Understanding Sildenafil's Mechanism of Action
What Is Sildenafil and How Does It Work?
Sildenafil belongs to a class of medications called phosphodiesterase type 5 (PDE5) inhibitors, as detailed in the BNF. When you become sexually aroused, your body naturally releases nitric oxide in the penis. This chemical triggers the production of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscles in blood vessels and allows increased blood flow to the penis.
The PDE5 enzyme typically breaks down cGMP, reducing blood flow. Sildenafil works by blocking this PDE5 enzyme, allowing cGMP levels to remain elevated and maintaining improved blood flow during sexual arousal. This mechanism helps men achieve and maintain erections suitable for sexual activity.
Timeline: When Sildenafil Starts Working
Most men find sildenafil becomes effective within 30-60 minutes of taking the tablet. The medication reaches peak blood levels approximately 60 minutes after oral administration. However, individual response times can vary based on factors such as age, metabolism, food intake, and overall health status.
Taking sildenafil on an empty stomach may result in faster absorption, whilst fatty meals can delay the onset of action by up to an hour. The effects typically last between 4-6 hours, though this doesn't mean you'll have an erection for this entire period - sexual stimulation is still required throughout.
Dosage Information According to BNF Guidelines
The BNF recommends starting with sildenafil 50mg, taken approximately one hour before sexual activity. Based on effectiveness and tolerability, your prescriber may adjust this to 25mg or increase to 100mg. The maximum recommended dose is 100mg, and you should never take more than one dose in a 24-hour period.
EverydayMeds offers both branded Viagra and generic sildenafil in all standard strengths (25mg, 50mg, and 100mg). Both formulations contain the same active ingredient and work identically - the choice between branded and generic often comes down to personal preference and cost considerations.
Important Considerations for Safe Use
Sildenafil requires sexual arousal to work effectively - it won't cause automatic erections. The medication enhances your body's natural response to sexual stimulation rather than replacing it. This is an important distinction that helps ensure the medication works as intended.
Before starting sildenafil treatment, you'll need to complete a clinical assessment with a UK-licensed prescriber. This evaluation ensures the medication is suitable for your individual health profile and doesn't interact with other medications you may be taking.
Who Can Use Sildenafil?
Sildenafil is suitable for adult men experiencing erectile dysfunction. However, it's not appropriate for everyone. Men taking nitrate medications (such as GTN spray), those with severe heart conditions, or individuals with certain other health conditions may not be suitable candidates for sildenafil treatment.
Your online consultation will assess your medical history, current medications, and overall cardiovascular health to determine if sildenafil is safe and appropriate for you. This thorough assessment process helps ensure you receive treatment that's both effective and safe.
