Glucagon-like peptide-1 (GLP-1) receptor agonists, including semaglutide and liraglutide, are increasingly prescribed for type 2 diabetes and weight management across the UK. As their use expands, questions have emerged about potential effects on sexual health, particularly whether GLP-1 medications cause erectile dysfunction in men. Current clinical evidence does not establish a direct causal link between GLP-1 therapy and erectile dysfunction. In fact, these medications may potentially improve erectile function in some men through better glycaemic control, weight reduction, and improved cardiovascular health. Understanding the relationship between GLP-1 medications and erectile function requires consideration of underlying conditions, concurrent medications, and other contributing factors.

What Are GLP-1 Medications and How Do They Work?

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of medications primarily prescribed for the management of type 2 diabetes mellitus and, in some cases, for weight management in adults with obesity or overweight with weight-related comorbidities. Common examples include semaglutide (Ozempic, Wegovy, Rybelsus), liraglutide (Victoza, Saxenda), dulaglutide (Trulicity), and tirzepatide (Mounjaro), which is a dual GLP-1 and GIP receptor agonist.

These medications work by mimicking the action of naturally occurring GLP-1, a hormone released by the intestine in response to food intake. GLP-1 receptor agonists enhance glucose-dependent insulin secretion from pancreatic beta cells, suppress inappropriate glucagon release, slow gastric emptying, and reduce appetite through central nervous system pathways. This multifaceted mechanism leads to improved glycaemic control in people with type 2 diabetes and significant weight loss in those using these agents for obesity management.

The pharmacological profile of GLP-1 medications varies by agent. Some are short-acting (requiring daily administration), whilst others are long-acting formulations given once weekly. Most are administered via subcutaneous injection, though oral semaglutide (Rybelsus) is available for type 2 diabetes only. The MHRA has authorised these medications following rigorous clinical trials demonstrating their efficacy and safety profile.

It's important to note that not all GLP-1 medications are authorised for weight management in the UK. For example, dulaglutide (Trulicity) is only authorised for type 2 diabetes, while semaglutide 2.4mg (Wegovy) and liraglutide 3mg (Saxenda) have specific authorisations for weight management with eligibility criteria defined by NICE guidance.

Given their increasing use across the UK, questions have emerged regarding potential effects on sexual function, particularly erectile dysfunction (ED) in men. Understanding the mechanism of action helps contextualise whether these medications could plausibly influence erectile function directly or indirectly through their metabolic effects.

Does GLP-1 Cause Erectile Dysfunction?

There is no established direct causal link between GLP-1 receptor agonists and erectile dysfunction based on current clinical evidence. Large-scale randomised controlled trials and post-marketing surveillance data have not identified ED as a common or characteristic adverse effect of these medications. The Summary of Product Characteristics (SmPCs) for major GLP-1 agents authorised by the MHRA does not list erectile dysfunction among recognised adverse reactions.

In fact, some evidence suggests that GLP-1 medications may potentially improve erectile function in some men, particularly those with type 2 diabetes and obesity—two conditions strongly associated with ED. Several mechanisms might explain possible benefits:

• Improved glycaemic control: Better blood glucose regulation may reduce endothelial dysfunction and microvascular damage, both implicated in ED pathophysiology

• Weight reduction: Significant weight loss can improve testosterone levels, reduce inflammation, and enhance vascular function

• Cardiovascular effects: GLP-1 agents may improve endothelial function and reduce cardiovascular risk factors that contribute to ED

• Reduced inflammation: These medications have been associated with anti-inflammatory effects that might benefit vascular health, though more research is needed

Some observational studies have reported improvements in erectile function scores among men with diabetes treated with GLP-1 receptor agonists, though the evidence is limited and more robust research is needed. It is important to note that if ED develops or worsens during GLP-1 therapy, this is more likely related to the underlying conditions being treated (diabetes, obesity, cardiovascular disease) or other concurrent factors rather than the medication itself.

Patients concerned about sexual function should discuss this openly with their GP, as attributing symptoms to GLP-1 therapy without proper assessment may lead to unnecessary discontinuation of beneficial treatment. If you suspect any medication is causing side effects, you can report this through the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Other Factors That Affect Erectile Function During GLP-1 Therapy

When erectile dysfunction occurs in men taking GLP-1 medications, it is essential to consider the multifactorial nature of ED and the numerous contributing factors that may coincide with GLP-1 therapy rather than being caused by it.

