What to expect when you use treatment for erectile dysfunction

Erectile dysfunction (ED) is when you can’t get or keep an erection (1). ED isn’t something to be ashamed of. It’s very common, particularly in males over 40 years old (1). ED treatment can help (1). You can get more information or request ED treatment using our service..

What is ED?

ED stands for erectile dysfunction (1). This is also known as impotence, although this term is used less (1).

ED is when a person can’t:

• Get an erection when sexually stimulated (1)
• Keep an erection for long enough to have sex (1)

They may still get an erection when they wake up or at other times (1). This depends on the cause (1).

What is ED caused by?

Most males occasionally struggle to get or keep an erection (1). This can be due to tiredness, stress, drinking too much alcohol, or a side effect of some medicines (1).

ED is can be caused by:

• Hormone problems such as low testosterone (1)
• High blood pressure (1)
• High cholesterol (1)
• Diabetes (1)
• Depression (1)
• Anxiety (1)

What can help with ED?

Making changes to your lifestyle can help with ED (1).

This can include:

• Stopping cigarette smoking (1)
• Drinking less alcohol (no more than 14 units of alcohol per week) (1)
• Eating a healthy, balanced diet (1)
• Losing weight, if you are overweight (1)
• Exercising regularly (ideally every day) (1)
• Trying to reduce anxiety and stress (this could be through exercise, meditation, or treatment like therapy or medicines) (1)

There are also ED treatments available (1).

What are the different types of ED treatment?

The main ED treatments are tablets and include:

• Tadalafil (also found as brand name Cialis) (1)
• Sildenafil (also found as brand name Viagra) (1)
• Vardenafil (also found as brand name Levitra) (1)
• Avanafil (currently only available as brand name Spedra) (1)

ED tablets are widely used and are usually the first line of treatment we would try (2).

There are also injections available, including:

• Invicorp (2)
• Alprostadil (used to be called Caverject) (2)
• Viridal (2)

These medicines are injected into the base of the penis, special training is needed before a person can use these medicines (2).

There are also treatments that are applied to the skin available:

• Vitaros (2)
• Eroxon Stimgel (2)

These creams are applied either to the hole or the head of the penis (2).

Vacuum pumps are also another option if medicine isn’t suitable or doesn’t work (1). They encourage blood to flow to the penis, causing an erection (1).

Do you need a prescription for ED tablets?

You’ll usually need a prescription for ED tablets. Our clinical team will be able to help work out if treatment is right for you and which one might work best.

Awkward as it might feel, there is nothing to be ashamed of. Our team are not here to judge - we have these conversations every day and honestly just want to help.

How do ED tablets work?

ED tablets help cause an increase in blood flow to the penis (2) but they don’t:

• Work instantly (2)
  • 2.5mg or 5mg tadalafil (Cialis) tablets that are taken daily can take up to 2 weeks to start working (3)
  • 10mg or 20mg tadalafil (Cialis) tablets that are taken each time you plan to have sex should be taken at least 30 minutes before sexual activity (3)
  • Sildenafil (Viagra) tablets should be taken at least 30 minutes before sexual activity (though they can sometimes take up to an hour to work) (4)
• Create erections automatically
  • After waiting for the medicine to work, you will need to stimulate yourself sexually or be sexually excited (aroused) by a partner to get an erection. (3) The medicine won’t work if you don’t do this. (3)

Which ED tablets are right for me?

ED tablets aren’t always suitable for everyone. You can discuss the different treatment options with us. We can help you understand which treatment may be best for you.

For example, Tadalafil (Cialis) might be the right choice for a person who:

• Hasn’t tried ED treatment before (3)
• Has tried ED treatment before, but is looking for something that lasts longer (3) - 1 dose can last up to 36 hours (3) compared with other ED treatments that usually last around 4 hours (4)
• Would like a more relaxed and spontaneous sex life - the lower-strength tablets are taken daily, which means erections can happen whenever needed (3)

However, ED tablets work differently depending on the person. We work with you to find what works for you and adjust if needed. ED medicines can be changed easily with our supervision (4).

How do you use tadalafil (Cialis)?

Tadalafil can be taken with or without food (3).

