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Sildenafil

Erectile Dysfunction|Active ingredient(s): Sildenafil|Manufacturer: Various

A young man taking a blue tablet with a glass of water

Stronger erections, whenever you need.

  • Trusted by millions worldwide
  • Works in 30-60 minutes
  • Stronger erections for up to 4 hours
  • As-needed dosing
  • Available in 25 mg, 50 mg, and 100 mg doses

How to use

Close up of a man holding up a blue pill.

Choose your moment

Take your tablet 30-60 minutes before you plan to have sex.

A smiling couple looking at each other.

Set the stage

For best results, take Sildenafil on an empty stomach in an environment you feel comfortable in.

Hand touching the face of an analog clock.

Make it count

Sildenafil should last for up to 4 hours, so make the most of your time.

What others say about Sildenafil

Trustpilot review
668 reviews with score 4.7

Quality healthcare
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Price is all-inclusive.
Consultation is included.
Prescription is included.

Free shipping.
UK: Free next-day delivery.
Discreet packaging.

Licensed doctors.
Registered pharmacies.
Certified online pharmacy.

Sildenafil

What is Sildenafil?

Sildenafil is an effective treatment for erectile dysfunction. Commonly sold under the brand name Viagra, it helps many men worldwide achieve stronger erections. With its fast onset of action and straightforward dosing, millions in Europe trust Sildenafil to improve their sex lives.

How does Sildenafil work?

Sildenafil works by increasing blood flow to the genitals when you’re sexually aroused. It does this by widening blood vessels and relaxing muscle tissues in the penis, which makes it easier to get and maintain an erection.

Contrary to popular belief, Sildenafil doesn’t automatically trigger an erection. It only works in response to sexual stimulation. This means you should only feel the effects when you need to.

How effective is Sildenafil?

Clinical trials have found Sildenafil to help up to 82% of men with erectile dysfunction achieve an erection within 45 minutes.

Here are the full results of this study:

  • 71% of patients achieved an erection within 30 minutes.
  • 82% of patients achieved an erection within 45 minutes.
  • The average time erections lasted was around 20 minutes.

How long does Sildenafil take to work?

Usually, you should feel the effects of Sildenafil within 30-60 minutes of taking your tablet, with effects peaking at 1-2 hours.

This is the average effect. However, a few things can make it work faster or slower:

  • Food: Taking Sildenafil on an empty stomach can help it work more quickly, while taking it after eating a heavy meal can make it take longer.
  • Alcohol: Large amounts of alcohol can delay the effects of Sildenafil, reduce blood flow, and make it less effective.
  • Age: It may take longer for older men to feel the effects due to slower metabolism and reduced blood flow.

How long does Sildenafil last?

Sildenafil should last for around 4 hours. You can have sex multiple times during this period, and it will be just as effective as the first time.

If the effects last longer than 4 hours, or you experience an erection that doesn’t go down, seek immediate medical help.

Who can take Sildenafil?

To be prescribed Sildenafil, you must be over 18 years old and suffer from erectile dysfunction.

Do not take Sildenafil if you have:

  • An allergy to sildenafil citrate
  • A severe heart or liver problem
  • Low blood pressure
  • Recently had a stroke or heart attack

What dose should I take?

There are 3 doses of Sildenafil available. Consult this table to see which one is right for you:

Dose When it’s prescribed Who it’s prescribed for
50 mg Recommended starting dose Most healthy men aged 18-65
25 mg If 50 mg is too strong At-risk groups (over 65, liver or kidney problems, etc.)
100 mg If 50 mg is too weak Healthy adults under 65 who don’t respond to 50 mg

Can you take Sildenafil daily?

There shouldn’t be any problems if you take this medication every day, but you should consult your doctor first if you plan to use it for a long time. Daily use of Sildenafil is not usually necessary and rarely advised.

IMPORTANT:

Do not take more than 1 Sildenafil tablet per day, no matter the dose. Doing so can be dangerous.

Are there any side effects of Sildenafil?

Most people won’t experience side effects from Sildenafil, but they can happen. The most common Sildenafil side effects include:

  • headache
  • nausea
  • hot flush
  • indigestion
  • vision changes
  • stuffy nose
  • dizziness

For a full list of side effects, consult the patient information leaflet.

Will Sildenafil raise blood pressure?

Sildenafil does not typically raise blood pressure. In fact, studies show it will likely lower blood pressure, since it relaxes and widens blood vessels.

For this reason, a doctor may not prescribe Sildenafil to men currently taking nitrates or other medications that can lower blood pressure. Remember to tell your doctor about any other medicines you take in your consultation to ensure safety.

Can I buy Sildenafil without a prescription?

Safety is our number one priority at 121doc. For this reason, our doctors will only prescribe you treatment if you meet the criteria in your online consultation.

A prescription from a trusted healthcare provider like 121doc ensures:

  • safety during treatment
  • effective results
  • monitoring of side effects
Medical review byDr. Caroline FontanaLast review 19 March 2026
Dr. Caroline Fontana

Note: You must complete a short online consultation so that our doctor can ensure that the treatment is suitable for you. The above pricing should only be used as a reference. The final decision to issue this treatment lies with the prescribing doctor.

