Repatha (evolocumab) is a PCSK9 inhibitor prescribed to lower cholesterol in patients with familial hypercholesterolaemia and other lipid disorders. Some men taking cholesterol medications may experience erectile dysfunction (ED) and wonder whether their treatment is responsible. This article examines the evidence linking Repatha to erectile dysfunction, explores the relationship between cardiovascular health and sexual function, and provides guidance on managing ED whilst maintaining essential cholesterol control. Understanding these connections helps patients make informed decisions about their cardiovascular treatment.

What Is Repatha and How Does It Work?

Repatha (evolocumab) is a prescription medicine used to lower cholesterol levels. In the UK, it is licensed for adults with primary hypercholesterolaemia (including familial hypercholesterolaemia and non-familial hypercholesterolaemia), mixed dyslipidaemia, and for adults and adolescents aged 12 years and older with homozygous familial hypercholesterolaemia (HoFH). It belongs to a class of drugs called PCSK9 inhibitors, which work differently from traditional statins.

Repatha functions by blocking a protein called proprotein convertase subtilisin/kexin type 9 (PCSK9) in the liver. Normally, PCSK9 reduces the number of receptors available to remove low-density lipoprotein cholesterol (LDL-C, or 'bad' cholesterol) from the blood. By inhibiting PCSK9, Repatha increases the liver's ability to clear LDL-C from the bloodstream, resulting in significantly lower cholesterol levels.

The medication is administered as a subcutaneous injection, typically as 140 mg every two weeks or 420 mg once monthly, depending on the prescribed regimen. It is often used in combination with statins and dietary modifications when these measures alone have not achieved adequate cholesterol control. According to NICE Technology Appraisal (TA394), Repatha is recommended for specific patient groups with persistently high LDL-C levels despite maximum tolerated lipid-lowering therapy, with specific thresholds depending on cardiovascular risk category.

Common side effects of Repatha include injection site reactions, nasopharyngitis, upper respiratory tract infections, influenza, back pain, and arthralgia. Serious allergic reactions are rare but require immediate medical attention. If you experience any side effects, talk to your doctor or pharmacist. You can also report side effects directly via the Yellow Card Scheme at yellowcard.mhra.gov.uk. The MHRA continues to monitor the safety profile of PCSK9 inhibitors, and current evidence supports their efficacy in reducing cardiovascular events when used appropriately.

Understanding Erectile Dysfunction and Cholesterol Medications

Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity. It affects a significant proportion of men, particularly those over 40, and can have multiple underlying causes including cardiovascular disease, diabetes, hormonal imbalances, psychological factors, and certain medications.

The relationship between cholesterol-lowering medications and erectile function is complex. High cholesterol itself is a risk factor for ED because it contributes to atherosclerosis—the narrowing and hardening of blood vessels, including those supplying the penis. Adequate blood flow is essential for erectile function, so cardiovascular disease and ED often coexist. In fact, ED can be an early warning sign of underlying cardiovascular problems.

Regarding Repatha specifically, there is no established clinical evidence linking evolocumab to erectile dysfunction. The UK Summary of Product Characteristics (SmPC) for Repatha does not list ED as a recognised adverse effect. Clinical trials involving thousands of patients have not identified a significant association between PCSK9 inhibitors and sexual dysfunction.

With statins—which are often prescribed alongside Repatha—the evidence is mixed. Some patients have reported erectile difficulties, but most systematic reviews and meta-analyses show either no association with ED or even slight improvements in erectile function, likely due to better vascular health. It is important to recognise that the underlying cardiovascular disease being treated, rather than the medication itself, may be the primary contributor to ED.

If you are experiencing erectile dysfunction whilst taking Repatha or any cholesterol medication, it is essential to discuss this with your GP rather than discontinuing treatment, as uncontrolled cholesterol poses serious cardiovascular risks.

What to Do If You Experience Erectile Dysfunction on Repatha

If you develop erectile dysfunction whilst taking Repatha, it is important to approach the situation systematically and not to stop your medication without medical advice. Discontinuing cholesterol treatment can significantly increase your risk of heart attack or stroke, particularly if you have established cardiovascular disease.

First steps include scheduling an appointment with your GP to discuss your symptoms. Your doctor will take a comprehensive history to understand the timeline of your ED in relation to starting Repatha, assess other potential contributing factors, and review all your current medications. Many commonly prescribed drugs—including certain blood pressure medications, antidepressants, and antihistamines—can affect erectile function.

Your GP may recommend investigations to identify underlying causes, which might include:

• Blood tests including morning serum total testosterone (repeated if low and symptoms suggest hypogonadism), HbA1c (to screen for diabetes), and lipid profiles

• Blood pressure measurement and cardiovascular risk assessment

• Review of psychological factors such as stress, anxiety, or depression

• Assessment of lifestyle factors including alcohol consumption, smoking, and physical activity levels

According to NICE guidance, management of ED should address modifiable risk factors and underlying health conditions. Your doctor may suggest lifestyle modifications such as increasing physical activity, achieving a healthy weight, reducing alcohol intake, and stopping smoking—all of which benefit both cardiovascular health and erectile function.

If Repatha is deemed necessary for your cardiovascular protection, your GP will work with you to manage ED through other means rather than discontinuing the cholesterol medication. This patient-centred approach ensures you receive optimal treatment for both conditions. Never adjust your Repatha dose or stop treatment independently, as this could have serious health consequences. Open communication with your healthcare team is essential for finding the most appropriate management strategy for your individual circumstances.

Alternative Treatments and When to Speak to Your GP

If erectile dysfunction persists despite addressing lifestyle factors, several evidence-based treatment options are available through the NHS. The first-line pharmacological treatment typically involves phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil. These medications enhance erectile function by improving blood flow to the penis and have proven efficacy in men with various underlying causes of ED, including those with cardiovascular disease.

Your GP will assess whether PDE5 inhibitors are safe for you. These medications are contraindicated if you take nitrates or nicorandil for angina, as the combination can cause dangerous drops in blood pressure. Caution is also needed if you take alpha-blockers for prostate conditions or high blood pressure. If you experience an erection lasting more than 4 hours (priapism) after taking ED medication, seek urgent medical attention.

Other treatment options may include vacuum erection devices, intracavernosal injections, or referral to specialist services for more complex cases. Psychological support or psychosexual counselling may be beneficial if anxiety, stress, or relationship issues contribute to the problem.

Regarding your cholesterol management, if there are concerns about your current regimen, your doctor might consider:

• Reviewing all medications for temporal associations with ED onset, while recognising that statins generally do not increase ED risk and may even improve erectile function in some men

• Optimising other cardiovascular medications that might affect erectile function

• Reviewing the necessity of continuing Repatha based on your cholesterol levels and cardiovascular risk

You should contact your GP promptly if:

• Erectile dysfunction develops suddenly or worsens significantly

• You experience chest pain, breathlessness, or other cardiovascular symptoms

• ED is accompanied by reduced libido, fatigue, or mood changes (possible hormonal issues)

• The condition is causing significant psychological distress or relationship difficulties

Your GP may refer you to a specialist if you have complex health needs, don't respond to initial treatments, have hormonal abnormalities, or have anatomical conditions like Peyronie's disease. Remember that erectile dysfunction is a common medical condition that can be effectively managed. Your GP is accustomed to discussing these concerns and can provide confidential, professional advice tailored to your circumstances.

Frequently Asked Questions