Sildenafil and Simvastatin: Can You Take Them Together?

Sildenafil and Simvastatin: Understanding the Interaction

Published: 16 October 2026

Many men taking simvastatin for high cholesterol wonder whether sildenafil and simvastatin can be taken together safely. The good news is that sildenafil (the active ingredient in Viagra) can usually be used alongside simvastatin, but there is a small interaction that your prescriber will consider. This page explains what each medicine does, how they may interact, what checks are needed, and practical advice for using ED treatment when you're on a statin.

What is sildenafil and simvastatin used for?

Sildenafil is a medicine used to treat erectile dysfunction (ED) in men. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused [3]. Sildenafil is the generic name for Viagra and is available in 25 mg, 50 mg and 100 mg tablets. You take it about one hour before sexual activity, and it can help you get and keep an erection sufficient for sex. Sildenafil does not work without sexual stimulation and should not be taken more than once a day [1].

Simvastatin is a statin medicine used to lower cholesterol levels in the blood. High cholesterol is a risk factor for heart disease and stroke, so simvastatin helps reduce your risk of cardiovascular problems [12]. It works by blocking an enzyme in the liver that makes cholesterol. Many men take simvastatin long-term as part of their heart-health plan. Interestingly, the same cardiovascular risk factors that make statins necessary—such as high cholesterol, diabetes and high blood pressure—are also common causes of erectile dysfunction [10]. This means it is not unusual for men to need both a statin and an ED treatment at the same time.

Is there an interaction between sildenafil and simvastatin?

Yes, there is a recognised interaction between sildenafil and simvastatin, but it is generally considered minor and manageable [3][12]. Simvastatin is broken down in the body by an enzyme system called CYP3A4. Sildenafil is also partly processed by the same enzyme system. When taken together, sildenafil may slightly increase the level of simvastatin in your blood, which could in theory raise the risk of statin-related side effects such as muscle aches or, very rarely, muscle damage.

However, this interaction is not strong enough to mean you cannot take the two medicines together. The increase in simvastatin levels is usually small, and most men tolerate the combination without any problems. Your prescriber will take your simvastatin dose into account when deciding whether sildenafil is suitable for you and may start you on a lower dose of sildenafil if needed. It is important to mention all your current medicines, including simvastatin, during your online consultation so that the prescriber can assess the interaction and advise you safely [2].

How the interaction works (in plain English)

Both sildenafil and simvastatin are processed by the same enzyme in your liver (CYP3A4). When you take them together, they compete for that enzyme's attention. This can slow down the breakdown of simvastatin slightly, meaning a bit more of it stays in your bloodstream for a little longer. The effect is usually mild, but it is why your prescriber needs to know about your statin when prescribing sildenafil. If you are on a high dose of simvastatin (for example, 80 mg daily), your prescriber will be especially careful and may choose a lower starting dose of sildenafil or consider an alternative ED treatment [3][12].

What does your prescriber check before prescribing sildenafil with simvastatin?

When you request sildenafil through an online consultation at Cured Pharmacy, a UK-registered prescriber will review your medical history and current medicines before approving your treatment. If you are taking simvastatin, the prescriber will check the dose you are on and whether you have had any side effects from it, such as muscle pain or weakness. They will also review your overall cardiovascular health, because both high cholesterol and erectile dysfunction can be linked to heart disease [1][2].

The prescriber will ensure that sildenafil is safe for you by checking that you are not taking any medicines that are contraindicated with PDE5 inhibitors, such as nitrates (GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or recreational drugs known as poppers. These combinations can cause a dangerous drop in blood pressure and must be avoided [3]. If you are on other blood-pressure medicines or alpha-blockers (such as tamsulosin for prostate symptoms), the prescriber will also take these into account, as they can add to the blood-pressure-lowering effect of sildenafil.

If the prescriber decides that sildenafil is suitable for you, they may start you on the standard dose (usually 50 mg) or a lower dose (25 mg) depending on your simvastatin dose and other factors. You should always tell the prescriber about every medicine you take, including over-the-counter products and supplements, to ensure a safe and effective treatment plan [2].

Practical advice for taking sildenafil and simvastatin together

If your prescriber approves sildenafil for you while you are on simvastatin, there are some practical steps you can take to use both medicines safely. First, continue taking your simvastatin exactly as your doctor has prescribed—do not stop or change the dose without medical advice. Simvastatin is usually taken once daily in the evening, and you should keep to that routine [12]. Sildenafil is taken only when you plan to have sex, about one hour beforehand, so the two medicines are unlikely to be taken at exactly the same time of day.

Watch out for any unusual muscle pain, tenderness or weakness, especially if it is unexplained or accompanied by feeling generally unwell or feverish. These can be signs of a rare but serious side effect of statins called rhabdomyolysis (muscle breakdown). Although the risk is very low, the interaction with sildenafil could slightly increase statin levels, so it is important to be aware of this warning sign and contact your GP promptly if it occurs [12]. Most men experience no problems at all, but it is sensible to be informed.

