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Home/Erectile dysfunction/Sildenafil



Medically equivalent to Viagra®, but at a fraction of the cost

Our most popular E.D. treatment. Sildenafil is the active ingredient in Viagra, just without the brand name. The more cost effective way for easier erections. Clinically proven and used by millions worldwide.
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How do our discounts work?
Final treatment plans are shared decisions determined with your clinician after this online assessment. Always read the leaflet and treatment plan.

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Ongoing clinician support

How to use Sildenafil

Get in the mood

You still need to be sexually aroused for it to work, so everything needs to be exciting. You’ve got this.

Take the pill

Take a pill an hour before you want to have sex. Sildenafil starts to work within 30-60 mins and maximum erection potential happens around the 1 hour mark.


Sildenafil lasts for around 4 hours (sometimes longer for some men). So relax, no need to rush.

A note from our doctor

Erections really aren’t that easy. For a lot of men. About 40% of men have erection difficulties by age 40. But help is here. Sildenafil is one option for men with E.D. and lasts for around four hours. Whatever the cause, it helps for the vast majority of men.
Earim Chaudry
Medical Director
Your manual to sildenafil
4-5 hours
Onset of action
60 minutes
Available in
50mg, 100mg
Don’t combine with
Alcohol, Nitrates
Cost-effective, most popular, on-demand dosing
Speak to us if you have
Hypotension (blood pressure <90/50 mmHg), recent stroke or heart attack

How it works

Quick questionnaire

We’ll ask you a couple of quick medical questions. Tick the boxes and a clinician will review your answers and issue you a prescription.

Free next-day delivery

Your selected treatment will be delivered for free, with discreet packaging and instructions on how to use it.

Clinician support

Chat with a medical expert whenever you need. On the phone or via email. With support throughout your treatment.

Money Back Guarantee
If your treatment doesn’t work we will give you a full refund on your purchase. See terms
Not sure what the best treatment is for you?
Start our free online consultation for the best treatments specifically tailored to you.
Dr Earim Chaudry
Medical Director
Frequently asked
Is Sildenafil the same as Viagra?

Sildenafil citrate is the active ingredient in branded Viagra, which you can now buy as generic Sildenafil tablets from Manual. Without the famous brand name behind it, Sildenafil is still a successful treatment for erectile dysfunction and will give you the same effects as Viagra, but without the higher price tag.

How does Sildenafil work?

Sildenafil is a PDE5 enzyme inhibitor, meaning it works by allowing blood vessels to expand and relax. This increases blood flow to the penis when a man is aroused, which improves sexual performance for men with erectile dysfunction (ED). Sildenafil and Viagra work in exactly the same way, because the active ingredient (sildenafil citrate) is the same.

How long does Sildenafil last?

For most men, the effects of Sildenafil can last for up to 4-5 hours, although it can range from 2-6 hours depending on the individual. Sildenafil can safely be used daily, if you’re intending to have sex daily, however, the effects of Sildenafil don’t accumulate if you take more in advance. Use it only when you need it.

How long does it take for Sildenafil to work?

Sildenafil usually starts to work within 30-60 minutes. Maximum erection potential is usually after 1 hour. It’s important to remember that the pill won’t give you an automatic erection – you still need sexual stimulation to maintain a good erection. Eating a heavy meal or drinking too much alcohol before taking Sildenafil can also mean the drug is slower to take effect.

How effective is Sildenafil?

It’s suggested that 80% of men who take Sildenafil achieve erections strong enough for sex. In a review of 82 trials covering over 47,000 patients, Sildenafil 50mg was found to be the most effective of all other comparable medications. Hence why it's our treatment of choice here at Manual.

How to order Sildenafil tablets?

