Spedra vs Viagra: Which Is More Effective for Erectile Dysfunction?

Wondering which erectile dysfunction treatment is the right one for you? We spoke to our MedExpress experts to learn more about the differences between two popular brands: Viagra and Spedra.

Let's explore them in more detail, to better understand which one may be most suitable for you.

Article Summary:

• Spedra and Viagra are both medications which are approved for the treatment of erectile dysfunction.
• As PDE5 inhibitors, they both work by increasing blood flow into the penis.
• Speak to your healthcare provider about your options for erectile dysfunction treatment. They can assess whether medication is right for you, and which might be most suitable.

What's Spedra (avanafil) and how does it work?

Spedra is a medication approved for the treatment of erectile dysfunction, which contains the active ingredient avanafil. Spedra works by helping the blood vessels in the penis to relax. This increases the blood flow into your penis, helping you to achieve and maintain an erection. [1] For Spedra to be effective, sexual stimulation is required.

What's Viagra (sildenafil) and how does it work?

Viagra is the brand name for sildenafil. It was the first medication to be approved for the treatment of erectile dysfunction in the UK. [2] Viagra works in a very similar way to Spedra, by increasing blood flow into your penis when you’re sexually excited. [3]

Spedra and Viagra: at a glance

[3] [4]

What's the difference between Spedra and Viagra?

Both of these erectile dysfunction treatments are PDE5 inhibitors, a type of medication that relaxes blood vessels and encourages blood flow to your penis during sexual activity. However, they contain two different ingredients.

Spedra's active ingredient is called avanafil, whereas Viagra’s is sildenafil. Both of these ingredients are available to purchase under their medical names as generic medications (generic sildenafil and generic avanafil.) Viagra and Spedra are simply the branded alternatives, but they work in exactly the same way as the generics. Whether you choose the branded or generic version of a specific drug comes down to personal preference.

Does Spedra work more quickly than Viagra (sildenafil)?

Spedra (avanafil) has a significantly faster onset of action compared to Viagra (sildenafil). Spedra starts to work in around 30 minutes and, for some, it may work in as quickly as 15 minutes. [4] Viagra, on the other hand, needs to be taken around 30-60 minutes before sexual activity. [3] If you take either Spedra or Viagra after a large meal, your medication may take longer to become effective. [3] [4]

Does Spedra last longer than Viagra (Sildenafil)?

Spedra remains effective for 4-5 hours, which is similar to Viagra. This does not mean that your erection will actually last that long, simply that you may be able to achieve an improved erection for that period of time.

It's important to remember that your medication will only work if you’re sexually aroused.

If you experience a prolonged erection of 4 hours or more, it's important that you seek urgent medical attention. This is called 'priapism', and may cause damage to your penis without medical intervention. Call 111 or visit your local emergency department if this happens.

Is Spedra more effective than Viagra?

In a multi-centre clinical trial, approximately two-thirds (66%) of the participants were able to engage in sexual activity within 15 minutes with Spedra. [5] Throughout each trial, all those who took three different strength doses (50mg, 100mg and 200mg) of avanafil achieved statistically significant improvements compared to those who received the placebo (fake treatment).

A separate medical trial has also shown that Viagra is an effective treatment for over 80% of people assigned male at birth (AMAB). [6] It usually takes around 30-60 minutes for Viagra to start working for erectile dysfunction. [3]

But how do the two directly compare? While some data suggests that Spedra may be more effective, more research is required. [7] It ultimately comes down to which erectile dysfunction treatment your prescriber believes is right for you. And their decision will be based on which medication best meets your needs.

How do the side effects of Spedra compare to those of Viagra?

Like any medicine, both Viagra and Spedra may cause adverse side effects. And, because Spedra and Viagra both work in a similar way, they share some similar side effects. However, not everyone will experience them.