There are two different forms:

1. 2.5mg and 5mg tablets ⁽³⁾
   • 1 tablet should be taken every day, whether someone has sex or not ⁽³⁾
     • This is so the medicine is always in their body and is continuously working ⁽³⁾
     • This means whenever they’re aroused and sexually stimulated, they can get an erection ⁽³⁾
   • We may consider these tablets if a person experiences ED regularly and enjoys sex 2 to 3 times per week ⁽³⁾
   • If someone takes Tadalafil every day for the first time, it can take up to 2 weeks to start working ⁽³⁾
2. 10mg and 20mg tablets ⁽³⁾
   • 1 tablet should be taken at least 30 minutes before sex ⁽³⁾
     • After waiting for the medicine to work, you’ll need to stimulate yourself sexually and be aroused to get an erection ⁽³⁾
     • The medicine won’t work if you don’t do this ⁽³⁾
   • We might consider these tablets if someone:
     • Only experiences ED sometimes ⁽³⁾
     • Doesn’t want to take a tablet every day ⁽³⁾

How do you use Sildenafil (Viagra)?

You should take a tablet at least 30 minutes before sex (4). Sometimes it can take up to an hour to work (4). It’s best to take it without food and when you haven’t eaten in a while (on an empty stomach). Food can cause a delay in the tablets working, but shouldn’t stop them from working.

After waiting for the medicine to work, you’ll need to stimulate yourself sexually and be aroused to get an erection (4). The medicine won’t work if you don’t do this (4).

If you haven’t used Sildenafil before, it’s best to start with a 50mg dose (4). If you struggle to get an erection or it doesn’t last long enough, we will likely recommend increasing to a 100mg dose (4). In this case, you can take two 50mg tablets or one 100mg tablet (4).

You can’t take more than 100mg at one time, and you can only take this medicine once every 24 hours (4).

How long do Tadalafil (Cialis) and Sildenafil (Viagra) last?

Tadalafil (Cialis) can last up to 36 hours (3). Sildenafil (Viagra) lasts for about 4 hours (4). This means, during this time, if you sexually stimulate yourself and are aroused, the treatment will help you get an erection (3).

What are the side effects of Tadalafil (Cialis)?

Some common side effects of Tadalafil (Cialis) include (5):

• Headaches (5)
• Red skin on the face, neck, or upper chest (flushing) (5)
• Pain, discomfort, or bloating in the tummy (gastrointestinal discomfort) (5)
• Stuffy or blocked nose (nasal congestion) (5)
• Muscle aches and pains (myalgia) (5)

You can speak to a pharmacist or doctor about the side effects of treatment. Always report any side effects you experience to a healthcare professional.

What are the side effects of Sildenafil (Viagra)?

Some common side effects of Sildenafil (Viagra) include:

• Headaches (6)
• Cough (6)
• Hair loss (alopecia) (6)
• Anxiety (6)
• Feeling dizzy or like you’re going to be sick (nausea) (6)
• Night sweats or trouble sleeping (insomnia) (6)
• Stuffy or blocked nose (nasal congestion) (6)
• More often, loose, or runny poos (diarrhoea) (6)
• Increased risk of infection (6)
• Skin reactions or swelling (fluid retention) (6)
• Uncontrollable shaking in one or more parts of your body (tremor) (6)
• Low blood pressure (vasodilation) or lack of healthy red blood cells (anaemia) (6)
• Problems with eyes and sight (vision disorders) (6)

You can speak to a pharmacist or doctor about the side effects of treatment. Always check any side effects you’re worried about with a healthcare professional.

What should I do if ED tablets don’t work?

Even if you have taken the medicine correctly and are aroused, you may not always get an erection or it may not last long enough for sex. Speak to our team by phone or email if your treatment isn’t working.

Some of the things we may talk to you about include trying:

• The same treatment a few more times
• Treatment at a different time of the day
• The same treatment with a different amount of medicine in it (different strength, usually in mg)
• A different treatment

It’s completely normal for a treatment to not be quite the right fit the first time, we always work with you to find what’s right.

Where can I buy ED treatment?

You usually need a prescription to get ED treatment like Sildenafil (Viagra) and Tadalafil (Cialis).

You can request treatment directly through our service:

1. Select your medical condition or a suggested treatment
2. Click ‘Start my online consultation’
3. Fill in the online consultation

We are a team of UK-based pharmacists who can help you access safe, regulated treatment. We know that seeking treatment for any condition can be daunting. This is why we’re always discreet, professional, and understanding. We can give you advice and answer any questions you may have.

Where can I find out more?

1. Erectile Dysfunction [Internet]. NHS. 2023 Jul 28.
2. Erectile Dysfunction Treatment [Internet]. Oxford Online Pharmacy. 2024 Feb 28.
3. Tadalafil Tablets [Internet]. Oxford Online Pharmacy. 2024 Nov 07.
4. Sildenafil Tablets [Internet]. Oxford Online Pharmacy. 2024 Mar 27.
5. Tadalafil [Internet]. NICE (National Institute for Health and Care Excellence) BNF (British National Formulary). 2025.
6. Sildenafil [Internet]. NICE (National Institute for Health and Care Excellence) BNF (British National Formulary). 2025.