Avanafil Dosage: 50mg, 100mg & 200mg Explained

Takes less than 2 minutes to complete 100% online

Avanafil Dosage: How Much Should You Take?

Published: 15 October 2026

The standard avanafil dosage for erectile dysfunction is 100mg, taken about 15–30 minutes before sexual activity, with a maximum of one dose in any 24-hour period [6]. Depending on how well it works and whether you experience side effects, your prescriber may adjust the dose to 200mg (the maximum) or reduce it to 50mg [6]. Avanafil is the active ingredient in Spedra and is one of the fastest-acting oral treatments for ED, requiring sexual stimulation to work [11].

What is the recommended avanafil dosage?

The usual starting dose of avanafil is 100mg, taken as needed approximately 15 to 30 minutes before you plan to have sex [6]. This dose is effective for most men and balances efficacy with tolerability. You should take avanafil only when you anticipate sexual activity, and no more than once in any 24-hour period [6].

If the 100mg dose works well but you experience side effects such as headache, flushing or nasal congestion, your prescriber may reduce the dose to 50mg [6]. Conversely, if 100mg does not produce a sufficient response and you tolerate the medicine well, the dose can be increased to the maximum of 200mg [6]. Any dose adjustment should be made by your prescriber after reviewing your response and medical history.

Avanafil is taken on an empty stomach or with food; unlike some other ED medicines, food does not significantly delay its onset of action [11]. Always swallow the tablet whole with water and do not take more than the prescribed dose. If you are unsure which dose is right for you, your prescriber will guide you during the consultation based on your health, other medicines, and how you respond to treatment.

How does avanafil dosage compare to other ED medicines?

Avanafil belongs to the same class of medicines as sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra)—all are PDE5 inhibitors that help improve blood flow to the penis during sexual arousal [1][6]. What sets avanafil apart is its rapid onset: it can start working in as little as 15 minutes, whereas sildenafil typically takes about an hour, vardenafil 25–60 minutes, and tadalafil at least 30 minutes [3][4][5][6].

In terms of dosing, sildenafil is available in 25mg, 50mg and 100mg strengths, tadalafil in 2.5mg, 5mg, 10mg and 20mg (with daily and on-demand options), and vardenafil in 5mg, 10mg and 20mg [3][4][5]. Avanafil's range of 50mg, 100mg and 200mg offers flexibility similar to sildenafil and vardenafil, but with the advantage of faster action [6][11]. Tadalafil stands out for its long duration—up to 36 hours—while avanafil's effect lasts around 4–6 hours, similar to sildenafil and vardenafil [4][6].

Choosing between these medicines depends on your lifestyle, how quickly you want the medicine to work, how long you want the effect to last, and any other health conditions or medicines you take. Your prescriber will help you decide which PDE5 inhibitor and dose are most suitable for you during the online consultation.

Why avanafil may be preferred

Some men prefer avanafil because of its fast onset, which allows for more spontaneity—you do not need to plan as far ahead as with sildenafil or tadalafil [11]. Clinical trials have shown that avanafil is effective and well tolerated, with a side-effect profile similar to other PDE5 inhibitors [11]. If you have tried other ED medicines and found the timing inconvenient, or if you want a treatment that works quickly without lasting as long as tadalafil, avanafil may be a good option to discuss with your prescriber.

Can you adjust your avanafil dosage?

Yes, avanafil dosage can be adjusted, but only under the guidance of a prescriber [6]. If you start on 100mg and find it effective with minimal side effects, you may continue on that dose. If you experience bothersome side effects—such as headache, facial flushing, back pain or nasal congestion—your prescriber may lower the dose to 50mg to improve tolerability while still providing benefit [6].

On the other hand, if 100mg does not give you the desired improvement in your erections and you tolerate the medicine well, your prescriber may increase the dose to 200mg, which is the maximum licensed dose [6]. It is important never to increase the dose yourself or take more than one tablet in 24 hours, as this raises the risk of side effects and does not improve efficacy [6].

Dose adjustments may also be necessary if you start taking other medicines that interact with avanafil. For example, potent CYP3A4 inhibitors (such as ritonavir, ketoconazole or clarithromycin) can increase avanafil levels in your blood, and avanafil is contraindicated or should be avoided with these medicines [6]. Always tell your prescriber about all medicines you take, including over-the-counter products and herbal supplements, so they can prescribe the safest and most effective dose for you.

What factors affect the right avanafil dosage for you?

Several factors influence which avanafil dosage is most appropriate. Age, overall health, the severity of your erectile dysfunction, and other medical conditions all play a role [2][6]. For example, men with mild ED may respond well to the 50mg dose, while those with more severe ED may need 100mg or 200mg [6]. Your prescriber will assess these factors during the consultation.

