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Overview

Experiencing difficulties with erections can feel frustrating and impact both confidence and relationships — but you are not alone. Erectile dysfunction (ED) is extremely common, and safe, effective treatments are available. Sildenafil is one of the most widely used and trusted options, offering a reliable way to restore sexual performance and reassurance when you need it most.

Sildenafil belongs to a group of medicines called PDE5 inhibitors, which work by increasing blood flow to the penis. When taken before intimacy, it helps support firmer, longer-lasting erections in response to sexual stimulation. This means it doesn’t cause automatic erections — instead, it gives your body the boost it needs to perform naturally.

Known for being affordable, effective, and well-studied, Sildenafil is often the first choice for men seeking ED treatment. Millions worldwide have used it with success, and it remains a go-to option for restoring confidence in the bedroom.

At SwiftMedi, every order is carefully reviewed by a UK-registered prescriber, ensuring treatment is safe and suitable for you. Medication is delivered quickly and discreetly to your door — helping you regain control without unnecessary embarrassment.

 

What is Sildenafil?

 Sildenafil is best known as the active ingredient in Viagra, but it is also available as a generic medicine. It is licensed in the UK for treating erectile dysfunction and, under the brand name Revatio, for pulmonary arterial hypertension. When you take a sildenafil tablet, it works by blocking the enzyme PDE‑5, which relaxes the blood vessels and allows more blood to flow into specific areas. For men with Erectile Dysfunction (ED), this improved blood flow helps achieve a firm erection when sexually aroused. In pulmonary hypertension, it relaxes the vessels in the lungs, reducing strain on the heart.

Sildenafil tablets are available in strengths from 25 mg to 100 mg. The typical starting dose for ED is 50 mg, taken as needed. Healthcare professionals may adjust the dose to 25 mg or 100 mg depending on how well it works and whether you experience side effects. Importantly, you should never take more than one dose in 24 hours, and you must be sexually stimulated for it to work. Sildenafil is not an aphrodisiac and will not increase desire on its own.

ED is common, affecting over half of men aged 40 to 70, and can be caused by health or lifestyle factors such as obesity, high blood pressure, smoking, alcohol consumption, and stress, as well as certain medications. Sildenafil provides a reliable and discreet solution to help improve sexual performance and confidence.

Directions

Following the advice of your prescriber will help ensure sildenafil is safe and effective. Key points to remember include:

  • When to take it: Swallow a tablet whole with water between 30 minutes and 4 hours before sexual activity. Many men find it works best on an empty stomach. A heavy or high‑fat meal can delay its onset.

 

  • Dose guidance: The usual dose is 50 mg, but your prescriber may recommend 25 mg if you are older, have liver or kidney problems, or are taking certain other medicines. Do not exceed 100 mg and never take more than one tablet per day.

 

  • Method: Do not crush or chew the tablet. Take it with a full glass of water. Avoid grapefruit juice, as it can increase the level of sildenafil in your blood and lead to side effects.

 

  • Missed or extra doses: Sildenafil for erectile dysfunction is taken only when needed. If you are using sildenafil for pulmonary hypertension and miss a dose, take it as soon as you remember unless it is nearly time for your next dose. Do not double up. If you accidentally take too much, contact a healthcare professional straight away.

 

  • Onset and duration: It usually takes 30 to 60 minutes to start working. The effects last for around 4 hours, though this can vary.

Side Effects

Sildenafil is generally well tolerated, but some men may experience side effects, including:

  • Dizziness
  • Hot flushes
  • Headaches
  • Nausea
  • Indigestion
  • Stuffy nose


Avoid grapefruit and grapefruit juice while taking sildenafil, as these can interfere with its metabolism, increasing side effects or reducing effectiveness.


Safety Information and Precautions
Sildenafil is not suitable for everyone. Avoid taking it if you:

  • Have low blood pressure or certain blood disorders
  • Take nitrate medications for chest pain (angina)
  • Have severe heart or liver problems
  • Have had a recent stroke or heart attack
  • Have penile deformities such as Peyronie’s disease


Always disclose your full medical history to a healthcare professional before starting sildenafil. It may interact dangerously with some medications, especially nitrates and alpha-blockers.

Seek immediate medical help if you experience:

  • Chest pain or allergic reactions (swelling, breathing difficulties)
  • Vision loss or severe vision changes
  • Painful or prolonged erections lasting over two hours

Warnings

Sildenafil is not suitable for everyone. Always discuss your medical history and current medications with a prescriber before starting treatment.

  • Medical conditions: Tell your prescriber if you have heart or blood vessel disease, low or high blood pressure, liver or kidney problems, vision disorders (such as retinitis pigmentosa), bleeding disorders, stomach ulcers, Peyronie’s disease, sickle cell anaemia, or if you’ve recently had a stroke or heart attack. Sexual activity can put extra strain on the heart, so seek advice if you have cardiac risk factors.

 

  • Pregnancy and breastfeeding: Sildenafil is not usually prescribed for women. If you are pregnant or breastfeeding and have been offered sildenafil for pulmonary hypertension, discuss the potential risks and benefits with your specialist.

 

  • Alcohol: Moderate alcohol consumption is unlikely to interact significantly, but heavy drinking may exacerbate side effects and hinder performance.

 

  • Medicines and interactions: Avoid taking sildenafil with nitrates (such as glyceryl trinitrate), nitric oxide donors (including recreational “poppers”), guanylate cyclase stimulators (e.g. riociguat), some antifungals or antibiotics, HIV protease inhibitors, alpha‑blockers, or other PDE‑5 inhibitors like tadalafil or vardenafil. Combining sildenafil with these medicines can cause dangerous drops in blood pressure. Always check with your prescriber before starting or stopping any medication.

 

  • Grapefruit: Grapefruit or grapefruit juice can raise sildenafil levels in the body and increase the risk of side effects. It’s best to avoid it while taking sildenafil.

 

  • Driving and machinery: If you feel dizzy or notice vision changes after taking sildenafil, wait until these symptoms pass before driving or operating machinery.

FAQ's

What is sildenafil used for?
Sildenafil is prescribed to treat erectile dysfunction and, under specialist supervision, pulmonary arterial hypertension. It increases blood flow to specific areas by relaxing blood vessels.

How long does sildenafil take to work?
Most men find that sildenafil starts working within 30 to 60 minutes. Taking it on an empty stomach may help it work faster. Sexual arousal is still required for it to be effective.

Can I drink alcohol with sildenafil?
Drinking a small amount of alcohol should not stop sildenafil from working. However, heavy drinking can reduce blood pressure and make it more difficult to get an erection, as well as increase the likelihood of side effects.

Is sildenafil the same as Viagra?
Yes. Viagra is a well‑known brand name for sildenafil citrate. Generic sildenafil contains the same active ingredient and works in exactly the same way, but it may be less expensive.

What should I do if sildenafil doesn’t work?
If you have taken sildenafil correctly on several occasions and still find it doesn’t help, speak to your prescriber. They may adjust the dose, check for underlying health conditions, or suggest alternative treatments. Do not increase the dose without medical advice.

Who should avoid sildenafil?
Men who take nitrate medicines, have certain heart or liver conditions, have severe vision or hearing disorders, or those for whom sexual activity is not advised should avoid sildenafil. Always complete a full medical questionnaire so a prescriber can assess suitability.

How often can I take sildenafil?
You should take sildenafil only once in 24 hours. Taking it more frequently increases the risk of side effects without improving its effectiveness.

Does sildenafil protect against sexually transmitted infections?
No. Sildenafil helps achieve an erection but does not protect against sexually transmitted infections such as HIV. Use condoms and practice safer sex.

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