You can order Sildenafil tablets online in minutes. You'll just need to follow these steps: 

  • Get started by selecting your desired strength, frequency, and the number of pills. If you’re unsure, get in touch with us.
  • Confirm in our questionnaire that you’re over 18, you need the medicine, and you’ll be the one using it.
  • Declare that you don't have a history of heart disease, Peyronie's disease, high blood pressure, stomach ulcers, or other relevant medical conditions. If you do have any of these conditions, we’ll be unable to sell you Sildenafil. Please get in touch with us about your options.
  • Confirm that you’re not using medicines including nitrates, alpha-blockers, Riociguat, or poppers. 
  • Enter your address and check out. You'll receive Sildenafil in a discreet package straight to your door.
Why choose Sildenafil?

Sildenafil is a highly effective treatment for erectile dysfunction. It's an excellent choice for men who want reliable erection support but don't want to pay for a famous brand name. 

Sildenafil is effective in 80% of men, while less than 2% of users report adverse effects. 

As an alternative, try Cialis or generic Tadalafil, a PDE5 inhibitor that works in the same way as Sildenafil. They call it the 'weekend pill' because its effects are felt for up to 36 hours, instead of 4 hours with Sildenafil. Some men prefer it as it offers more flexibility — you won't have to pop a pill every time before sexual activity.

Is it safe to obtain Sildenafil online?

It is safe to obtain Sildenafil online. But you should be careful where you buy it. Viagra and other ED treatments are some of the most counterfeited drugs globally, and the trouble with the internet is you can't always be sure what you’re buying is the real deal.

Only buy drugs, including Sildenafil, from a registered, accredited pharmacy. Look for the Registered Pharmacy Logo and number. Manual’s is 9012134.

Can I buy Sildenafil without a prescription?

Yes, you can buy Sildenafil without a prescription. But you’ll have to answer a few questions from the pharmacist first. These include questions about your medical history, such as any medical conditions you may have or medications you’re currently taking.

Can Sildenafil tablets be divided?

We do not recommend dividing Sildenafil tablets. They’re designed to be taken whole, so you know exactly how much you’re taking. 

If you need a smaller dose, get in touch with us. 

Can I drink with Sildenafil?

You can drink with Sildenafil, but we recommend that you keep alcohol consumption to a minimum. That's because alcohol can exacerbate the medication’s possible side effects. 

We get that you might want a glass of wine or two to get in the mood. And a small amount probably won't hurt. But side effects can be serious and, at the very least, they can spoil the fun.

What should I do if Sildenafil does not work or stops working?

If Sildenafil does not work, try taking it at least a couple of hours after a meal. Fatty foods can slow down the onset of the drug, meaning you might miss optimal timings.

Remember, it's best if you take Sildenafil about an hour before sex to ensure that it’s fully absorbed.

We recommend that you try treatment eight different times before trying another ED treatment. This does not apply if you experience serious side effects, in which case you should stop immediately. 

If Sildenafil stops working, it may mean a couple of things: 

  • Your Sildenafil has expired. If Sildenafil passes its shelf life, it may not work as effectively.
  • Your body has changed. This can happen if you take Sildenafil for many years. If this is the case, try a different ED medication, like Tadalafil.
  • The causes of your erectile dysfunction have worsened. In some cases, the artery supplying your penis may be blocked completely.

If Sildenafil stops working, talk to a Manual clinician. We can help.

