Tadalafil and Saxagliptin: Can They Be Taken Together?

Tadalafil and Saxagliptin: Understanding the Interaction

Published: 25 October 2026

Many men wonder whether tadalafil and saxagliptin can be taken together safely. Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction, while saxagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor prescribed for type 2 diabetes. The good news is that no major direct interaction between these two medicines is commonly reported in clinical practice, but your prescriber will still review your full medical history and current medications during an online consultation to ensure the combination is appropriate for you [2][4].

What is tadalafil and how does it work?

Tadalafil is the generic name for Cialis, a prescription medicine licensed in the UK to treat erectile dysfunction (ED) in adult men [4]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing the blood vessels in the penis, allowing more blood to flow in when you are sexually aroused. This helps you get and keep an erection suitable for sexual activity [1][4].

Tadalafil is available in two forms: on-demand tablets (usually 10 mg or 20 mg taken at least 30 minutes before sex, with effects lasting up to 36 hours) and daily low-dose tablets (2.5 mg or 5 mg taken once a day) [4]. Unlike some other ED treatments, tadalafil's long duration of action means you do not need to time it as precisely, which many men find convenient. However, it only works when you are sexually stimulated—it does not cause an automatic erection [1][4].

At Cured Pharmacy, tadalafil is available after a confidential online consultation reviewed by a UK-registered prescriber. Common side effects include headache, indigestion, back pain, muscle aches, flushing, and nasal congestion, which are usually mild and temporary [4].

What is saxagliptin and why is it prescribed?

Saxagliptin is a prescription medicine used to help control blood sugar levels in adults with type 2 diabetes [12]. It is part of a class of drugs called DPP-4 inhibitors (also known as gliptins), which work by increasing the levels of natural substances called incretins. These incretins help the body produce more insulin when blood sugar is high and reduce the amount of sugar made by the liver [12].

Saxagliptin is usually taken once a day, with or without food, and is often prescribed alongside other diabetes medicines such as metformin or a sulfonylurea, or as part of a broader diabetes management plan that includes diet and exercise [12]. Brand names in the UK include Onglyza, and it is also available in combination tablets with metformin (Komboglyze).

Common side effects of saxagliptin include upper respiratory tract infections, urinary tract infections, headache, and occasionally low blood sugar (hypoglycaemia), especially when taken with other diabetes medicines [12]. It is important to continue taking saxagliptin as prescribed and to attend regular diabetes check-ups with your GP or diabetes nurse.

Can tadalafil and saxagliptin be taken together?

Yes, tadalafil and saxagliptin can generally be taken together, as no major direct drug interaction between these two medicines is commonly reported in clinical practice [2][4]. They work through different mechanisms in the body: tadalafil acts on blood vessels in the penis to improve erectile function, while saxagliptin works on the hormones that regulate blood sugar in people with type 2 diabetes. Because their actions do not directly interfere with each other, they are often prescribed together for men who have both erectile dysfunction and type 2 diabetes [1][2].

However, it is essential that your prescriber reviews your full medical history and all current medications during the consultation. Men with diabetes are at higher risk of cardiovascular disease, and ED itself can be an early warning sign of heart or circulation problems [1][2]. Your prescriber will check your blood pressure, heart health, and any other medicines you take (including other diabetes drugs, blood pressure tablets, or cholesterol-lowering medicines) to ensure tadalafil is safe and appropriate for you [2][4].

Never start, stop, or change the dose of any prescribed medicine without consulting your doctor or pharmacist. If you experience any unusual symptoms after taking tadalafil and saxagliptin together—such as dizziness, chest pain, or unexplained changes in blood sugar—contact your GP or pharmacist promptly for advice.

What your prescriber checks

During your online consultation at Cured Pharmacy, the prescriber will ask about your diabetes control, current medications (including insulin, metformin, sulfonylureas, or SGLT2 inhibitors), blood pressure, heart health, and any history of stroke, heart attack, or other cardiovascular conditions [2][4]. They will also check whether you take any medicines that are known to interact dangerously with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or alpha-blockers like tamsulosin or doxazosin [4]. This thorough review ensures that tadalafil is safe for you and that the dose is appropriate given your overall health and medication regimen.

Understanding how tadalafil and saxagliptin interact in the body

Tadalafil is primarily broken down in the liver by an enzyme called CYP3A4, and to a lesser extent by CYP2C9 [4]. Saxagliptin is also metabolised by CYP3A4, but it does not significantly inhibit or induce this enzyme, meaning it is unlikely to alter the levels of tadalafil in your bloodstream in a clinically meaningful way [12]. Similarly, tadalafil does not affect the enzymes that break down saxagliptin, so the blood sugar control provided by saxagliptin should remain stable when tadalafil is added [4][12].

