Does fish oil cause erectile dysfunction? This is a common concern among men taking omega-3 supplements. Fish oil supplements contain omega-3 fatty acids (EPA and DHA) that support cardiovascular health and reduce inflammation. Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance, affecting many men, particularly those over 40. Given fish oil's cardiovascular effects, questions naturally arise about its impact on sexual function. This article examines the clinical evidence regarding fish oil and erectile function, clarifies common misconceptions, and explains when to seek medical advice for ED.

Understanding Fish Oil and Erectile Function

Fish oil supplements contain omega-3 long-chain polyunsaturated fatty acids, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are derived from oily fish such as salmon, mackerel, and sardines. These fatty acids play important roles in cardiovascular health, inflammation regulation, and cellular function throughout the body. Many people take fish oil supplements to support health, though it's worth noting that dietary sources (eating oily fish) are the preferred way to obtain omega-3s according to NHS guidance.

Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It affects a significant proportion of men, particularly those over 40 years of age, and can result from various physical and psychological factors. The mechanism of achieving an erection is complex, involving the nervous system, blood vessels, hormones, and psychological factors working in coordination.

Key physiological requirements for normal erectile function include:

• Adequate blood flow to the penile arteries

• Healthy endothelial function (the inner lining of blood vessels)

• Proper nerve signalling

• Balanced hormone levels, particularly testosterone

• Psychological wellbeing and sexual arousal

Vascular health is particularly crucial for erectile function, as erections depend on increased blood flow to the corpus cavernosum (erectile tissue). Conditions that impair blood vessel function—such as atherosclerosis, hypertension, diabetes, and high cholesterol—are well-established risk factors for ED. Given that fish oil is sometimes associated with cardiovascular health, questions naturally arise about whether it might influence erectile function positively or negatively. Understanding the relationship between fish oil supplementation and sexual health requires examining the available clinical evidence and biological mechanisms.

Does Fish Oil Cause Erectile Dysfunction?

There is no convincing clinical evidence that fish oil causes erectile dysfunction. ED is not listed as an adverse effect in UK Summaries of Product Characteristics (SmPCs) for licensed omega-3 products (such as omega-3-acid ethyl esters). The available research suggests that omega-3 fatty acids may have neutral or potentially beneficial effects on sexual function rather than harmful ones.

The theoretical concern about fish oil causing ED appears to stem from misunderstandings about its effects on the body. Some individuals may worry that because fish oil can have mild blood-thinning properties, it might somehow interfere with erectile function. However, the mechanism of erection relies on increased blood flow into the penis, and improved vascular function would theoretically support rather than impair this process.

Clinical studies examining omega-3 supplementation have not identified ED as a side effect. The most commonly reported adverse effects of fish oil supplements are gastrointestinal in nature, including:

• Fishy aftertaste or burping

• Nausea or indigestion

• Loose stools or diarrhoea

• Abdominal discomfort

It is important to consider that if someone experiences ED whilst taking fish oil, this is more likely coincidental than causal, though individual responses to supplements can vary. Erectile dysfunction has numerous established risk factors, including cardiovascular disease, diabetes, obesity, smoking, excessive alcohol consumption, certain medications (particularly some antihypertensives and antidepressants), psychological stress, and hormonal imbalances. If ED develops during fish oil supplementation, these other factors should be investigated as the more probable causes.

If you suspect any side effects from fish oil or other supplements, you should report them through the MHRA Yellow Card scheme.

When to Seek Medical Advice About Erectile Dysfunction

Erectile dysfunction should not be dismissed as simply an inevitable part of ageing or a minor inconvenience. It can be an early warning sign of underlying cardiovascular disease, as the penile arteries are smaller than coronary arteries and may show signs of atherosclerosis earlier. Men experiencing persistent or recurrent erectile difficulties should consult their GP for proper evaluation.

You should seek medical advice if you experience:

• Erectile difficulties on most occasions over a period of several weeks or months

• Sudden onset of ED, particularly in younger men

• Loss of morning erections

• ED accompanied by other symptoms such as chest pain, shortness of breath, or leg pain when walking

• Reduced libido or other signs of hormonal imbalance

• Psychological distress or relationship difficulties related to sexual function

If you have chest pain suggestive of a heart attack or severe shortness of breath, call 999 immediately.

Your GP will typically conduct a thorough assessment following NICE guidance, which includes taking a detailed medical and sexual history, reviewing current medications, and performing a physical examination. Blood tests may be arranged to check for diabetes (HbA1c), cholesterol levels, morning testosterone, and thyroid function. This evaluation helps identify treatable underlying causes and cardiovascular risk factors.

It is particularly important not to self-diagnose or attribute ED to supplements like fish oil without medical assessment. Many men delay seeking help due to embarrassment, but ED is a common medical condition that can often be effectively managed. Early consultation allows for identification of serious underlying conditions such as diabetes or cardiovascular disease, which require prompt treatment.

Your GP can also advise whether any supplements you are taking might interact with other medications or whether they should be continued. Note that PDE-5 inhibitors (e.g., sildenafil) are not suitable if you take nitrates for angina—your GP will advise on treatment options. Remember that effective treatments for ED are available through the NHS, and addressing the condition can significantly improve quality of life and may identify important health risks that require attention.

How Fish Oil May Affect Sexual Health

Rather than causing erectile dysfunction, omega-3 fatty acids found in fish oil may theoretically support aspects of sexual health through several biological mechanisms, though the evidence for direct benefits on erectile function specifically remains limited. Fish oil should not be considered a treatment for erectile dysfunction.

Potential mechanisms by which fish oil might support sexual health include:

• Endothelial function improvement: Omega-3 fatty acids may enhance the function of the endothelium (blood vessel lining), potentially promoting better nitric oxide production. Nitric oxide is essential for vasodilation and increased blood flow to erectile tissue.

• Anti-inflammatory effects: Chronic inflammation can impair vascular function. EPA and DHA have anti-inflammatory properties that may help maintain healthy blood vessels.

• Lipid profile effects: Fish oil can reduce triglycerides in some cases, though its effects on overall cholesterol profiles are more modest.

• Blood pressure effects: Some studies suggest modest blood pressure reductions with omega-3 supplementation, which may benefit vascular health.

It's important to note that NICE guidance does not recommend routine omega-3 supplements for cardiovascular disease prevention. The NHS recommends obtaining omega-3 fatty acids through diet, specifically by eating at least two portions of fish per week, including one portion of oily fish.

For men taking fish oil supplements or prescribed omega-3 medicines for specific purposes, there is no evidence to suggest discontinuation due to concerns about erectile function. However, individuals taking anticoagulant or antiplatelet medications should consult their GP before starting fish oil due to potential additive blood-thinning effects that may require monitoring. Additionally, high-dose prescription omega-3 products have been associated with increased atrial fibrillation risk in some studies; patients with existing heart rhythm disorders should seek medical advice.

Overall, maintaining a healthy lifestyle—including regular exercise, a balanced diet rich in fruits and vegetables, maintaining a healthy weight, limiting alcohol, and not smoking—remains the foundation for both cardiovascular and sexual health.

Frequently Asked Questions