Other medicines you take are critical. Avanafil is metabolised by the liver enzyme CYP3A4, so medicines that inhibit this enzyme can raise avanafil levels, increasing the risk of side effects [6]. Potent CYP3A4 inhibitors (such as HIV protease inhibitors, certain antifungals and some antibiotics) mean avanafil should be avoided or used with extreme caution [6]. Conversely, CYP3A4 inducers like rifampicin or St John's wort can reduce avanafil's effectiveness [6].

If you take alpha-blockers for an enlarged prostate or high blood pressure (such as tamsulosin or doxazosin), there is a risk of low blood pressure when combined with avanafil [6]. You should be stable on the alpha-blocker before starting avanafil, and your prescriber will choose the lowest effective dose and monitor you closely. Lifestyle factors such as alcohol intake and grapefruit juice can also affect how avanafil works: heavy drinking can worsen ED and add to blood-pressure-lowering effects, while grapefruit juice can raise avanafil levels [6].

Medical conditions and avanafil dosage

Certain health conditions require careful consideration. Avanafil is not suitable if you have severe heart or liver problems, very low blood pressure, a recent heart attack or stroke, or a history of non-arteritic anterior ischaemic optic neuropathy (sudden vision loss) [6]. Moderate liver or kidney impairment may not require dose adjustment, but your prescriber will review your medical history and may start you on a lower dose if appropriate [6]. Always be honest about your health during the consultation so your prescriber can tailor the treatment safely.

How should you take avanafil for best results?

Take your prescribed avanafil dose about 15 to 30 minutes before you plan to have sex [6]. Swallow the tablet whole with a glass of water; you can take it with or without food, as meals do not significantly affect how quickly avanafil works [11]. Avoid taking avanafil with large amounts of alcohol, as this can make it harder to get an erection and increase the risk of dizziness or low blood pressure [6].

Avanafil only works when you are sexually aroused—it does not cause an automatic erection [6]. If the first dose does not work as well as you hoped, do not take another tablet on the same day. Instead, try again on a different occasion, as it can take a few attempts to find the right timing and level of stimulation. If avanafil consistently does not work for you, speak to your prescriber about adjusting the dose or trying a different ED treatment.

Never take more than one avanafil tablet in 24 hours, and do not combine it with any other PDE5 inhibitor (such as sildenafil, tadalafil or vardenafil) or with nitrate medicines, nicorandil, riociguat or recreational drugs called poppers [6]. These combinations can cause a dangerous drop in blood pressure. If you experience chest pain during sex, do not use nitrate medicines; seek urgent medical help and tell the healthcare professional you have taken avanafil [6].

What are the side effects of different avanafil dosages?

Common side effects of avanafil include headache, flushing (redness and warmth in the face or chest), nasal congestion, and back pain [6][11]. These effects are usually mild to moderate and tend to be dose-related, meaning they may be more noticeable at higher doses such as 200mg [6]. If you experience troublesome side effects on 100mg or 200mg, your prescriber may reduce the dose to 50mg to improve tolerability.

Less common side effects include dizziness, indigestion, nausea, and changes in vision such as blurred vision or increased sensitivity to light [6]. Rarely, avanafil can cause more serious effects: priapism (a painful erection lasting more than four hours), sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing [6]. If any of these occur, stop taking avanafil and seek urgent medical attention.

The risk of side effects is higher if you take avanafil with certain other medicines (such as alpha-blockers or CYP3A4 inhibitors) or if you have underlying health conditions [6]. During your consultation, your prescriber will review your medical history and current medicines to minimise risks. If you experience any new or worsening symptoms after starting avanafil, contact your prescriber or pharmacist for advice. Most men tolerate avanafil well, and side effects often lessen with continued use or dose adjustment [11].

When to seek urgent help

Seek immediate medical help if you have an erection that lasts more than four hours (priapism), as this can cause permanent damage to the penis if not treated promptly [6]. Also seek urgent care if you experience sudden loss of vision or hearing, severe dizziness, fainting, or chest pain during or after sex [6]. If chest pain occurs, do not take nitrate medicines (such as GTN spray); tell the healthcare professional you have taken avanafil so they can treat you safely.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 15 October 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 15 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 15 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 15 October 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 15 October 2026]
6. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 15 October 2026]
7. National Institute for Health and Care Excellence. (2014). Erectile dysfunction: avanafil (ESNM45). https://www.nice.org.uk/advice/esnm45 [accessed 15 October 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.

Get Discreet ED Treatment Online

Start your journey to better health today.

• Reviewed by UK-based prescribers
• Takes under 3 minutes
• Discreet Packaging