Both medicines can, in theory, have a mild effect on blood pressure. Tadalafil can cause a small, temporary drop in blood pressure (which is usually well tolerated), while saxagliptin itself does not typically lower blood pressure [4][12]. However, many men with type 2 diabetes also take blood pressure medicines (such as ACE inhibitors, angiotensin receptor blockers, or calcium channel blockers), and the combination of tadalafil with these other drugs can add to the blood-pressure-lowering effect, potentially causing dizziness or light-headedness [2][4].

This is why your prescriber will review all your current medicines during the consultation. If you are on multiple medications for diabetes, blood pressure, or cholesterol, the prescriber may start you on a lower dose of tadalafil and advise you to monitor for any dizziness or unusual symptoms, especially when you first start treatment [2][4].

Other diabetes medicines and tadalafil

If you take other diabetes medicines alongside saxagliptin—such as metformin, gliclazide, insulin, or an SGLT2 inhibitor like empagliflozin—these do not usually interact directly with tadalafil either [2][4]. However, your prescriber will still review the full list to check for any indirect effects or contraindications. For example, if you also take an alpha-blocker for prostate symptoms (common in men with diabetes), there is a known risk of low blood pressure when combined with tadalafil, and your prescriber will adjust the dose or timing accordingly [4].

Practical advice for taking tadalafil and saxagliptin safely

If you have been prescribed both tadalafil and saxagliptin, take each medicine exactly as directed by your doctor or prescriber. Saxagliptin is usually taken once a day at the same time each day, with or without food [12]. Tadalafil on-demand tablets (10 mg or 20 mg) should be taken at least 30 minutes before you plan to have sex, and you should not take more than one dose in 24 hours [4]. If you are on daily tadalafil (2.5 mg or 5 mg), take it at the same time every day, regardless of when you plan to be sexually active [4].

Avoid drinking large amounts of alcohol when taking tadalafil, as heavy drinking can make erectile dysfunction worse and increase the risk of dizziness or low blood pressure [1][4]. Grapefruit juice can also raise the levels of tadalafil in your blood, so it is best to avoid it or limit your intake [4]. Continue to follow your diabetes care plan, including healthy eating, regular exercise, and monitoring your blood sugar as advised by your diabetes team [2].

If you develop any new symptoms—such as persistent dizziness, chest pain during sex, an erection lasting more than four hours (priapism), sudden loss of vision or hearing, or unexplained changes in your blood sugar levels—stop taking tadalafil and seek medical advice immediately [4]. Keep all your medicines in their original packaging, out of reach of children, and check the expiry dates regularly.

When to seek further advice about tadalafil and saxagliptin

Always tell your prescriber or pharmacist about every medicine you take, including prescription drugs, over-the-counter medicines, herbal remedies (such as St John's wort), and supplements [2][4]. If your diabetes treatment changes—for example, if your GP adds a new medicine, adjusts your insulin dose, or switches you to a different diabetes tablet—let your prescriber know before your next tadalafil order, as this may affect the safety or suitability of your ED treatment [2][4].

If you experience new or worsening erectile dysfunction, it is important to see your GP for a full assessment. ED can be an early sign of cardiovascular disease or poorly controlled diabetes, and treating the underlying cause may improve your symptoms [1][2]. Your GP can also check your HbA1c (a measure of long-term blood sugar control), blood pressure, cholesterol, and kidney function, and refer you to a specialist if needed [2].

At Cured Pharmacy, our UK-registered prescribers review every consultation individually and can answer questions about your treatment. If you are unsure whether a new medicine or supplement is safe to take with tadalafil and saxagliptin, contact our pharmacy team or your GP for advice before making any changes. Never stop taking a prescribed medicine without professional guidance, as this could affect your diabetes control or overall health [2][12].

Ordering tadalafil from Cured Pharmacy

Tadalafil is a prescription-only medicine in the UK, so you will need to complete a confidential online consultation before your order can be approved [4]. The consultation asks about your medical history, current medications (including saxagliptin and any other diabetes or blood pressure medicines), and general health. A UK-registered prescriber reviews your answers and, if appropriate, approves your prescription. Your medicine is then dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. If you have any questions during the process, our pharmacy team is here to help.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 25 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 25 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 25 October 2026]
4. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 25 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.

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