Underlying medical conditions are often the primary culprits. Type 2 diabetes—the most common indication for GLP-1 therapy—is independently associated with a two- to threefold increased risk of ED due to neuropathy, endothelial dysfunction, and reduced nitric oxide availability. Cardiovascular disease, hypertension, and dyslipidaemia (frequently present in patients prescribed GLP-1 agents) all impair the vascular mechanisms essential for achieving and maintaining erections.

Other medications commonly prescribed alongside GLP-1 therapy may contribute to erectile difficulties:

• Antihypertensives: Beta-blockers and thiazide diuretics are recognised causes of ED

• Antidepressants: Selective serotonin reuptake inhibitors (SSRIs) frequently impair sexual function

• 5-alpha-reductase inhibitors: Finasteride and dutasteride for prostate conditions can affect sexual function

• Antipsychotics: Can impact sexual function through various mechanisms

• Opioids: May reduce testosterone levels and affect sexual desire and function

• Spironolactone: Can cause hormonal effects that impact erectile function

The relationship between statins and erectile function is complex, with mixed evidence. While some men report ED with statin therapy, these medications may actually improve endothelial function in others. Never stop prescribed medications without consulting your GP.

Psychological factors play a significant role in erectile function. Anxiety, depression, stress, and relationship difficulties can all manifest as ED. Men undergoing significant lifestyle changes, including weight loss programmes, may experience body image concerns or psychological adjustment that affects sexual confidence.

Lifestyle factors remain crucial. Smoking, excessive alcohol consumption, physical inactivity, and poor sleep quality all contribute to erectile difficulties. During periods of significant weight loss, some men may experience temporary changes in energy levels that could influence sexual function, though this typically resolves with adaptation.

A comprehensive assessment by your GP of all these factors is necessary before attributing erectile dysfunction to any single cause, including GLP-1 medication.

When to Speak to Your GP About Erectile Dysfunction

Erectile dysfunction warrants medical attention regardless of whether you are taking GLP-1 medications, as it may signal underlying health conditions requiring investigation and management. You should arrange to speak with your GP if:

• ED persists for more than a few weeks or is worsening over time

• You experience sudden onset of erectile difficulties, particularly if previously unaffected

• ED is accompanied by other symptoms such as reduced libido, fatigue, mood changes, or urinary problems

• You have cardiovascular risk factors (diabetes, hypertension, high cholesterol, smoking) as ED may be an early marker of cardiovascular disease

• Erectile difficulties are causing significant distress or affecting your relationship and quality of life

Seek urgent medical attention if you experience:

• Chest pain or shortness of breath during sexual activity

• An erection lasting more than 4 hours (priapism)

• Significant penile pain, sudden curvature, or trauma

• Neurological symptoms such as sudden weakness or speech difficulties

NICE guidance recommends that healthcare professionals take a thorough history when assessing ED, including:

• Medical history (diabetes, cardiovascular disease, neurological conditions, previous pelvic surgery)

• Medication review (prescription and over-the-counter preparations)

• Psychological and relationship factors

• Lifestyle factors (smoking, alcohol, exercise, sleep)

Initial investigations typically include blood tests to assess:

• Fasting glucose and HbA1c (glycaemic control)

• Lipid profile (cardiovascular risk)

• Morning testosterone levels (may need repeating if low)

• Thyroid function, prolactin, renal and liver function tests if clinically indicated

Your GP can provide appropriate management, which may include lifestyle modification advice, medication review, treatment of underlying conditions, or referral to specialist services (urology, endocrinology, or psychosexual counselling) if needed. Phosphodiesterase-5 (PDE5) inhibitors such as sildenafil are often effective first-line treatments and are generally safe to use alongside GLP-1 medications, though they are contraindicated with nitrate medications and riociguat, and should be used with caution in unstable cardiovascular disease or if taking alpha-blockers. Your doctor will assess suitability based on your individual circumstances.

Do not discontinue GLP-1 therapy without medical advice if you develop ED, as the benefits of these medications for diabetes control and cardiovascular risk reduction are substantial, and ED is unlikely to be directly caused by the medication itself.

Frequently Asked Questions