Tadalafil and Omeprazole: Can You Take Them Together?

Tadalafil and Omeprazole: Understanding the Interaction

Published: 24 October 2026

Many men taking tadalafil and omeprazole together wonder whether the combination is safe. The good news is that omeprazole, a proton pump inhibitor (PPI) used to reduce stomach acid, is not known to cause a major interaction with tadalafil, a PDE5 inhibitor used to treat erectile dysfunction. However, your prescriber will still review all your current medicines during your consultation to ensure tadalafil is suitable for you overall.

What is tadalafil and omeprazole used for?

Tadalafil is a prescription medicine licensed in the UK to treat erectile dysfunction (ED) and, at lower doses, benign prostatic hyperplasia (BPH) [4]. 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. Tadalafil is available as on-demand tablets (10 mg or 20 mg, taken at least 30 minutes before sex, with effects lasting up to 36 hours) or as a daily low-dose option (2.5 mg or 5 mg) [4].

Omeprazole is a proton pump inhibitor (PPI) commonly prescribed to reduce stomach acid production. It is used to treat conditions such as gastro-oesophageal reflux disease (GORD), stomach ulcers, and indigestion. Omeprazole works by blocking the enzyme in the stomach wall that produces acid, providing relief from heartburn and protecting the stomach lining. Many people take omeprazole long-term for chronic acid-related conditions.

Both medicines are widely prescribed in the UK, and it is not uncommon for men to be taking omeprazole for digestive issues while also seeking treatment for erectile dysfunction. Understanding how these medicines interact—or in this case, do not significantly interact—helps ensure safe and effective treatment.

Do tadalafil and omeprazole interact with each other?

There is no major or clinically significant interaction reported between tadalafil and omeprazole [4][12]. Omeprazole does not affect the way tadalafil is broken down in the body, and tadalafil does not interfere with the acid-reducing action of omeprazole. This means that, in general, the two medicines can be taken together without one reducing the effectiveness of the other or causing a dangerous side effect.

Tadalafil is primarily metabolised by an enzyme in the liver called CYP3A4. Omeprazole is metabolised by different enzymes (mainly CYP2C19 and CYP3A4 to a lesser extent) and is not considered a potent inhibitor or inducer of CYP3A4 at usual doses. As a result, omeprazole does not significantly raise or lower tadalafil levels in the bloodstream, and dose adjustments are not usually needed.

That said, every person's medical history is unique. Your prescriber will review all your current medicines, including omeprazole, during your online consultation to check for any other factors that might affect the safety or suitability of tadalafil. It is important to declare every medicine you take, including over-the-counter products and supplements, so that your prescriber can make an informed decision.

How tadalafil is metabolised in the body

Tadalafil is broken down mainly by the liver enzyme CYP3A4 [4]. Medicines that strongly inhibit this enzyme—such as ritonavir, cobicistat, ketoconazole, itraconazole, and clarithromycin—can increase tadalafil levels in the blood, requiring dose reductions or avoidance. Conversely, medicines that induce CYP3A4, such as rifampicin, carbamazepine, phenytoin, and St John's wort, can lower tadalafil levels and reduce its effectiveness. Omeprazole does not fall into either of these categories, which is why it does not pose a significant interaction risk with tadalafil.

What your prescriber checks before prescribing tadalafil

Before tadalafil is prescribed, a UK-registered prescriber will carry out a thorough clinical assessment. This includes reviewing your medical history, current medicines (including omeprazole and any other PPIs), cardiovascular health, blood pressure, and any conditions that might make tadalafil unsuitable [2][4]. The prescriber will check that you are not taking any medicines that are contraindicated with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites).

If you take medicines for high blood pressure or an enlarged prostate (such as alpha-blockers like doxazosin or tamsulosin), the prescriber will ensure you are stable on that treatment and may recommend starting tadalafil at a lower dose to minimise the risk of dizziness or low blood pressure [4]. The prescriber will also ask about any history of heart problems, stroke, severe liver or kidney disease, or eye conditions such as non-arteritic anterior ischaemic optic neuropathy (NAION), as these can affect whether tadalafil is safe for you.

Declaring omeprazole during your consultation is important, even though it does not interact significantly with tadalafil. The prescriber needs a complete picture of your health and medicines to provide safe, personalised advice. Never stop or change a prescribed medicine without consulting your GP or pharmacist first.

Practical advice for taking tadalafil and omeprazole together

If your prescriber has approved tadalafil for you and you are already taking omeprazole, you can generally take both medicines as directed without concern about a major interaction. Omeprazole is usually taken once daily in the morning, on an empty stomach, about 30 minutes before food. Tadalafil on-demand tablets (10 mg or 20 mg) are taken at least 30 minutes before sexual activity, and the effect can last up to 36 hours [4]. Daily tadalafil (2.5 mg or 5 mg) is taken at the same time each day, regardless of when you plan to have sex.

