Plain, Discreet
Packaging
Tracked 24*7
Delivery
Sildenafil Tablets
- Available in 25mg, 50mg, and 100mg strengths
- The most widely used ED treatment in the UK
- Taken on demand, 30–60 minutes before sexual activity
- UK Pharmacy
- GPhC Registered
- Discreet Delivery
Overview
Sildenafil is a prescription-only medicine used to treat erectile dysfunction (ED) in adult men. It is the active ingredient in Viagra and belongs to a group of medicines known as PDE5 inhibitors — the same family as tadalafil (Cialis) and avanafil (Spedra).
Sildenafil is the most widely prescribed ED treatment in the UK. It typically begins working within 30–60 minutes when taken on an empty stomach, and its effects can last for up to 4–6 hours.
It is available in three strengths — 25mg, 50mg, and 100mg — allowing for dose adjustment based on effectiveness and tolerability.
Sildenafil is a prescription-only medicine (POM). It can only be supplied after an online clinical assessment has been reviewed and approved by a prescriber.
AM I SUITABLE FOR SILDENAFIL 50MG?
Sildenafil 50mg may be suitable if you:
- Are aged 18 or over
- Have difficulty getting or maintaining an erection
- Are not taking medicines that interact with sildenafil
It may not be suitable if you:
- Take nitrates for heart conditions
- Have certain heart, liver, or blood pressure conditions
- Have been advised not to have sex for medical reasons
A pharmacist will review your answers before supply.
LEARN MORE ABOUT THIS TREATMENT
How Sildenafil Works
- Blocks the enzyme phosphodiesterase type 5 (PDE5)
- Supports the natural process of arousal by improving blood flow
- Requires sexual stimulation to be effective — it will not cause an erection on its own
How to Take Sildenafil
Strengths available:
25mg, 50mg, 100mg tablets.
Dosage guidance
- The usual starting dose is 50mg, taken approximately 30–60 minutes before sexual activity.
- It can be adjusted to 25mg (if the starting dose is highly effective or side effects occur) or 100mg (if the starting dose provides unsatisfactory results).
- Swallow the tablet whole with water.
- Do not take more than one tablet in any 24-hour period.
- Do not take sildenafil within 24 hours of another ED medication.
- Effects typically begin within 30–60 minutes and last for around 4–6 hours.
- Sexual stimulation is required for the treatment to work.
Food and alcohol
- Sildenafil can be taken with or without food, but it works fastest on an empty stomach.
- A heavy or high-fat meal may delay absorption and reduce effectiveness.
- Alcohol can reduce the ability to achieve an erection and may increase the risk of side effects such as dizziness and low blood pressure.
SAFETY AND SIDE EFFECTS
Sildenafil is generally well tolerated, but like all medicines, side effects can occur.
Common side effects (may affect up to 1 in 10 men)
- Headache
- Flushing (face or skin going red)
- Nasal or sinus congestion
- Indigestion
- Dizziness
- Visual disturbances (such as a blue tinge to vision or increased sensitivity to light)
Seek urgent medical attention if you experience
- An erection lasting longer than 4 hours (priapism) - this requires immediate treatment to prevent lasting damage
- Sudden decrease or loss of vision in one or both eyes
- Sudden decrease or loss of hearing, sometimes with ringing in the ears or dizziness
- Chest pain during or after sexual activity
Who should not take sildenafil
- Sildenafil is not suitable for everyone. You should not take sildenafil if you: Take nitrates (used for angina or heart conditions), this combination can cause a dangerous drop in blood pressure
- Use recreational nitrate drugs (sometimes known as "poppers")
- Have recently had a stroke or heart attack
- Have severe heart or liver problems
- Have low blood pressure or uncontrolled high blood pressure
- Take riociguat for pulmonary hypertension
- Have been advised to avoid sexual activity for medical reasons
Other prescription and non-prescription medicines can interact with sildenafil. These are checked during your clinical assessment.
Patient Information Leaflet
For full usage and safety information, please read the official patient information leaflet provided with the product.
Sildenafil patient information leaflet
How Sildenafil Compares
| Feature | Sildenafil | Tadalafil | Spedra (avanafil) |
| Time to take effect | 30–60 minutes | 30–60 minutes | 15–30 minutes |
| Duration | 4–6 hours | Up to 36 hours | 4–6 hours |
| Food impact | Delayed if taken with food | Minimal effect | Delayed if taken with food |
| Typical use | On demand | On demand or daily | On demand |
Your prescriber can help you decide which option may be most suitable for your needs.
Author Information
All of our medication and condition content is written by UK qualified pharmacists and doctors.
