Erectile dysfunction (ED) medicines such as sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) are widely used to treat male sexual dysfunction, but their relationship with migraine is often misunderstood. Many patients wonder whether these medicines might help prevent migraines, whilst others experience headaches as an unwanted side effect. The reality is that PDE5 inhibitors are not licensed in the UK for migraine prevention and, in fact, headache is one of the most commonly reported adverse effects. Understanding how these medicines affect blood vessels and headache patterns is essential for anyone managing both conditions safely and effectively.

Understanding the Link Between Erectile Dysfunction Medicines and Migraine

Erectile dysfunction (ED) medicines, particularly phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra), are widely prescribed for male sexual dysfunction. However, their relationship with migraine is complex and often misunderstood. Many patients wonder whether these medicines might help prevent migraines, whilst others experience headaches as an unwanted side effect.

PDE5 inhibitors are not licensed or approved in the UK for preventing or treating migraine. In fact, headache is one of the most commonly reported adverse effects of PDE5 inhibitors, classified as very common (affecting more than 1 in 10 people) according to the Medicines and Healthcare products Regulatory Agency (MHRA) and product information. These medicine-induced headaches can range from mild tension-type headaches to more severe headaches that may mimic migraine symptoms. The mechanism behind this lies in how these drugs affect blood vessel function throughout the body, not just in the genital area.

For individuals who already suffer from migraine, the introduction of ED medicines may complicate their headache pattern. Some patients report that their migraines become more frequent or severe when taking these drugs, whilst others notice no change. Understanding this relationship is crucial for both patients and healthcare professionals when weighing the benefits of ED treatment against potential neurological side effects.

It is important to distinguish between medication-overuse headache (headache occurring on 15 or more days per month developing as a consequence of regular overuse of acute headache medication), migraine triggers, and the direct pharmacological effects of ED medicines. If you experience migraine and are considering ED treatment, discussing your complete headache history with your GP or specialist is essential for safe prescribing and optimal management of both conditions.

How ED Medicines Affect Blood Vessels and Headaches

PDE5 inhibitors work by blocking the enzyme phosphodiesterase type 5, which leads to increased levels of cyclic guanosine monophosphate (cGMP) in smooth muscle cells. This biochemical cascade causes vasodilation—the widening of blood vessels—which improves blood flow to the penis, facilitating erection. PDE5 inhibitors potentiate the nitric oxide–soluble guanylate cyclase–cGMP signalling pathway, and this vasodilatory effect can occur in blood vessels throughout the body, including cranial and meningeal vessels, which explains why these medicines can trigger headaches.

When ED medicines cause vasodilation in cranial blood vessels, this can trigger headaches through several mechanisms. The dilation of meningeal blood vessels and activation of perivascular nerve fibres can stimulate pain pathways similar to those involved in migraine. Whilst some research has explored whether molecules such as calcitonin gene-related peptide (CGRP)—a key molecule in migraine pathophysiology—might be involved, the clinical reality is that the vasodilatory effects of PDE5 inhibitors tend to provoke rather than prevent headaches.

The intensity and duration of headaches vary between different ED medicines due to their pharmacokinetic profiles. Sildenafil has a relatively short half-life of 3–5 hours, meaning headache side effects typically resolve within hours. Tadalafil, with its much longer half-life of up to 17.5 hours, may cause more prolonged headache symptoms. Vardenafil and avanafil fall between these in terms of duration of action.

Clinical evidence does not support the use of PDE5 inhibitors as migraine preventatives, and the MHRA has not approved these medicines for headache disorders. The predominant clinical observation remains that ED medicines are more likely to cause or worsen headaches rather than alleviate them.

Clinical Evidence: Can ED Drugs Prevent or Trigger Migraines?

The scientific literature consistently demonstrates that ED medicines are headache triggers rather than treatments. In clinical trials, headache is classified as a very common adverse effect (affecting 1 in 10 people or more) across all PDE5 inhibitors. The European Medicines Agency (EMA) and MHRA product information confirm headache as one of the most frequently reported side effects, alongside flushing and nasal congestion.

Systematic reviews examining adverse effects of PDE5 inhibitors have found no evidence supporting their use in migraine prevention. Conversely, case reports have documented instances where these medicines triggered severe migraine attacks in susceptible individuals, sometimes accompanied by aura or other neurological symptoms. There is no official link between ED medicines and migraine relief, and no randomised controlled trials support this indication.

For patients with pre-existing migraine, the evidence suggests caution when initiating ED treatment. Studies indicate that individuals with a history of migraine may be more likely to experience severe headaches when taking PDE5 inhibitors. However, not all migraine sufferers will experience worsening symptoms, and some tolerate these medicines well. The response appears highly individual, emphasising the importance of personalised medical assessment and monitoring when managing both conditions.

If you experience headaches after taking ED medicines, you should report suspected side effects via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or search for Yellow Card in the Google Play or Apple App Store.