Common side effects in both Viagra and Spedra may include headaches, nasal congestion and facial flushing. Uncommon side effects include heart palpitations and visual side effects, like a colour tinge to your vision. [4] [8]

If you experience any of the following side effects when taking Spedra, please seek immediate medical advice:

• An erection that will not go away (priapism). As explained above, if you get an erection that lasts more than 4 hours, this must be treated as soon as possible.
• Blurred vision
• Sudden decrease or loss of vision in one or both eyes
• Sudden decrease or loss of hearing [4]
• Any symptoms typical of an allergic reaction to a drug [9]

If you experience any of the following side effects when taking Viagra, please seek immediate medical advice:

• An allergic reaction (symptoms include sudden wheeziness, difficulty in breathing or dizziness, swelling of the eyelids, face, lips or throat.)
• Chest pains during or after sex
• Priapism
• A sudden decrease or loss of vision
• Serious skin reactions (symptoms may include severe peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes, fever.)
• Seizures [8]

No matter which type of erectile dysfunction treatment you're considering, it's important that you tell your healthcare provider about any pre-existing medical conditions, and any other medications or any herbal remedies or supplements you’re taking. This is because certain types of erectile dysfunction treatment may not mix well with other types of medication. For example, while Spedra and Viagra are generally safe for people with controlled blood pressure, you shouldn’t take these treatments if you're also taking nitrates. This is because the combination may cause a dangerous drop in blood pressure. [4] [3]

Some clinical data suggests that if you take Spedra, you may experience milder side effects than with similar erectile dysfunction treatments. [10] [11] However, it's worth remembering that side effects may vary from person to person. For a full list of side effects for both Viagra and Spedra, please refer to your patient information leaflet or speak to your healthcare provider.

Which is right for me?

Both Spedra and Viagra have been proven to be safe and effective erectile dysfunction treatments, and are trusted by people across the world. Ask your healthcare provider if either Spedra or Viagra are right for you.

Remember to always speak to a clinical expert to discuss your options and any common side effects that could occur from treatment.

Find out what treatment may be suitable for you with MedExpress.

References

1. Spedra 50 mg tablets - Patient Information Leaflet (PIL) - (emc) | 5331 [Internet]. Medicines.org.uk. 2025 [cited 2026 May 15]. Available from: https://www.medicines.org.uk/emc/product/5331/pil
2. Connelly D. Three decades of Viagra [Internet]. The Pharmaceutical Journal. Available from: https://pharmaceutical-journal.com/article/infographics/three-decades-of-viagra
3. NHS. About Sildenafil (Viagra) [Internet]. nhs.uk. 2022. Available from: https://www.nhs.uk/medicines/sildenafil-viagra/about-sildenafil-viagra/
4. Package leaflet: Information for the patient Spedra 50 mg tablets Spedra 100 mg tablets Spedra 200 mg tablets avanafil [Internet]. [cited 2026 May 14]. Available from: https://www.medicines.org.uk/emc/files/pil.5331.pdf
5. Sanford M. Avanafil: A Review of Its Use in Patients with Erectile Dysfunction. Drugs & Aging. 2013 Aug 17;30(10):853–62.
6. Fink HA, Mac Donald R, Rutks IR, Nelson DB, Wilt TJ. Sildenafil for Male Erectile Dysfunction. Archives of Internal Medicine. 2002 Jun 24;162(12):1349.
7. Kumar M, Amey Pathade, Gupta S, Goyal S, Rath D, Manish Thakre, et al. Efficacy and safety of avanafil as compared with sildenafil in the treatment of erectile dysfunction: A randomized, double blind, multicenter clinical trial. International Journal of Urology [Internet]. 2022 Jan 26;29(4):351–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9303470/#
8. Available from: https://www.medicines.org.uk/emc/files/pil.7141.pdf
9. Drug Allergy | Allergy UK | National Charity [Internet]. Allergy UK | National Charity. 2025. Available from: https://www.allergyuk.org/about-allergy/types-of-allergies/drug-allergy/
10. L.I. Smith-Harrison, Patel A, Smith RP. The devil is in the details: an analysis of the subtleties between phosphodiesterase. Translational Andrology and Urology. 2016 Mar 25;5(2):181–6.
11. Katz EG, Tan RB, Rittenberg D, Hellstrom WJ. Avanafil for erectile dysfunction in elderly and younger adults: differential pharmacology and clinical utility. Therapeutics and Clinical Risk Management [Internet]. 2014 Aug 27;10:701–11. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155803/