Authored by
Amit Raj
Superintendent Pharmacist
Reviewed by
XXXXXXXXXX
Medical Advisor / Pharmacist or Doctor
GPhC Number: 225377
Review Date:
XX March 2026
Next Review:
XX March 2027
Published on:
XX March 2026
Last Update:
XX March 2026
FREQUENTLY ASKED QUESTIONS
Trust and Regulation
- UK Clinicians
- Regulated Pharmacy
- Discreet Delivery
Overview
Plain, Discreet
Packaging
Tracked 24*7
Delivery
Sildenafil Tablets
- Available in 25mg, 50mg, and 100mg strengths
- The most widely used ED treatment in the UK
- Taken on demand, 30–60 minutes before sexual activity
- UK Pharmacy
- GPhC Registered
- Discreet Delivery
Overview
Sildenafil is a prescription-only medicine used to treat erectile dysfunction (ED) in adult men. It is the active ingredient in Viagra and belongs to a group of medicines known as PDE5 inhibitors — the same family as tadalafil (Cialis) and avanafil (Spedra).
Sildenafil is the most widely prescribed ED treatment in the UK. It typically begins working within 30–60 minutes when taken on an empty stomach, and its effects can last for up to 4–6 hours.
It is available in three strengths — 25mg, 50mg, and 100mg — allowing for dose adjustment based on effectiveness and tolerability.
Sildenafil is a prescription-only medicine (POM). It can only be supplied after an online clinical assessment has been reviewed and approved by a prescriber.
AM I SUITABLE FOR SILDENAFIL 50MG?
Sildenafil 50mg may be suitable if you:
- Are aged 18 or over
- Have difficulty getting or maintaining an erection
- Are not taking medicines that interact with sildenafil
It may not be suitable if you:
- Take nitrates for heart conditions
- Have certain heart, liver, or blood pressure conditions
- Have been advised not to have sex for medical reasons
A pharmacist will review your answers before supply.
LEARN MORE ABOUT THIS TREATMENT
How Sildenafil Works
- Blocks the enzyme phosphodiesterase type 5 (PDE5)
- Supports the natural process of arousal by improving blood flow
- Requires sexual stimulation to be effective — it will not cause an erection on its own
How to Take Sildenafil
Strengths available:
25mg, 50mg, 100mg tablets.
Dosage guidance
- The usual starting dose is 50mg, taken approximately 30–60 minutes before sexual activity.
- It can be adjusted to 25mg (if the starting dose is highly effective or side effects occur) or 100mg (if the starting dose provides unsatisfactory results).
- Swallow the tablet whole with water.
- Do not take more than one tablet in any 24-hour period.
- Do not take sildenafil within 24 hours of another ED medication.
- Effects typically begin within 30–60 minutes and last for around 4–6 hours.
- Sexual stimulation is required for the treatment to work.
Food and alcohol
- Sildenafil can be taken with or without food, but it works fastest on an empty stomach.
- A heavy or high-fat meal may delay absorption and reduce effectiveness.
- Alcohol can reduce the ability to achieve an erection and may increase the risk of side effects such as dizziness and low blood pressure.
SAFETY AND SIDE EFFECTS
Sildenafil is generally well tolerated, but like all medicines, side effects can occur.
Common side effects (may affect up to 1 in 10 men)
- Headache
- Flushing (face or skin going red)
- Nasal or sinus congestion
- Indigestion
- Dizziness
- Visual disturbances (such as a blue tinge to vision or increased sensitivity to light)
Seek urgent medical attention if you experience
- An erection lasting longer than 4 hours (priapism) - this requires immediate treatment to prevent lasting damage
- Sudden decrease or loss of vision in one or both eyes
- Sudden decrease or loss of hearing, sometimes with ringing in the ears or dizziness
- Chest pain during or after sexual activity
Who should not take sildenafil
- Sildenafil is not suitable for everyone. You should not take sildenafil if you: Take nitrates (used for angina or heart conditions), this combination can cause a dangerous drop in blood pressure
- Use recreational nitrate drugs (sometimes known as "poppers")
- Have recently had a stroke or heart attack
- Have severe heart or liver problems
- Have low blood pressure or uncontrolled high blood pressure
- Take riociguat for pulmonary hypertension
- Have been advised to avoid sexual activity for medical reasons
Other prescription and non-prescription medicines can interact with sildenafil. These are checked during your clinical assessment.
Patient Information Leaflet
For full usage and safety information, please read the official patient information leaflet provided with the product.
Sildenafil patient information leaflet
How Sildenafil Compares
| Feature | Sildenafil | Tadalafil | Spedra (avanafil) |
| Time to take effect | 30–60 minutes | 30–60 minutes | 15–30 minutes |
| Duration | 4–6 hours | Up to 36 hours | 4–6 hours |
| Food impact | Delayed if taken with food | Minimal effect | Delayed if taken with food |
| Typical use | On demand | On demand or daily | On demand |
Your prescriber can help you decide which option may be most suitable for your needs.
Author Information
All of our medication and condition content is written by UK qualified pharmacists and doctors.
Authored by
Amit Raj
Superintendent Pharmacist
Reviewed by
XXXXXXXXXX
Medical Advisor / Pharmacist or Doctor
GPhC Number: 225377
Review Date:
XX March 2026
Next Review:
XX March 2027
Published on:
XX March 2026
Last Update:
XX March 2026
FREQUENTLY ASKED QUESTIONS
Trust and Regulation
- UK Clinicians
- Regulated Pharmacy
- Discreet Delivery