Sildenafil Overview

Type of medicine PDE5 inhibitor
Used for Erectile dysfunction
Active ingredient Sildenafil
Works by: Relaxing blood vessels and increasing blood flow to the penis when sexually stimulated
Effective within 30-60 minutes
Available as Tablets
Available dosages 25 mg, 50 mg, 100 mg
Usage instructions Take one tablet 30-60 minutes before you plan to have sex
Packaging BLister packs
Branded available? Yes, Viagra

FAQs

What is included in the online consultation?
Will a doctor review my consultation?
What happens after I submit my order?
What services are included with my order?
Is the price all-inclusive?
What are my delivery options?
Is it safe to buy prescription medication online?
Is this service discreet?
What is included in the online consultation?

Our online consultations are in the format of short medical questionnaires. You will be asked general questions about your health and medical history, as well as specific medical questions relevant to the treatment you have chosen. We will also ask you for your payment and delivery details to complete the order.

Online consultations take no longer than 5 minutes to complete. All questions are necessary when issuing prescription medicines. It means that our doctors can make sure the treatment is safe and right for you.

Will a doctor review my consultation?

Yes, it is a legal requirement that all online consultations are reviewed by a registered doctor. This is to make sure the chosen treatment is safe and right for you to take. All personal information is stored securely and confidentially.

Please note, all orders are subject to doctor approval, and we cannot guarantee that your order will be approved.

What happens after I submit my order?

Your online consultation will be sent directly to our medical team, where it will be reviewed by on of our in-house doctors.

If a doctor approves you for treatment, they will issue a prescription. Your prescription will then be forwarded to our pharmacist, where you medication will be dispensed and dispatched for delivery.

What services are included with my order?

Every order includes:

  • Free consultation - your consultation will be personally reviewed by one of our registered doctors.
  • Free prescription - a doctor will issue you a prescription if approved for treatment.
  • Free delivery - we provide free express delivery across Europe, you should receive your order in 1-2 working days.
Is the price all-inclusive?

Yes, our service is all-inclusive and there are no hidden fees. All 121doc orders include a free online consultation, a free prescription and free express delivery.

What are my delivery options?

We offer several delivery options at no extra charge:

  • Next-day delivery
  • UPS Access Point - convenient parcel drop-off and collection near your home or work address
  • Nominated-day delivery - choose the most convenient day for delivery

All these options can be tracked and require a signature on delivery. If you are not in, a friend or relative can sign in your place.

Is it safe to buy prescription medication online?

It is safe to buy prescription medications online from genuine and reputable healthcare providers, like 121doc.

Our medical staff and facilities are registered with the relevant medical governing bodies. We also ensure your data is protected by adhering to European data privacy laws.

You can learn more about our certifications here.

Is this service discreet?

Our patients’ privacy is of utmost importance. All your medical information is securely stored and only viewed by our doctors. We do not share your details with third-parties. We are also closely adhere to data privacy laws.

All orders will only show on invoices, bank statements, etc. as ‘HHC Ltd’.

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How does it work?

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Ordering:

Every order starts with an online consultation. We will ask you medical questions to make sure only treatment that is safe and effective is prescribed. We take into account your lifestyle, health and any other medications you’re currently using.

The consultation is completely free, and takes between 5 and 10 minutes of your time.

All your information is safe with us. We don’t share it with anyone unless you want us to.

Help:

If you need any guidance, you can call, message or email our customer service team via the ‘How can we help you?' section here.

Prescribe
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Review:

As soon as you place the order, one of our doctors will review your consultation. On working days, this usually takes around one hour.

Questions:

If the doctor has any additional questions, you will receive a phone call and an email. We understand you might be at work or busy. Our customer service representatives are always discreet and can call back at a more convenient time if necessary.

Our emails never contain any personal or medical information, only a link to your private account on our website (where you will find your messages).

Pharmacy:

Once our pharmacy receives your prescription, you will get a second email with your package tracking code.

Deliver
Deliver Expect your delivery the next working day.
Always free. Discreet packaging.
Free next-day delivery

Free:

All orders include next-day delivery. Alternatively, you can select a delivery date that suits you better.

Location:

We also provide a free UPS Access Point service. Pick up your package from one of many collection points across the UK.

With your tracking code, you will know the estimated delivery time. All we need is your signature (or a friend‘s or relative’s).

Discreet:

All parcels are plainly labelled; there is no logo or any indication of its contents. Inside, you will find your treatment as well as a patient leaflet in your chosen language.

Repeat
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Repeat:

With 121doc’s Subscribe & Save service, you can automatically receive your treatment every few weeks or months.

The order will be generated by us, using the information you provided (including delivery frequency). You don’t have to do anything. Payment is taken two days before shipping.

Subscribe:

There are two ways to subscribe. The first is during the order process. The second is via your profile here.

You can cancel or amend your repeat prescriptions at any time.

Save:

There are no sign-up fees with this service. Plus, you get a 10% discount off all future prescriptions, increasing to 15% after six orders!