“It’s put a spark back into my relationship and given me a huge amount of confidence in the bedroom.”
Anthony, Trustpilot
Meet our medical team
Enabling the mission of revolutionising how men approach health, they are at the core of the men’s wellness platform. Meet our team.
Earim Chaudry, MD
Medical Director
Eve Agwuncha
Pharmacist, Ind. Prescriber
Bentley Ifediora-Ezike
Pharmacist, Ind. Prescriber
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Sildenafil: Everything You Need to Know
Curated by Dr. Earim Chaudry, Manual Medical Director
At Manual, we are experts on erectile dysfunction. There are many causes of ED, generally split into psychological or organic causes (such as medications, hormonal, neurovascular, anatomical factors). In many patients, it can be caused by a combination of factors, and so do we advise having a GP checkup.
If you decide to treat your ED, an oral medication like Sildenafil is the most popular way to start. Some men find just knowing it’s available to help improves their sexual confidence, and 80% of men who take Sildenafil will achieve erections strong enough for sex. Those are good odds.
When and how should I start treatment?
Here at Manual, all of our medication comes from the officially accredited Manual Pharmacy. Before you buy, you will receive a consultation from one of our clinicians, who are all registered with the UK’s General Pharmaceutical Council.
Our pharmacist will prescribe you the correct dose of Sildenafil to best treat your ED. The normal dosage of Sildenafil is 50mg, and this has the desired effect for the vast majority of men who use it. It can also be taken in 25mg and 100mg forms.
When you take Sildenafil for the first time, the most important thing is to relax and enjoy some sexual stimulation. This will give the drug the best chance to kick in and help you get the firm erection you’re looking for. Learn more about first-time use of Sildenafil on our blog.
Can I buy cheap Sildenafil online in the UK?
Sildenafil is the world’s most counterfeited drug – and there are many online vendors trying to pull a fast one. So if it looks like too much of a good deal, it most likely is.
Sildenafil was first brought to the UK market by global pharmaceutical giants, Pfizer, and it was only available under their brand name, Viagra. This exclusivity meant the price tag was high and many men couldn’t afford this type of legitimate ED medication.
In 2013, however, Pfizer’s patent expired, and it became legal to manufacture the drug under its generic name, Sildenafil.
Here at Manual, we provide a digital consulting service. The recommended retail price for branded Viagra Connect is equivalent to about £5 per pill. At Manual, the same Sildenafil is available for as little as £2 per tablet.
What are the common side effects of Sildenafil?
Firstly, it’s important to know that side effects are rare. However, when they do occur, the most common side effects of Sildenafil are: headaches, facial flushing, indigestion, nasal congestion, dizziness, nausea, hot flushes, vision changes (such as having a blue colour tinge, or blurred vision).
Serious side effects can become more common when Sildenafil is misused, mixed with excessive alcohol, or due to drug interactions with other medications. Although rare, Priapism (an erection that lasts for 4 hours or more) is a serious side effect that requires immediate medical attention.
Please read the patient information leaflet carefully for a full list of side effects and advice. As with any drug, if you notice any adverse effects, stop taking it and seek medical advice.
Who shouldn’t take Sildenafil?
Women should never take Sildenafil, and nobody under the age of 18 – male or female. And, of course, if you don’t have erectile dysfunction, you shouldn’t use Sildenafil.
If you’ve been told by the doctor not to have sex – perhaps due to lack of fitness or a recent acute myocardial infarction (AMI) or stroke, you should also avoid Sildenafil. And generally, men who have had other heart problems needing care. These include: low blood pressure or uncontrolled high blood pressure (pulmonary arterial hypertension); unstable angina (chest pain), irregular heartbeat or palpitations (arrhythmia); valvular heart disease; cardiomyopathy; problems causing blood flow issues.
Other conditions may prohibit the use of Sildenafil, such as anatomical deformation of the penis (e.g. Peyronie's disease); loss of vision in one eye due to non-arteritic anterior ischaemic optic neuropathy (NAION) or hereditary degenerative retinal disorders like retinitis pigmentosa; severe renal impairment; any of the following: sickle cell anaemia, multiple myeloma or leukaemia, or active stomach ulcers.
And you should also confirm with your GP if you’re taking nitrates (nicorandil or other nitric oxide donors e.g. isosorbide mononitrate, isosorbide dinitrate); ‘poppers’ (e.g. amyl nitrite), or recreational stimulant drugs (e.g. cocaine, MDMA); riociguat or other guanylate cyclase stimulators; ritonavir; CYP3A4 inhibitors, e.g. saquinavir; cimetidine; itraconazole or ketoconazole; erythromycin or rifampicin; diltiazem; alpha-blockers; doxazosin or tamsulosin.
Before using Sildenafil, please read the Patient Information Leaflet supplied with your medication. This provides important information.
Are there alternatives to Sildenafil?
The Sildenafil in Viagra is one of a number of PDE5 enzyme inhibitors. Alternatives include Tadalafil (Cialis), Vardenafil (Levitra) and Avanafil (Spedra) – for which you do still need a prescription.
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