Tadalafil and Denosumab: Can You Take Them Together?

Takes less than 2 minutes to complete 100% online

At a glance

What Is Tadalafil and How Does It Work?

Tadalafil is a prescription medicine used to treat erectile dysfunction (ED) in men [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 [1]. Unlike some other ED treatments, tadalafil can remain effective for up to 36 hours, which is why it is sometimes called the 'weekend pill' [4].

Tadalafil is available in two forms: on-demand tablets (usually 10mg or 20mg taken at least 30 minutes before sexual activity) and daily low-dose tablets (2.5mg or 5mg taken once a day) [4]. Both generic tadalafil and the branded version Cialis are available. Sexual stimulation is still needed for the medicine to work [1]. Common side effects include headache, indigestion, back pain, and facial flushing, which are usually mild and temporary [4].

What Is Denosumab and Why Is It Prescribed?

Denosumab is a prescription medicine used to treat osteoporosis (thinning of the bones) and to prevent bone fractures in people at high risk [12]. It is also used to prevent bone complications in patients with certain cancers that have spread to the bones. Denosumab is given as an injection under the skin, usually once every six months for osteoporosis (brand name Prolia) or once every four weeks for cancer-related bone disease (brand name Xgeva) [12].

Denosumab works by blocking a protein called RANKL, which is involved in breaking down bone tissue. By inhibiting this protein, denosumab helps to strengthen bones and reduce the risk of fractures [12]. It does not affect blood pressure, blood flow, or the enzymes that break down tadalafil in the body. Common side effects of denosumab include joint or muscle pain, skin reactions at the injection site, and a small risk of low calcium levels in the blood [12].

How Denosumab Differs from Other Bone Medicines

Unlike bisphosphonates (such as alendronic acid or risedronate), which are taken orally and can sometimes cause stomach irritation, denosumab is given by injection and works through a different mechanism [12]. This means it does not share the same drug-interaction profile as oral bone medicines. Denosumab is not metabolised by the liver enzymes (such as CYP3A4) that process tadalafil, so there is no pharmacokinetic interaction between the two [4][12].

Tadalafil and Denosumab: Is There an Interaction?

No significant interaction between tadalafil and denosumab is commonly reported in clinical practice or listed in the British National Formulary [4][12]. The two medicines work through completely different pathways in the body: tadalafil affects blood vessel relaxation and erectile function, while denosumab targets bone metabolism. Neither medicine is known to alter the effectiveness or safety of the other when taken together.

However, it is still essential to tell your prescriber about all the medicines you are taking, including denosumab, when you request tadalafil [2]. This allows the prescriber to review your full medical history and check for any other conditions or medicines that might affect the safety of tadalafil. For example, if you are taking medicines for high blood pressure or heart disease alongside denosumab, those medicines may require additional checks before starting tadalafil [3][4].

Why You Should Still Declare All Your Medicines

Even though tadalafil and denosumab do not interact directly, your overall health picture matters. Men with osteoporosis may also have other conditions such as cardiovascular disease, diabetes, or high blood pressure, which can influence whether tadalafil is suitable and at what dose [2]. During your online consultation at Cured Pharmacy, the prescriber will review every medicine you are taking to ensure tadalafil is safe and appropriate for you. Never stop or change a prescribed medicine without advice from your doctor or pharmacist.

What you need to know

• No major interaction between tadalafil and denosumab is commonly reported in clinical practice
• The two medicines work through different pathways and do not interfere with each other
• Always declare all medicines during your consultation so the prescriber can review your full history
• Continue your denosumab injections as scheduled; no special timing needed with tadalafil
• Seek urgent help for erection lasting over 4 hours, sudden vision loss, or chest pain during sex

What Your Prescriber Checks Before Approving Tadalafil

When you complete an online consultation for tadalafil, the prescriber will ask about your current medicines, medical history, and any symptoms you are experiencing [2]. They will check whether you are taking any medicines that are known to interact dangerously with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called 'poppers' [3][4]. These combinations can cause a dangerous drop in blood pressure and must never be used together.

The prescriber will also review whether you take alpha-blockers (such as tamsulosin or doxazosin) for prostate symptoms, as these can add to the blood-pressure-lowering effect of tadalafil and may require a lower starting dose [4]. If you are on medicines that affect how the liver processes tadalafil—such as certain antifungals, antibiotics, or HIV treatments—the prescriber may adjust your dose or recommend an alternative [4][12]. Denosumab itself does not fall into any of these categories, so it does not usually require a dose adjustment of tadalafil.

Practical Advice for Taking Tadalafil with Denosumab

If you are already receiving denosumab injections and your prescriber approves tadalafil, you can take them together without special timing considerations. Denosumab is given every few months, while tadalafil is taken either daily or on-demand before sexual activity [4][12]. There is no need to avoid tadalafil on the day of your denosumab injection or vice versa, as the two medicines do not interfere with each other's absorption or action.

Continue to attend your regular appointments for denosumab injections and any blood tests your doctor has requested (for example, to monitor calcium levels) [12]. If you experience new symptoms after starting tadalafil—such as dizziness, chest pain during sex, or an erection lasting more than four hours—seek medical help promptly and inform your healthcare team that you are taking both medicines [1][4]. Keep a list of all your medicines, including over-the-counter products and supplements, and share it with every healthcare professional you see.

Lifestyle Factors That Support Both Bone and Sexual Health

Maintaining a healthy lifestyle can benefit both your bone health and erectile function. Regular weight-bearing exercise, a balanced diet rich in calcium and vitamin D, and avoiding smoking can help strengthen bones and improve cardiovascular health [1][2]. Limiting alcohol intake is also important, as heavy drinking can worsen erectile dysfunction and may interfere with bone health. If you have concerns about either condition, speak to your GP, who can offer tailored advice and refer you to a specialist if needed.

When to get urgent help

• Erection lasting more than 4 hours (priapism) – call 999 or go to A&E immediately
• Sudden loss of vision or hearing – seek urgent medical attention
• Chest pain during sexual activity – stop and call 999; do not take more tadalafil
• Severe dizziness or fainting after taking tadalafil – seek same-day medical advice
• New or worsening bone pain or unexpected fracture – contact your doctor promptly to review denosumab treatment

Call 999 or go to A&E in an emergency, or contact NHS 111 for urgent advice.

When to Seek Medical Advice or Urgent Help

While tadalafil and denosumab can generally be taken together, you should contact your GP or pharmacist if you develop new symptoms or side effects after starting tadalafil [1][2]. For example, if you experience persistent headaches, visual disturbances, or unexplained muscle or joint pain, it is important to get these checked. Although these symptoms are more likely to be related to one medicine or the other rather than an interaction, your doctor can assess the cause and adjust your treatment if necessary.

Seek urgent medical help (call 999 or go to A&E) if you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, or chest pain during sexual activity [1][4]. These are rare but serious side effects of tadalafil that require immediate attention. If you have concerns about your bone health, such as new or worsening bone pain or an unexpected fracture, contact your doctor promptly, as this may require review of your denosumab treatment [12]. Always inform healthcare professionals that you are taking both medicines so they can provide the most appropriate care.