Eurycoma Longifolia Jack Extract
Also known as: Tongkat Ali, Longjack, Eurycoma longifolia Jack
Overview
Eurycoma longifolia Jack, commonly known as Tongkat Ali or Longjack, is a medicinal plant native to Southeast Asia. Its root extract is widely used as a dietary supplement, primarily for its purported testosterone-enhancing, aphrodisiac, and adaptogenic properties. Traditionally, it has been utilized to improve male sexual health, fertility, and physical performance. Research on Eurycoma longifolia is moderately mature, with several randomized controlled trials (RCTs) and systematic reviews focusing on its effects on testosterone levels and male reproductive health. While some high-quality evidence supports its efficacy, particularly in men with low testosterone, further large-scale clinical trials are needed to solidify certain claims and establish long-term safety.
Benefits
Eurycoma longifolia has demonstrated significant benefits, particularly in male reproductive health. The most robust evidence supports its ability to increase serum total testosterone levels in men, including both healthy individuals and those with hypogonadism. A meta-analysis of five RCTs showed a standardized mean difference (SMD) of 1.352 (95% CI 0.565 to 2.138, p=0.001), indicating a strong effect size for testosterone enhancement. This benefit is particularly relevant for men with low testosterone. Additionally, improvements in sperm quality and fertility parameters have been reported, with one study noting spontaneous pregnancies in 14.7% of treated patients, suggesting clinically meaningful reproductive benefits. There is also potential for improved erectile function, supported by systematic reviews, though more data are needed to confirm the extent of this effect. In vitro and animal studies have shown antimicrobial and antiparasitic activity, but the clinical relevance of these effects requires further validation. Testosterone increases are typically observed within weeks to a few months of consistent supplementation.
How it works
Eurycoma longifolia is believed to exert its effects primarily by stimulating the hypothalamic-pituitary-gonadal (HPG) axis. This stimulation leads to an increased secretion of luteinizing hormone (LH), which in turn promotes testosterone production in the Leydig cells of the testes. The supplement may also contribute to higher levels of free testosterone by reducing sex hormone-binding globulin (SHBG), a protein that binds to testosterone and makes it biologically inactive. The plant contains various bioactive compounds, including quassinoids, which are thought to be responsible for these mechanisms. The absorption and bioavailability of these compounds can vary depending on the extract's standardization, with proprietary extracts often used in studies to ensure consistent bioactive content.
Side effects
Eurycoma longifolia is generally considered safe for use at recommended doses in healthy adults and hypogonadal men. Reported side effects are rare and typically mild, primarily including gastrointestinal discomfort such as nausea or stomach upset, and occasional insomnia. No significant drug interactions or contraindications have been consistently identified in clinical trials, suggesting a relatively low risk profile for short-term use. However, comprehensive long-term safety data are limited, and therefore, caution is advised for prolonged supplementation. Individuals with pre-existing medical conditions, particularly hormone-sensitive cancers or those on hormone-altering medications, should consult a healthcare professional before use. Pregnant or breastfeeding women should avoid Eurycoma longifolia due to insufficient safety data.
Dosage
Effective dosages of Eurycoma longifolia root extract in clinical trials typically range from 200 mg to 400 mg daily. A minimum effective dose for testosterone outcomes appears to be around 200 mg per day. The optimal dosage may vary based on the concentration and standardization of the extract, as well as individual response. It is commonly recommended to take the supplement once or twice daily, often with meals, to potentially enhance absorption. While no specific cofactors are required, using standardized extracts ensures a consistent amount of bioactive compounds. It is important not to exceed recommended dosages, as the safety of higher doses or prolonged use beyond 12 weeks is not well established.
FAQs
Is Eurycoma longifolia safe for long-term use?
Limited long-term safety data exist. Short-term use, typically up to 12 weeks, appears safe based on current research, but caution is advised for prolonged use.
How soon can results be expected from Eurycoma longifolia?
Improvements in testosterone levels are typically observed within 4 to 12 weeks of consistent supplementation, though individual responses may vary.
Does Eurycoma longifolia improve erectile function?
Evidence suggests potential benefits for erectile function, but more high-quality randomized controlled trials are needed to confirm and quantify this effect.
Can women use Eurycoma longifolia?
Most research on Eurycoma longifolia has focused on men. Its safety and efficacy in women are not well established, and it is generally not recommended for female use.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/36013514/ – This systematic review and meta-analysis of five RCTs found a significant increase in total testosterone levels (SMD=1.352) in men supplementing with Eurycoma longifolia, including those with hypogonadism. The study highlights the robust effect size for testosterone enhancement, despite moderate heterogeneity among included trials.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9415500/ – This article, likely a duplicate or related publication to the PubMed entry, further supports the findings of increased total testosterone in men. It emphasizes the clinical relevance of Eurycoma longifolia for testosterone enhancement, particularly in hypogonadal men, based on a meta-analysis of randomized controlled trials.
- https://www.semanticscholar.org/paper/An-Evidence-Based-Systematic-Review-of-Tongkat-Ali-Ulbricht-Conquer/efce2ca8125997cfee4f5e440538d0bc5993d2b6 – This systematic review evaluated various clinical studies on Tongkat Ali, noting improvements in sperm quality and fertility parameters. It reported spontaneous pregnancies in 14.7% of treated men, suggesting clinically meaningful reproductive benefits, though some studies used proprietary extracts and had small sample sizes.
- https://onlinelibrary.wiley.com/doi/10.1155/2022/4999797 – This systematic review, focusing on the antimicrobial properties of Eurycoma longifolia, analyzed 20 in vitro and animal studies. It demonstrated antimicrobial and antiparasitic effects, particularly against E. coli and malaria parasites, but noted the need for clinical validation to confirm these effects in humans.
- https://www.herbalgram.org/resources/herbclip/issues/2016/bin_544/111564-544/ – This systematic review and meta-analysis explored the effects of Eurycoma longifolia on erectile function. It suggested potential improvements in erectile function, but highlighted that effect sizes varied across studies and that more high-quality research with consistent methodologies is needed for definitive conclusions.