Eurycoma
Also known as: Tongkat Ali, Longjack, Eurycoma longifolia
Overview
Eurycoma longifolia, commonly known as Tongkat Ali or Longjack, is a medicinal plant native to Southeast Asia. Traditionally, its roots have been used to enhance male sexual health, vitality, and as an anti-aging agent. It is primarily consumed as a standardized root extract in supplement form. Key applications supported by research include increasing testosterone levels, improving male fertility, enhancing mood, boosting energy, and potentially regulating sleep. While research is ongoing, several randomized controlled trials and systematic reviews indicate its efficacy, particularly in testosterone enhancement. However, more large-scale clinical trials are needed to establish comprehensive clinical guidelines for all its purported benefits. The quality of evidence is moderate, with strong support for testosterone effects, while other benefits require further validation.
Benefits
The primary and most robustly supported benefit of Eurycoma longifolia is its ability to significantly increase serum total testosterone levels, especially in men with hypogonadism. A meta-analysis of five randomized controlled trials demonstrated a standardized mean difference of 1.352, indicating a strong positive effect on testosterone. This increase is statistically significant and clinically meaningful for hypogonadal individuals. Secondary benefits include improvements in mood, reduction in stress hormone profiles (like cortisol), and decreased fatigue. Some animal studies suggest enhanced sleep quality and circadian rhythm regulation, though human data are limited for these effects. Eurycoma longifolia appears particularly beneficial for men experiencing low testosterone and middle-aged adults dealing with fatigue or mood disturbances. While the testosterone increase is well-quantified, the mood and sleep benefits are promising but require further rigorous human studies for definitive quantification.
How it works
Eurycoma longifolia exerts its effects primarily through bioactive compounds known as quassinoids. These compounds are believed to stimulate the hypothalamic-pituitary-gonadal (HPG) axis, which is crucial for regulating hormone production, thereby leading to increased testosterone synthesis. Beyond hormonal regulation, Eurycoma longifolia may also modulate stress hormones such as cortisol, contributing to improved mood and reduced fatigue. Animal studies suggest a potential mechanism for sleep improvement by enhancing slow-wave activity and consolidating non-REM sleep phases, indicating an influence on sleep architecture. The effectiveness of the supplement is highly dependent on the standardization of the extract, with quassinoid content being a critical factor for its bioactivity and absorption.
Side effects
Eurycoma longifolia is generally considered safe for consumption, with clinical trials reporting a low incidence of adverse effects. While specific common side effects (occurring in more than 5% of users) are not extensively documented, mild gastrointestinal discomfort has been anecdotally reported. Uncommon or rare side effects have not been clearly identified in high-quality studies. There are no significant drug interactions or contraindications that have been conclusively established; however, caution is advised for individuals with hormone-sensitive conditions due to its impact on testosterone levels. As with many supplements, there is insufficient safety data for special populations such as pregnant or lactating women, and its use in these groups is not recommended without medical supervision. Long-term safety data beyond short to medium-term use are also limited, necessitating further research.
Dosage
Effective dosages of Eurycoma longifolia in clinical trials typically range from 200 mg to 400 mg of standardized extract daily. The optimal dosage is highly dependent on the extract's standardization, particularly its concentration of quassinoids, which are the primary bioactive compounds. Consistent daily dosing is recommended to achieve desired effects, with most studies showing benefits accruing over several weeks of continuous use. For optimal efficacy, it is crucial to use standardized root extracts that specify their quassinoid content to ensure consistent bioactivity. While absorption may be enhanced when taken with meals, specific cofactors that significantly improve absorption are not well-defined. There are no clearly established upper limits or safety thresholds beyond the typical therapeutic ranges, but adherence to recommended dosages is advised.
FAQs
Is Tongkat Ali safe for long-term use?
Current evidence supports the safety of Tongkat Ali for short to medium-term use. However, comprehensive data on its long-term safety, beyond several months, are still limited and require further research.
How soon can benefits be expected from Tongkat Ali?
Improvements in testosterone levels and mood may begin to appear within a few weeks of consistent supplementation, though individual responses can vary based on dosage and extract quality.
Can Tongkat Ali be used to treat erectile dysfunction?
While some evidence suggests Tongkat Ali may improve aspects of erectile function, more rigorous and large-scale clinical trials are needed to conclusively establish its efficacy as a treatment for erectile dysfunction.
Does Tongkat Ali affect sleep?
Animal studies indicate that Tongkat Ali may improve sleep quality by influencing sleep-wake cycles. However, human data on its effects on sleep are currently limited and require further investigation.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/36013514/ – This systematic review and meta-analysis by Leisegang et al. (2022) included 9 studies, with 5 randomized controlled trials in the meta-analysis. It found a significant increase in testosterone levels (SMD=1.352, p=0.001) in men, including hypogonadal subgroups, supplemented with Eurycoma longifolia. The study highlights the efficacy of the supplement for testosterone enhancement despite limitations like moderate sample sizes and heterogeneity in extract formulations.
- https://magistralbr.caldic.com/storage/product-files/445511096.pdf – The Natural Standard Systematic Review (2012) provides a comprehensive, evidence-based overview of Eurycoma longifolia, consolidating information on human efficacy, dosing, safety, and mechanisms of action. It supports the supplement's role in testosterone enhancement and its general safety profile, while also emphasizing the need for more rigorous clinical trials to further validate its benefits.
- https://academic.oup.com/sleepadvances/article/5/1/zpae047/7710213 – This preclinical study (2024) investigated the effects of Eurycoma longifolia on sleep in animal models. It demonstrated dose-dependent improvements in sleep-wake cycles and increased slow-wave activity in mice, suggesting potential neurophysiological benefits related to sleep. While promising, the study notes that these findings are from an animal model and require confirmation in human subjects.
