Sildenafil (Viagra)

What is Sildenafil?

Sildenafil is a medicine used to treat erectile dysfunction (ED) in adult men. It contains sildenafil citrate, a well-established medication that has been used worldwide for many years to help men achieve and maintain erections firm enough for sexual activity.

Generic sildenafil contains the same active ingredient used in the original branded medicine Viagra and is manufactured to the same regulatory quality standards.

Because it's available as a generic medicine, sildenafil can often be a more affordable treatment option. It is taken only when needed rather than every day and works alongside natural sexual stimulation to support the body's normal erectile response.

How Does Sildenafil Work?

Sildenafil works by improving blood flow to the penis during sexual arousal. It belongs to a group of medicines called phosphodiesterase type-5 inhibitors (PDE5 inhibitors). PDE5 is an enzyme that acts on the blood vessels involved in an erection.

When a man becomes sexually stimulated, the body releases nitric oxide. This triggers a chain reaction that relaxes smooth muscle in the blood vessels of the penis, allowing more blood to flow in and create an erection. The PDE5 enzyme normally breaks down this signal, limiting how long the erection lasts.

Sildenafil blocks the PDE5 enzyme, helping the blood vessels remain relaxed for longer. This improves blood flow and makes it easier to achieve and maintain an erection for sex.

Sildenafil doesn't cause an erection automatically, and sexual stimulation is still required for the medicine to work. Once the medicine's effects wear off, erectile function returns to normal.

How Long Does Sildenafil Take to Work?

In most men, sildenafil begins working within 30 to 60 minutes. Sildenafil doesn't cause an erection on its own; sexual stimulation is still required. As such, you should still engage in masturbation or foreplay as you normally would. Strict timing isn't necessary, as sildenafil's effects can last up to 4 hours.

As with any erectile dysfunction medication, it may not work the first time you use it. Take some time to work out how sildenafil works best for you. Try to relax and be open to trying again another day. You should not take more than one dose of sildenafil a day.

Does Sildenafil Work for Erectile Dysfunction?

Sildenafil is one of the most extensively studied treatments available for erectile dysfunction. It has been tested in thousands of men across a wide range of ages, health conditions and severity levels of ED.

One clinical trial found that the average total duration of an erection firm enough to engage in sexual intercourse was 19.4 minutes, compared to just 3.9 minutes when using a placebo. Participants were tested two hours after taking 100 mg of sildenafil. Meanwhile, the median duration of an erection 4 hours post-dose was 5 minutes for sildenafil and 0 minutes for placebo.

Another study comparing 50 mg of sildenafil and a placebo noted that 82% of people in the sildenafil group managed an erection of over 60% rigidity, compared to 53% in the placebo group. The median amount of time needed to achieve an erection was just 27 minutes with sildenafil, compared to 50 minutes with the placebo.

A third trial gave participants a flexible dose of sildenafil between 10 mg and 100 mg an hour before intercourse. It recorded that 93% of men experienced improved erections. The second phase then randomly assigned participants to either continue with sildenafil or change to a placebo. Those who remained with sildenafil continued to experience significant improvements in the frequency and duration of erections, while participants in the placebo group returned to pre-treatment values.

When taken correctly, sildenafil provides a reliable and effective treatment option for many men experiencing erectile dysfunction. Individual results may vary, but most men experience a meaningful improvement in erectile function.

How to Take Sildenafil

Sildenafil should be taken around 1 hour before sex. Swallow the tablet whole with water. Sexual stimulation is required for the medicine to work, as sildenafil supports the body's natural erection process rather than causing an erection on its own. Always take sildenafil as your prescriber advises.

Avoid heavy or high-fat meals shortly before taking sildenafil. Large meals can slow absorption and delay how quickly the medicine starts working. Avoid grapefruit juice whilst taking sildenafil as this can increase drug levels in the blood. Do not take sildenafil film-coated tablets in combination with sildenafil orodispersible tablets.

How Should I Take Sildenafil for Best Results?

Take sildenafil exactly as prescribed by your clinician. To maximise the benefits of sildenafil, keep the following in mind:

• Avoid heavy/fatty meals before using sildenafil, as this can delay its onset
• Limit or avoid alcohol use, as alcohol can make it harder to achieve and maintain an erection
• Engage in foreplay as you normally would (sildenafil doesn't cause an erection without sexual stimulation)
• Relax and take your time. Undue pressure can make it more difficult to get an erection.
• If it doesn't work, don't worry. You can try again on another day.

Sildenafil Dosage Information

The usual dose of sildenafil for erectile dysfunction is 50 mg taken when needed before sexual activity. Do not take more than one dose a day. Your prescriber may adjust your dose according to your response. They may recommend anywhere between 25 mg and 100 mg (maximum), depending on the results.

If sildenafil does not help you get an erection or your erection does not last long enough for sex, speak to your prescriber.

Can You Take Sildenafil Daily?

You cannot take more than one dose a day. There is no restriction on taking sildenafil on consecutive days. As long as you can tolerate the medication well, and your prescriber has not advised you to take a break between uses, sildenafil can be used daily. Remember, you should only take this medication before sex.

If You Take Too Many Sildenafil Tablets

If you take more sildenafil than you should, you may experience an increase in side effects and their severity. Do not take a higher dose of sildenafil than your prescriber recommends. Doses over 100 mg do not improve efficacy.

If you have taken too much sildenafil, contact your doctor straight away.

Sildenafil Side Effects and Cautions

Sildenafil is a well-tolerated erectile dysfunction treatment in most men. However, it may not suit everyone. Take a moment to review the following safety and side effect information.

