unpleasant side effects, such as: headaches dizziness indigestion blocked nose altered vision Talk to your doctor if you have taken too much sildenafil and you're worried about these side effects.
Common side effects Common side effects happen in more than 1 in people. If you get these side effects, keep taking the medicine, but tell your doctor or pharmacist if these side effects bother you or do not go away: headaches feeling sick hot flushes, including facial flushing indigestion a colour tinge to your vision or blurred vision stuffy nose dizziness Serious side effects Serious side effects are rare and happen in less than 1 in 1, people.
Stop taking sildenafil and call a doctor straight away if you get : chest pains - if this happens during or after sex, get into a semi-sitting position and try to relax; do not use nitrates to treat your chest pain prolonged and sometimes painful erections - if you have an erection that lasts for more than 4 hours, contact a doctor immediately a sudden decrease or loss of vision a serious skin reaction - symptoms may include fever, severe peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes seizures Serious allergic reaction In rare cases, it's possible to have a serious allergic reaction anaphylaxis to sildenafil.
These are not all the side effects of sildenafil. For a full list, see the leaflet inside your medicines packet. Information: You can report any suspected side effect to the UK safety scheme. Sildenafil is not recommended in pregnancy and while breastfeeding. Non-urgent advice: Tell your doctor if you're:.
Some medicines do not mix well with sildenafil. Tell your doctor if you're taking these medicines before you start sildenafil : nitrates for chest pain riociguat for pulmonary hypertension recreational drugs called poppers, such as amyl nitrite Mixing sildenafil with herbal remedies and supplements Some complementary therapies may have ingredients that could interfere with sildenafil and cause side effects.
Important Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements. How does sildenafil work?
Sildenafil belongs to a group of medicines called phosphodiesterase 5 PDE5 inhibitors. This increases the blood supply to the lungs and reduces the workload of the heart.
How well does it work for erection problems? Sildenafil works well for erectile dysfunction. In general, at least two-thirds of men say they have harder erections after taking it. If sildenafil does not work for you, it may be because: you have not waited long enough after taking it before trying to have sex you have waited too long after taking it to have sex the dose is not high enough you're not sexually aroused enough.
How long does it take to work? Sildenafil usually starts to work within 30 to 60 minutes. It's triggered by sexual stimulation, so you need to be aroused for it to work.
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