Tongkat ali (Eurycoma longifolia), a Southeast Asian herbal supplement, is often marketed for male sexual health, but does tongkat ali cause erectile dysfunction? This question arises from concerns about supplement safety rather than documented evidence. In the UK, tongkat ali is sold as a food supplement without the rigorous testing required for medicines. Whilst some preliminary research suggests potential benefits for sexual function, the evidence remains limited. Understanding the facts about tongkat ali, its safety profile, and when to seek medical advice for erectile dysfunction is essential for making informed decisions about your health.
Summary: There is no established evidence that tongkat ali causes erectile dysfunction; limited research suggests it may have neutral or potentially beneficial effects on sexual function.
- Tongkat ali is a food supplement in the UK, not a licensed medicine, and does not undergo rigorous pharmaceutical testing for safety or efficacy.
- The supplement may influence testosterone levels by reducing sex hormone-binding globulin, though evidence is based on small, short-term studies.
- Commonly reported side effects include insomnia, restlessness, and gastrointestinal disturbances, particularly at higher doses.
- Product quality varies significantly, with risks of contamination, adulterants, or inconsistent active ingredient concentrations.
- Erectile dysfunction persisting for three months or more requires GP assessment, as it can indicate cardiovascular disease or diabetes.
- Evidence-based ED treatments include PDE-5 inhibitors (such as sildenafil), lifestyle modifications, and psychological interventions as recommended by NICE.
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What Is Tongkat Ali and How Does It Work?
Tongkat ali (Eurycoma longifolia), also known as Malaysian ginseng or longjack, is a flowering plant native to Southeast Asia that has been used in traditional medicine for centuries. The root extract contains various bioactive compounds, including quassinoids, alkaloids, and eurypeptides.
Proponents suggest that tongkat ali may influence the hypothalamic-pituitary-gonadal axis, potentially supporting testosterone production by reducing sex hormone-binding globulin (SHBG) and thereby increasing the proportion of free testosterone available in the bloodstream. Some studies have also indicated that the extract may help modulate cortisol levels. However, these proposed mechanisms are based on limited human evidence, primarily from small, short-term trials, and the clinical significance remains uncertain.
In the UK, tongkat ali is available as a food supplement in various forms, including capsules, powders, and tinctures. These products are regulated as foods under the Food Standards Agency (FSA) and trading standards, not as medicines by the Medicines and Healthcare products Regulatory Agency (MHRA). This means they do not undergo the same rigorous testing for efficacy and safety as licensed pharmaceutical products, and manufacturers cannot make medicinal claims. There are no Traditional Herbal Registration (THR) products containing tongkat ali currently registered in the UK. The quality, purity, and concentration of active ingredients can vary significantly between manufacturers, and some products may contain contaminants or adulterants.
Whilst some preliminary research has shown promise for effects on male sexual health, energy levels, and athletic performance, the evidence base remains limited and of low to moderate quality. Many studies have been small-scale, short-duration, or conducted in animal models. The NHS does not currently provide specific guidance on tongkat ali, and it should not be considered a substitute for evidence-based medical interventions.
Potential Side Effects and Safety Considerations
Whilst tongkat ali is generally considered safe when taken at recommended doses for short periods, potential adverse effects have been reported. Commonly reported side effects may include insomnia, restlessness, and increased irritability, particularly when taken in higher doses or later in the day. Some users have also reported gastrointestinal disturbances such as nausea, stomach discomfort, or changes in bowel habits, though robust clinical data on frequency and severity are limited.
More concerning potential effects relate to hormonal changes. Because tongkat ali may influence testosterone levels, individuals with hormone-sensitive conditions should exercise caution. This includes men with prostate conditions, as elevated testosterone could theoretically affect prostate health, though evidence remains inconclusive.
Important safety considerations include:
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Drug interactions: Tongkat ali may theoretically interact with medications metabolised by liver enzymes (cytochrome P450 system), including some drugs for diabetes, blood pressure, or immunosuppression. These interactions are based primarily on in vitro data, and clinical significance is not well established. If you take regular medications, discuss supplement use with your GP or pharmacist.