Possible Side Effects of Sildenafil

As with any medication, certain side effects are associated with sildenafil use. Not everyone who takes sildenafil will experience side effects. Contact your prescriber if you experience any of the following:

It's important to note that the table above does not contain a complete list of possible Sildenafil side effects. For more details, please consult the Patient Information Leaflet enclosed with the treatment. If you experience any adverse reactions while taking the medication, you can report them to your clinician or use the MHRA's Yellow Card Scheme.

Serious Sildenafil Side Effects

Severe side effects associated with sildenafil use are uncommon, but they do occur. Stop taking sildenafil and seek immediate medical assistance if you experience any of the following:

• An allergic reaction. Symptoms include wheeze, difficulty breathing, dizziness, and swelling of the eyelids, face, lips, or throat.
• Chest pains. If this occurs during or after intercourse, get into a semi-sitting position and seek emergency medical attention. Do not use nitrates to treat your chest pain.
• Prolonged and sometimes painful erection that lasts longer than 4 hours.
• A sudden decrease or loss of vision
• Serious skin reactions. Symptoms include skin peeling, swelling, fever, and blistering of the mouth, genitals, and around the eyes.
• Seizures (fits)

Sildenafil Warnings and Interactions

Sildenafil may be prescribed to adult men who have erectile dysfunction. However, it is not suitable for everyone. It shouldn't be used by people taking nitrate medicines, those with certain heart conditions, severe low blood pressure or certain rare eye disorders. Before treatment, a clinician will review your medical history.

Do not take Sildenafil pills if:

• You are allergic to sildenafil or any other ingredient in this medication
• You have a severe heart or liver problem
• You have recently had a stroke or heart attack
• You have been advised by your doctor to avoid sexual activity because of problems with your heart or blood vessels
• You have low blood pressure
• You have certain rare inherited eye diseases such as retinitis pigmentosa
• You have ever had loss of vision due to non-arteritic anterior ischaemic optic neuropathy
• You do not have erectile dysfunction
• You are a woman

Precautions Before Taking Sildenafil

Before taking sildenafil for the first time, your prescriber will review your medical history and current medication usage to determine whether it is right for you. Tell your prescriber if any of the following apply to you:

• You have sickle cell anaemia or leukaemia
• You have a deformity of your penis or Peyronie's Disease
• You have problems with your heart. Your doctor should assess whether your heart can manage the additional strain of sex
• You currently have a stomach ulcer or bleeding problem
• You have kidney or liver problems
• You have multiple myeloma

Sildenafil and Other Medicines

Tell your prescriber if you are taking or have recently taken any other prescribed medicines, over-the-counter products, supplements, or herbal remedies.

Do not take sildenafil if you take:

• Nitrate medicines. These include medicines to treat chest pain and heart failure (such as glyceryl trinitrate or isosorbide mononitrate), recreational drugs known as 'poppers' (alkyl nitrites), nicorandil, and sodium nitroprusside
• Riociguat or other guanylate cyclase stimulators (used to treat high blood pressure in the lungs)
• Sildenafil or another PDE5 inhibitor for the treatment of pulmonary arterial hypertension
• Another erectile dysfunction medication (discuss this with your prescriber)

Sildenafil may not be right for you if you take certain medications. Your prescriber may want to adjust your dose or offer an alternative treatment if you take any of the following:

• Medicines containing sacubitril/valsartan (used to treat heart failure)
• Some medicines to treat chest pain. In the event of a medical emergency, tell your doctor that you have taken sildenafil
• Medicines known as protease inhibitors (used in the treatment of HIV)
• Alpha-blockers (used for the treatment of high blood pressure or prostate enlargement)

Sildenafil contains lactose. This medication may not be suitable if your doctor has told you to avoid certain sugars.

Where to Buy Sildenafil in the UK

You can only buy sildenafil from a licensed pharmacy in the UK. Generic sildenafil requires a prescription from an appropriately trained prescriber. At Prescription Doctor, our expert clinicians will review your confidential online consultation to determine whether sildenafil is the right erectile dysfunction treatment for you.

Can You Get Sildenafil Over the Counter?

While you cannot buy generic sildenafil over the counter, several branded options are available to purchase after a discussion with a pharmacist (without a prescription). These include Viagra Connect and Perrigo Sildenafil. However, these medications are only available in a 50 mg fixed dose.

At Prescription Doctor, you can choose between over-the-counter and prescription sildenafil. Regardless of which option you choose, our expert clinicians will review your medical history and current medication use to ensure your treatment selection is right for you.

Are Sildenafil Pills Available on the NHS?

Generic sildenafil can be prescribed on the NHS for erectile dysfunction. Whether it is prescribed for you will depend on your individual circumstances and local prescribing arrangements. By using a reputable online pharmacy, you can access a wide range of erectile dysfunction treatments without the need for an in-person consultation.

Can You Buy Sildenafil Online?

Yes, you can buy Sildenafil online from trusted pharmacies like Prescription Doctor. We understand that discretion is paramount, so we dispatch our medications in plain packaging for complete confidentiality. There's no need for an appointment either, as you can obtain the medication you require in just a few clicks.

Simply complete a short medical questionnaire, and our experienced clinicians will determine whether the treatment is suitable for your circumstances. If approved, our General Pharmaceutical Council-registered pharmacy will dispatch it directly to your designated UK address. Orders approved before 3pm on a weekday are also eligible for next-day delivery.

Frequently Asked Questions About Sildenafil