What Is Sildenafil?

Sildenafil is a medication used in the treatment of erectile dysfunction. It is more commonly known by its most popular brand name, Viagra. It has also been found useful to treat pulmonary arterial hypertension, a condition that increases the blood pressure of the arteries in the lungs.

Sildenafil for Erectile Dysfunction


Sildenafil, at least in the form of Viagra, is one of the world’s most known drugs. The diamond-shaped blue pill’s ability to help men achieve an erection is notorious, and it has recently become even easier to procure from pharmacies in the UK, such as UK Meds.

It is prescribed to men who suffer from erectile dysfunction for all manner of reasons: due to age, because of another medical condition like diabetes mellitus, or because a side effect of other medication they are taking causes a loss of sexual drive. Use of antidepressants and many other medications also can affect a man’s libido and sexual performance, so it can be useful to prescribe Sildenafil while these issues persist.

Sildenafil works by increasing the blood flow to a man’s penis, so that they can sustain an erection for long enough to have sexual intercourse. It is medically recommended that men should take one pill (50mg or 100mg, depending on which dose is recommended to the individual by a doctor) 60 minutes before sex. The drug can take effect from an estimated 30-60 minutes after taking the pill.

Sildenafil works only when a man is stimulated sexually – contrary to popular belief, he will not suddenly achieve an erection with no stimulation. Similarly, the erection should go away after sex has finished. If it sustains, especially for more than 4 hours, he should seek medical advice. Having a continuous erection for longer than 4 hours could cause permanent damage to the penis. That is why it is vital that you only take the dose recommended for you by a doctor: overdosing on Sildenafil can cause lasting problems.

Sildenafil for Pulmonary Arterial Hypertension


Sildenafil is medically known as a phosphodiesterase-5 inhibitor. This substance (PDE5 for short) is produced in the lungs and breaks down a substance called Cyclic GMP – cyclic guanosine monophosphate – which causes arteries to widen and relax. Sildenafil works by decreasing the activity of PDE5, allowing more Cyclic GMP to reach the lungs’ arteries. This in turn decreases the blood pressure to the heart, improving its function. Blood pressure in the lungs is also reduced, allowing the patient to be more active and less restricted.

When prescribed to PAH patients, Sildenafil is sold under the brand name Revatio, usually in 20mg doses per pill.

Side Effects


Common side effects reported by users of Sildenafil include heartburn, headaches, nasal congestion, blurred vision, and flushing skin. Interestingly, some participants in the clinical trials for Sildenafil reported that their vision was ‘tinted blue’ – which is a known medical term called Cyanopsia. Less common but more serious side effects can consist of prolonged erections (seek medical advice promptly if this occurs), very low blood pressure, stroke, heart attack, and sudden loss of hearing. The United States FDA reported in 2005 that in rare cases, Sildenafil could cause vision impairment.

People taking nitrate medication – like nitroglycerin, commonly prescribed for chest pain – are warned not to take Sildenafil, which can cause blood pressure to drop dangerously low when used in conjunction. It is also not recommended for men who have cardiovascular disease.

Warnings such as these emphasise the importance of always consulting with a doctor before taking ANY medications. Use of a drug without proper knowledge of how it interacts with other medications can be a serious, and sometimes fatal, mistake. A doctor will immediately be able to advise whether a drug is safe to be taken with existing medication, and what side effects it is likely to have.



The main competitors for Sildenafil, especially in terms of ED medication, are Cialis and Levitra. Both are drugs that help men gain and maintain erections, but they work in slightly different ways, with different side effects, and their effects last for differing lengths of time.

Because of this, a person suffering from ED should consult with a medical professional who can advise which type of treatment would work best for that individual. If one type is not suitable, there may be an alternative treatment method that is.

Non-Medical Use


Due to the notoriety of Viagra for the treatment of ED in popular culture, it is a commonly recreationally-abused drug, especially in young adults. This is often due to the incorrect belief that taking the drug improves sexual drive, sexual performance, and penis size.

Studies into the recreational use of the medication show that the drug has little effect on those who do not suffer with ED. One study showed that a 25mg dose had no effect on erectile quality but did note a significant placebo effect in the control group – meaning that men who THOUGHT they had taken Viagra experienced a better sexual experience than when they took no pill.

How to Get Sildenafil


If you suffer from erectile dysfunction and think that Sildenafil or a similar drug could help you, seek advice from your doctor. They will be able to advise which dose is right for you, and whether the side effects of the drug will be tolerable for you. Contact a doctor before taking Sildenafil especially if you are on any other medication or suffer from any condition of the heart or lungs.

Besides a physical consultation with a doctor, you can obtain Sildenafil online. You should ONLY buy Sildenafil online from a trusted e-pharmacy (one that is medically certified and licenced to operate in your country). A good rule for this is to only buy from the websites of brands that you know. If you are in any doubt over the legitimacy of the online store you’re buying from, do not go through with the purchase. Fake drugs, or overdosing on a drug, can have serious adverse health effects.

Stay safe online and check consumer reviews before buying. Buying from a legitimate e-pharmacy can save you time and money: do your research and you could get your medication cheaply online!

About Maryam BenhamDr Maryam Benham obtained her medical degree in medicine in Iran in October 2004 and moved to the UK in 2006 and has held full registration with the General Medical Council since 2007. Maryam finished her foundation training at Ealing hospital and has done two years of surgery in different London hospitals such as Royal Free Hospital before deciding to pursue specialist training in General Practice at Kent, Surrey and Sussex (KSS) Deanery in 2011. Since finishing her GP training in September 2014 Maryam has been a dedicated General Practitioner in London.

With special interest in Dermatology, Aesthetics and minor skin procedures alongside her NHS work as a general practitioner, Maryam stays updated in her areas of interest through attending seminars and minor surgery and aesthetic courses. As part of the new generation of highly dedicated and skilled British doctors, Maryam believes that her main aim is to deliver the best care to her patients and to provide them with the best possible medical advice.
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