Avoid drinking large amounts of alcohol when using sildenafil, as heavy drinking can make erectile dysfunction worse and add to the blood-pressure-lowering effect of the medicine, increasing the chance of dizziness or fainting [3]. Grapefruit juice can also raise the levels of both simvastatin and sildenafil in your blood, so it is best to avoid it or limit your intake while on these medicines. If you experience any side effects from either medicine, or if your ED treatment is not working as well as expected, speak to your prescriber or pharmacist for advice. Do not take more sildenafil than prescribed, and remember that it should not be used more than once in 24 hours [1][3].

What if I'm on a different statin?

If you take a different statin such as atorvastatin, rosuvastatin, pravastatin or fluvastatin, similar considerations apply. Atorvastatin is also processed by CYP3A4 and has a comparable interaction with sildenafil to simvastatin. Rosuvastatin, pravastatin and fluvastatin are less affected by this enzyme, so the interaction is even smaller. Your prescriber will review whichever statin you are on during your consultation and adjust your ED treatment accordingly. Always declare your current medicines so that the prescriber can make an informed decision about your safety [2][3].

Are there alternative ED treatments if I'm concerned about the interaction?

If you are worried about taking sildenafil with simvastatin, or if your prescriber feels that an alternative would be more suitable, there are other PDE5 inhibitors available. Tadalafil (the generic form of Cialis) is another popular option that works in a similar way to sildenafil but lasts much longer—up to 36 hours—so you do not need to time it as precisely before sex [4]. Tadalafil also interacts with simvastatin via the same enzyme pathway, but the interaction is managed in the same way by your prescriber.

Vardenafil (generic Levitra) and avanafil (Spedra) are two other PDE5 inhibitors licensed in the UK for erectile dysfunction [5][6]. Vardenafil works within 25 to 60 minutes and avanafil can work in as little as 15 to 30 minutes. Both have similar interactions with statins, and your prescriber will consider your full medication list when recommending the most appropriate treatment. All PDE5 inhibitors require sexual stimulation to work and should not be taken with nitrates, nicorandil, riociguat or poppers [3][4][5][6].

At Cured Pharmacy, we offer a range of ED treatments at transparent prices. After completing an online consultation reviewed by a UK prescriber, you can choose from sildenafil, tadalafil, vardenafil or avanafil, depending on what is clinically suitable for you. Every prescription medicine is dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. If you have any questions about which treatment is right for you while taking simvastatin, our pharmacists are here to help.

When to seek medical advice about sildenafil and simvastatin

Most men can safely use sildenafil alongside simvastatin with no problems, but there are some situations where you should seek medical advice. If you develop unexplained muscle pain, tenderness, weakness or cramps, especially if you also feel unwell or feverish, contact your GP the same day or call NHS 111. These symptoms could indicate a rare side effect of statins that requires urgent assessment [12]. If you experience chest pain during or after sex, stop the activity and seek medical help immediately—do not take another dose of sildenafil until you have been assessed by a doctor [1][3].

You should also seek urgent help if you have an erection that lasts longer than four hours (priapism), sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing. These are rare but serious side effects of PDE5 inhibitors that need immediate medical attention [3]. If you feel dizzy, lightheaded or faint after taking sildenafil, sit or lie down until the feeling passes, and let your prescriber know at your next review. This can be a sign that your blood pressure has dropped too much, which may be more likely if you are on other blood-pressure medicines as well as simvastatin.

If your erectile dysfunction is new or has recently got worse, it is important to see your GP for a full assessment. ED can be an early warning sign of cardiovascular disease or diabetes, and your doctor may want to check your heart health, blood pressure, blood sugar and cholesterol levels [1][2]. Treating the underlying cause, as well as the ED itself, can improve your overall health and quality of life. Never stop taking simvastatin or any other prescribed medicine without speaking to your doctor first, even if you think it might be affecting your erections—there are usually ways to manage both conditions together safely.

What about other medicines I'm taking?

If you take other medicines alongside simvastatin and sildenafil, it is essential to declare them all during your online consultation. Alpha-blockers (such as tamsulosin, doxazosin or alfuzosin) used for prostate symptoms can interact with sildenafil and increase the risk of low blood pressure and dizziness. Your prescriber will check that you are stable on the alpha-blocker and may start you on a lower dose of sildenafil [3]. Other blood-pressure medicines can also add to the blood-pressure-lowering effect, so your prescriber needs to know about them. Some antibiotics and antifungal medicines (such as clarithromycin, erythromycin, ketoconazole and itraconazole) can raise sildenafil levels significantly, so your dose may need to be adjusted or an alternative treatment considered [3][12]. Always be honest and thorough when listing your medicines—it helps keep you safe.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 16 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 16 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 16 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 16 October 2026]
5. Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994). Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study. Journal of Urology, 151(1), 54–61. https://pubmed.ncbi.nlm.nih.gov/8254833/ [accessed 16 October 2026]
6. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 16 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.