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Quality concerns: As an unregulated food supplement, products may contain contaminants, adulterants, heavy metals, or inconsistent amounts of active ingredients. Some products tested have been found to contain undeclared substances. Purchase supplements only from reputable UK or EU suppliers, and consider products that have undergone third-party testing. Athletes should look for products certified by schemes such as Informed-Sport to reduce the risk of inadvertent doping violations.
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Liver safety: Rare cases of liver injury have been reported with herbal supplements, including some containing tongkat ali. Stop taking tongkat ali immediately and seek medical advice if you develop jaundice (yellowing of the skin or eyes), dark urine, pale stools, persistent nausea, or right upper abdominal pain.
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Lack of long-term safety data: Most studies have examined short-term use (weeks to months), and the effects of prolonged supplementation remain unknown.
Pregnant or breastfeeding women, children, and adolescents should avoid tongkat ali due to insufficient safety data. Individuals with significant liver or kidney disease should also avoid use or seek specialist advice before considering supplementation.
If you experience any suspected side effects from tongkat ali or any other supplement, you can report them via the MHRA Yellow Card Scheme (available online at yellowcard.mhra.gov.uk or via the Yellow Card app). Always discuss supplement use with a healthcare professional, particularly if you have existing health conditions or take regular medications.
When to Seek Medical Advice About Erectile Dysfunction
Erectile dysfunction (ED) is defined as the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. Whilst occasional difficulties are normal, persistent problems warrant medical evaluation. According to NICE guidance, ED can be an early indicator of cardiovascular disease, diabetes, or other significant health conditions, making proper assessment essential. ED is typically considered persistent if it lasts for three months or more, though earlier consultation is appropriate if you are concerned.
You should contact your GP if:
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Erectile difficulties persist for more than a few weeks or are worsening
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ED is accompanied by other symptoms such as reduced libido, fatigue, mood changes, or physical discomfort
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You experience sudden onset of ED, particularly if associated with trauma or following new medication
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You have cardiovascular risk factors (high blood pressure, high cholesterol, diabetes, smoking, obesity)
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ED is causing significant distress or affecting your relationship
Your GP will typically conduct a comprehensive assessment including medical history, physical examination, and relevant investigations. According to NICE Clinical Knowledge Summaries (CKS), blood tests may be arranged if clinically indicated, including:
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Testosterone: A morning sample (ideally around 9 am) should be taken if low libido or clinical features of hypogonadism are present. If testosterone is low, the test should be repeated, and further hormonal tests (luteinising hormone, follicle-stimulating hormone, prolactin) may be considered.
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HbA1c or fasting glucose: To screen for diabetes.
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Fasting lipid profile: To assess cardiovascular risk.
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Blood pressure, body mass index (BMI), and cardiovascular risk assessment (e.g., QRISK) should also be performed.
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A medication review is important, as some drugs can contribute to ED.
NICE recommends that lifestyle modifications should be discussed as first-line management, including smoking cessation, reducing alcohol intake, increasing physical activity, and achieving a healthy weight. Psychological factors, including stress, anxiety, and relationship issues, should also be explored, as these commonly contribute to ED.
Referral to specialist services may be appropriate if:
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There is penile deformity or suspected Peyronie's disease (urology referral)
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Testosterone remains persistently low or there are features of pituitary disease (endocrinology referral)
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There are significant psychosexual factors (consider psychosexual therapy or counselling)
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First-line treatments are ineffective or contraindicated
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Neurological signs are present
Seek urgent medical attention (attend A&E) if:
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You experience a painful erection lasting more than four hours (priapism)
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ED occurs suddenly alongside chest pain, breathlessness, or other cardiac symptoms
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You notice genital abnormalities, lumps, or significant pain
Remember that ED is a common condition that increases with age, and effective, evidence-based treatments are available through the NHS.
Does Tongkat Ali Cause Erectile Dysfunction?
There is no established evidence that tongkat ali causes erectile dysfunction. In fact, the supplement is often marketed with claims that it may improve sexual function, though these claims are based on limited, low-quality evidence from small, short-term studies. The concern about tongkat ali potentially causing ED likely stems from general anxiety about supplement side effects rather than documented clinical evidence.
