Sildenafil Dosage Guide

Sildenafil dosage to treat erectile dysfunction

Before your doctor prescribes you with sildenafil for the treatment of erectile dysfunction they will check that you meet the eligibility criteria. 

The criteria include being a male above the age of 18 with no underlying health conditions, allergies, or medications that would make taking sildenafil unsafe.

When considering treatments for ED, it's important to explore both the psychological causes such as stress, anxiety, and depression, as well as the physical causes like smoking and excessive alcohol consumption.

Improving your health and well-being can affect how well your body responds to ED medication so it's always recommended to combine healthy lifestyle choices with your sildenafil medication. 

25mg, 50mg and 100mg of sildenafil

If you are taking sildenafil to treat erectile dysfunction there are three different dosages available - 25mg, 50mg, and 100mg.

No matter the prescribed dosage of sildenafil for treating ED, the time of onset action (30 minutes to 1 hour) and the duration of the medication’s effects will remain the same (around 4 hours).

You must also take the medication in the same way:

• Swallow the tablet whole with water (preferably without food)

• At least one hour before you plan on engaging in sexual activity

• Take no more than once in any 24 hours

Always stick to the dosage of sildenafil prescribed by your doctor and never try to adjust your dosage on your own.

The lowest dose of sildenafil (25mg)

Suppose you have health conditions or you are prone to side effects but your doctor has still deemed sildenafil medication appropriate for you. In that case, you are likely to be prescribed the lowest 25mg dosage of sildenafil.

The starting dose of sildenafil (50mg)

If you are taking sildenafil for the first time, the initial starting dose is usually 50mg once all of the eligibility criteria for taking sildenafil have been met. 

If you are experiencing side effects at 50mg or the treatment isn't working, your doctor can still adjust your dosage. 

The highest dose of sildenafil (100mg)

The highest dosage of sildenafil is usually only prescribed after multiple failed attempts at taking the 50mg dosage. 

Sildenafil does not become more effective at dosages higher than 100mg and the effects do not last longer depending on your dosage. 

Sildenafil dosage to treat pulmonary hypertension

If you are using sildenafil to treat pulmonary hypertension there are two strengths available 10mg and 20mg. 

Sildenafil comes in both tablet and liquid form when used to treat pulmonary hypertension. 

1ml of liquid is usually the equivalent of a 10mg tablet but this can differ between medications so always check your label.

Sildenafil for pulmonary hypertension is usually taken 3 times per day for both adults and children.

The lowest dosage (10mg)

10mg of sildenafil, taken 3 times daily, is typically given to children with pulmonary hypertension. 

This can go up to 20mg taken 3 times daily depending on the child's weight.

The highest dosage (20mg)

The higher dosage of 20mg, taken 3 times daily, is typically given to adults with pulmonary hypertension. 

Although this can vary depending on the adult. 

Sildenafil dosage guide: FAQs

Is it okay to take 100mg of sildenafil?

It is only okay to take 100mg of sildenafil if prescribed to you by your doctor. Never try to double your 50mg dosage. 

What happens if I take my sildenafil dosage with food?

Food can slow down the absorption of sildenafil and can take longer for you to feel the effects of the medication. 

How do I know when to change my sildenafil dosage?

Your doctor will know when it’s time to adjust your sildenafil dosage. Signs that your GP will increase your dosage are if your current dosage is not working and you’re experiencing no side effects. 

Signs that your GP may decrease your dosage include experiencing common side effects.

Where can I purchase sildenafil?

You can purchase sildenafil over the counter under the brand name Viagra Connect, or have it dispensed with a GP prescription. 

You can also use an online prescription service to have your NHS prescription delivered straight to your door.

If you would like to explore your options for erectile dysfunction treatment you can request an assessment from one of our online clinicians to see if you are eligible.

Advice and information to help erectile dysfunction