NHS Guidance on Using ED Medicines Safely with Migraine

The NHS recommends that patients disclose their complete medical history, including migraine, before starting ED medicines. Whilst migraine is not an absolute contraindication to PDE5 inhibitors, healthcare professionals should consider the potential for increased headache frequency or severity when prescribing these drugs. According to NICE Clinical Knowledge Summaries (CKS) for erectile dysfunction, sildenafil is usually started at 50 mg taken on demand approximately one hour before sexual activity, with dose adjustment to 25–100 mg based on response and tolerability. Starting at a lower dose may help assess tolerability in patients with headache disorders.

PDE5 inhibitors are contraindicated in patients taking:

• Nitrates (such as glyceryl trinitrate for angina) due to the risk of severe hypotension

• Riociguat (a guanylate cyclase stimulator) due to additive hypotensive effects

PDE5 inhibitors should be used with caution in patients:

• Taking alpha-blockers (risk of symptomatic hypotension)

• Taking potent CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole) which increase PDE5 inhibitor levels

• With recent myocardial infarction or stroke

• With severe hypotension or uncontrolled hypertension

• With anatomical deformation of the penis or conditions predisposing to priapism

Patients should inform their GP about all medicines, including those for migraine prevention or acute treatment. The NHS advises patients to monitor for headache patterns when starting ED medicines. If headaches are mild and transient, they often improve with continued use as the body adjusts. However, if headaches are severe, persistent, or represent a significant change from usual migraine patterns, medical review is necessary.

Contact your GP if you experience:

• Severe headache that is different from your usual headaches

• Headache accompanied by visual disturbances, weakness, or speech difficulties

• Headache that persists beyond 24 hours after medicine use

• Increasing frequency or severity of migraines after starting ED treatment

Call 999 or go to A&E immediately if you experience:

• Thunderclap headache (sudden, severe onset reaching maximum intensity within seconds to minutes)

• Headache with fever, stiff neck, confusion, or altered consciousness

• Headache following head injury

• New neurological symptoms (weakness, numbness, vision loss, difficulty speaking)

For urgent but non-emergency concerns, you can contact NHS 111 for advice.

For some patients, switching between different PDE5 inhibitors may improve tolerability, as individual responses vary. Tadalafil's longer duration might suit those who prefer less frequent dosing, though this may prolong headache side effects. Alternatively, on-demand dosing with shorter-acting agents like sildenafil or avanafil allows patients to time medicine use around important activities whilst minimising overall exposure.

Alternative Migraine Treatments and When to Seek Medical Advice

For patients experiencing both ED and migraine, managing both conditions requires a coordinated approach. NICE-recommended migraine treatments include acute therapies such as triptans (sumatriptan, rizatriptan), NSAIDs (ibuprofen, naproxen), and antiemetics. For migraine prevention, options include propranolol, topiramate, amitriptyline, and newer CGRP monoclonal antibodies. NICE has approved erenumab, fremanezumab, galcanezumab, and eptinezumab for preventing migraine in adults who have at least 4 migraine days per month, subject to specific eligibility criteria outlined in the relevant NICE Technology Appraisals.

Patients should be aware that triptans work by causing cranial vasoconstriction, whilst PDE5 inhibitors cause vasodilation—opposite mechanisms. Whilst there is no absolute contraindication to using both, individual assessment is important, and you should discuss this combination with your GP. Always check the British National Formulary (BNF) or consult your pharmacist for potential interactions. Nitrates and riociguat remain contraindicated with PDE5 inhibitors, and caution is advised with alpha-blockers and antihypertensive medicines due to additive blood pressure-lowering effects.

Maintaining a headache diary can help identify whether ED medicines are triggering migraines or whether headaches are part of your natural migraine pattern. If you are using acute headache medicines frequently, be aware of medication-overuse headache, which can develop when:

• Triptans, ergots, opioids, or combination analgesics are used on 10 or more days per month for more than 3 months

• Simple analgesics (paracetamol, aspirin, NSAIDs) are used on 15 or more days per month for more than 3 months

Non-pharmacological approaches may benefit both conditions. Lifestyle modifications such as regular exercise, stress management, adequate sleep, and avoiding known migraine triggers (certain foods, alcohol, dehydration) can reduce migraine frequency. For ED, addressing cardiovascular risk factors, psychological factors, and relationship issues may reduce reliance on medicine or improve treatment outcomes.

Seek urgent medical advice by calling 999 or going to A&E if you experience:

• Thunderclap headache (sudden, severe onset)

• Headache with fever, stiff neck, confusion, or altered consciousness

• Headache following head injury

• New headache patterns after age 50 with progressive worsening

• Headache with new neurological signs (weakness, vision loss, speech difficulty)

For routine concerns about managing ED medicines alongside migraine, book an appointment with your GP or specialist. They can review your treatment plan, consider alternative ED therapies (such as vacuum devices, intracavernosal injections, or psychological interventions), and ensure your migraine management is optimised according to NICE guidance on headaches in over 12s. A holistic approach addressing both conditions will provide the best outcomes for your overall health and quality of life.

Remember to report any suspected side effects from ED medicines via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Frequently Asked Questions