There is no need to separate the timing of tadalafil and omeprazole, as they do not interfere with each other's absorption or action. However, it is sensible to take each medicine as prescribed: omeprazole works best when taken consistently at the same time each day, and tadalafil requires sexual stimulation to work—it will not cause an erection on its own.

Avoid drinking large amounts of alcohol when taking tadalafil, as heavy drinking can worsen erectile dysfunction and increase the risk of side effects such as dizziness, headache, and low blood pressure. Grapefruit juice can raise tadalafil levels in the blood and should be avoided or limited. If you experience side effects such as severe headache, dizziness, flushing, or indigestion, speak to your pharmacist or GP. Do not take more tadalafil than prescribed, and never combine it with another PDE5 inhibitor or any of the contraindicated medicines listed earlier.

What to do if you start a new medicine

If your GP or another healthcare professional prescribes a new medicine while you are taking tadalafil and omeprazole, always tell them you are using tadalafil for erectile dysfunction. Some medicines—particularly those for heart conditions, high blood pressure, or fungal or HIV infections—can interact with tadalafil. Your prescriber may need to adjust your tadalafil dose or choose an alternative treatment. Similarly, if you buy any over-the-counter medicines, herbal remedies, or supplements, check with your pharmacist first to ensure they are safe to use alongside tadalafil.

Other medicines that can interact with tadalafil

While tadalafil and omeprazole do not interact significantly, tadalafil does have important interactions with other medicines that you must be aware of. Never take tadalafil with nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs called 'poppers' (amyl or alkyl nitrites). Combining tadalafil with any of these can cause a dangerous drop in blood pressure that may be life-threatening [4].

Alpha-blockers used for high blood pressure or an enlarged prostate (such as doxazosin, tamsulosin, alfuzosin, terazosin, prazosin, silodosin, or indoramin) can also lower blood pressure when taken with tadalafil, leading to dizziness or fainting. If you take an alpha-blocker, your prescriber will ensure you are stable on that medicine and will usually start you on the lowest dose of tadalafil [4]. Other blood pressure medicines can add to the blood-pressure-lowering effect of tadalafil, but this is usually manageable and will be checked during your consultation.

Potent CYP3A4 inhibitors—including ritonavir, cobicistat (found in some HIV medicines and in Paxlovid, a COVID-19 treatment), ketoconazole, itraconazole, and clarithromycin—can significantly raise tadalafil levels in the blood. If you take any of these, your prescriber will reduce the maximum dose of tadalafil or advise against using it [4]. Conversely, CYP3A4 inducers such as rifampicin, carbamazepine, phenytoin, and St John's wort can make tadalafil less effective. Always declare every medicine and supplement you take during your consultation.

When to seek urgent medical help

Tadalafil is generally well tolerated, but like all medicines, it can cause side effects in some people. Most side effects are mild and short-lived, such as headache, flushing, indigestion, nasal congestion, or back pain [4]. However, there are a few rare but serious side effects that require urgent medical attention. If you experience an erection that lasts longer than four hours (priapism), seek immediate help by calling 999 or going to A&E. Priapism can damage the penis permanently if not treated promptly.

Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (which may be accompanied by ringing in the ears or dizziness), are also medical emergencies. Stop taking tadalafil and seek urgent medical help if either occurs [4]. If you develop chest pain during or after sexual activity, do not use nitrates to relieve it—tell the healthcare professional that you have taken tadalafil, as nitrates are contraindicated. Seek urgent medical advice if you experience severe dizziness, fainting, or an allergic reaction (such as swelling of the face, lips, tongue, or throat, or difficulty breathing).

If you have new or worsening erectile dysfunction, it is important to see your GP for a full assessment. ED can be an early warning sign of underlying health conditions such as heart disease, diabetes, or high blood pressure [1][2]. Your GP can investigate the cause, optimise treatment for any underlying conditions, and refer you to a specialist if needed. Cured Pharmacy's online consultation is designed to provide convenient access to ED treatment, but it does not replace a face-to-face assessment by your GP, especially if ED is a new symptom.

How Cured Pharmacy can help

Cured Pharmacy is a GPhC-registered online pharmacy (GPhC 9012511) offering discreet, convenient access to a range of ED treatments, including tadalafil. Every order requires completion of an online consultation, which is reviewed by a UK-registered prescriber. If tadalafil is suitable for you, your medicine will be dispensed by our pharmacy team and delivered discreetly to your door. We offer both branded and generic options at transparent prices, and first-time customers can save 20% with code Ednew. Our team is here to answer any questions about your treatment, including interactions with other medicines such as omeprazole.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 24 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 24 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 24 October 2026]
4. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 24 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.