The limited research available, including small randomised controlled trials and systematic reviews, suggests that tongkat ali is more likely to have neutral or potentially beneficial effects on erectile function rather than detrimental ones. Some studies have indicated possible improvements in erectile function scores among men taking standardised extracts, potentially related to modest increases in testosterone levels. However, these studies have significant limitations, including small sample sizes, short duration, variable product quality, and lack of long-term follow-up, making it difficult to draw definitive conclusions.
It is theoretically possible that individual responses to tongkat ali could vary. Some men might experience side effects such as anxiety, sleep disturbance, or hormonal fluctuations that could indirectly affect sexual function. Additionally, if a product is contaminated or contains undeclared ingredients, unexpected effects could occur. However, these scenarios would represent product quality issues or individual sensitivities rather than a direct causative relationship between pure tongkat ali and ED.
Important considerations:
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If you develop erectile difficulties after starting tongkat ali, discontinue use and consult your GP to rule out other causes.
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ED has numerous potential causes (vascular, hormonal, psychological, medication-related), and coincidental timing with supplement use does not establish causation.
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Self-treating ED with supplements may delay diagnosis of underlying health conditions that require medical attention.
The European Medicines Agency (EMA) has not approved tongkat ali for any medical indication, and it remains classified as a food supplement in the UK. If you are experiencing erectile dysfunction, evidence-based treatments have substantially more robust evidence supporting their use. These include:
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Phosphodiesterase-5 (PDE-5) inhibitors such as sildenafil, tadalafil, vardenafil, or avanafil, which are available via the NHS following clinical assessment. These medications have important contraindications (for example, they must not be used with nitrates for angina) and require proper medical evaluation. Refer to the British National Formulary (BNF) or discuss with your GP for full prescribing information.
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Lifestyle modifications as recommended by NICE.
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Psychological interventions or psychosexual therapy if appropriate.
Always discuss supplement use with your healthcare provider, particularly if you have existing health conditions or are considering using supplements to address medical concerns. For further information, consult the NICE Clinical Knowledge Summaries on erectile dysfunction or visit the NHS website.
Frequently Asked Questions
Can tongkat ali supplements actually cause erectile dysfunction?
No established evidence shows that tongkat ali causes erectile dysfunction. Limited research suggests the supplement may have neutral or potentially beneficial effects on sexual function, though studies are small and short-term, making definitive conclusions difficult.
What are the most common side effects of taking tongkat ali?
Common side effects include insomnia, restlessness, increased irritability, and gastrointestinal disturbances such as nausea or stomach discomfort, particularly when taken in higher doses or later in the day. These effects are generally mild but can affect quality of life.
Is tongkat ali safe to take with blood pressure medication?
Tongkat ali may theoretically interact with medications metabolised by liver enzymes, including some blood pressure drugs, though clinical significance is not well established. Always discuss supplement use with your GP or pharmacist before combining it with prescribed medications.
How does tongkat ali compare to prescription ED treatments like sildenafil?
Prescription PDE-5 inhibitors such as sildenafil have robust clinical evidence supporting their efficacy and safety for erectile dysfunction, whilst tongkat ali has limited, low-quality evidence. Licensed ED medications undergo rigorous testing and require proper medical assessment, whereas tongkat ali is an unregulated food supplement.
When should I see my GP about erectile dysfunction instead of trying supplements?
Contact your GP if erectile difficulties persist for more than a few weeks, worsen, or occur alongside other symptoms such as reduced libido, fatigue, or cardiovascular risk factors. ED can indicate underlying conditions like diabetes or heart disease, making proper medical assessment essential rather than self-treating with supplements.
How can I tell if a tongkat ali product is safe and good quality?
Purchase supplements only from reputable UK or EU suppliers and look for products that have undergone third-party testing. Athletes should choose products certified by schemes such as Informed-Sport, as unregulated supplements may contain contaminants, adulterants, or inconsistent amounts of active ingredients.
The health-related content published on this site is based on credible scientific sources and is periodically reviewed to ensure accuracy and relevance. Although we aim to reflect the most current medical knowledge, the material is meant for general education and awareness only.
The information on this site is not a substitute for professional medical advice. For any health concerns, please speak with a qualified medical professional. By using this information, you acknowledge responsibility for any decisions made and understand we are not liable for any consequences that may result.
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