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Eurycoma Longifolia Jack

Also known as: Tongkat Ali, Malaysian ginseng, Longjack, Eurycoma longifolia Jack

Overview

Eurycoma longifolia Jack, commonly known as Tongkat Ali, is a medicinal plant native to Southeast Asia. It is widely recognized as a traditional herbal supplement primarily used to enhance male sexual health and vitality. Its main applications include boosting testosterone levels and improving sexual function, particularly in cases of erectile dysfunction and low libido. The plant's therapeutic effects are attributed to its bioactive compounds, notably quassinoids like eurycomanone. Research on Eurycoma longifolia is moderately mature, with several randomized controlled trials and at least one systematic review and meta-analysis supporting its efficacy in testosterone enhancement. While the quality of evidence is emerging, some limitations exist due to small sample sizes and heterogeneity across studies. It is available in various forms, typically as standardized extracts.

Benefits

The primary and most robustly supported benefit of Eurycoma longifolia is its ability to significantly increase serum total testosterone levels in men, including those diagnosed with hypogonadism (low testosterone). A meta-analysis of five randomized controlled trials demonstrated a standardized mean difference (SMD) of 1.352 (95% CI 0.565 to 2.138, p = 0.001), indicating a moderate to large effect size on testosterone levels. This effect has been observed in both healthy individuals and men with pre-existing low testosterone. Secondary benefits include reported improvements in erectile function and overall sexual well-being. While promising, the evidence for these secondary effects is less robust and warrants further high-quality research. Benefits typically manifest after several weeks to a few months of consistent supplementation. The strength of evidence for testosterone increase is considered moderate, based on systematic reviews and meta-analyses, while evidence for sexual function improvements is still emerging.

How it works

Eurycoma longifolia is believed to exert its effects primarily by stimulating the hypothalamic-pituitary-gonadal (HPG) axis. This stimulation leads to increased secretion of luteinizing hormone (LH), which in turn prompts the Leydig cells in the testes to produce more testosterone. Additionally, the bioactive quassinoids present in Eurycoma longifolia may inhibit the aromatase enzyme, thereby reducing the conversion of testosterone into estrogen. This inhibition helps to maintain higher levels of free, active testosterone in the body. The supplement may also contribute to testosterone optimization through anti-stress effects, potentially reducing cortisol levels, which can otherwise suppress testosterone production. The oral bioavailability of key compounds like eurycomanone is moderate, and standardized extracts are preferred for consistent efficacy.

Side effects

Eurycoma longifolia is generally considered safe, with a low incidence of adverse effects reported in clinical trials. Specific common side effects (occurring in >5% of users) are not well-documented, but mild gastrointestinal discomfort has been anecdotally reported. Uncommon or rare side effects have not been clearly identified in high-quality studies. No major drug interactions have been conclusively established; however, caution is advised when combining Eurycoma longifolia with hormone therapies or anticoagulant medications due to potential additive effects. Contraindications are not well-defined, but prudence is recommended for individuals with hormone-sensitive conditions or pre-existing prostate disorders. There is insufficient safety data for special populations, including women, children, and pregnant or breastfeeding individuals, therefore its use is not recommended in these groups.

Dosage

Effective dosages of Eurycoma longifolia in clinical trials typically range from 200 mg to 400 mg of a standardized extract daily. While a minimum effective dose is not firmly established, 200 mg per day is a commonly used starting point. Doses up to 400 mg per day have been administered in studies without serious adverse effects, suggesting this as a safe upper limit for short to medium-term use. The maximum safe dose for long-term use is not yet well-defined. For optimal absorption and consistency, daily administration is recommended, often taken with meals. It is crucial to use standardized extracts that specify the content of bioactive compounds, such as eurycomanone, to ensure consistent potency and efficacy.

FAQs

Is Tongkat Ali safe?

Tongkat Ali is generally considered safe for most healthy adults at recommended doses. However, long-term safety data are limited, and it's not recommended for women, children, or those with hormone-sensitive conditions.

How soon do effects appear?

Increases in testosterone levels are typically observed within 4 to 12 weeks of consistent supplementation. Other benefits, such as improvements in sexual function, may also become noticeable within this timeframe.

Does it improve erectile dysfunction?

Some evidence suggests that Tongkat Ali may improve erectile function and sexual well-being. However, more high-quality, large-scale clinical trials are needed to confirm these benefits definitively.

Can women use it?

Tongkat Ali has primarily been studied in men for its effects on testosterone and male sexual health. There is insufficient evidence regarding its safety and efficacy in women, and its use is generally not recommended for them.

Research Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC9415500/ – This systematic review and meta-analysis of randomized controlled trials (RCTs) investigated the effect of Eurycoma longifolia Jack on serum total testosterone in men. It found a significant increase in total testosterone levels, particularly in men with hypogonadism, with a standardized mean difference of 1.352. The study highlights the potential of E. longifolia as a testosterone booster, despite some heterogeneity among the included studies.
https://pubmed.ncbi.nlm.nih.gov/36013514/ – This publication is likely a duplicate or closely related entry to the PMC link, also detailing the systematic review and meta-analysis by Leisegang et al. (2022). It confirms the significant increase in total testosterone levels in men, including those with hypogonadism, supporting Eurycoma longifolia's role in male hormonal health.
https://clinicaltrials.gov/study/NCT05347329 – This entry describes an ongoing or recently completed Phase II randomized controlled trial evaluating the efficacy of Eurycoma longifolia in men aged 35–65 with mild to moderate erectile dysfunction. The study aims to assess its impact on erectile function and sexual well-being, with results pending publication. This trial represents current research efforts to further validate secondary benefits.
https://www.semanticscholar.org/paper/An-Evidence-Based-Systematic-Review-of-Tongkat-Ali-Ulbricht-Conquer/efce2ca8125997cfee4f5e440538d0bc5993d2b6 – This systematic review by Ulbricht et al. (2014) examined various health claims of Tongkat Ali, including its effects on erectile function. It concluded that while some evidence suggests improvements in erectile function with E. longifolia supplementation, the number of high-quality randomized controlled trials was limited at the time, indicating a need for further research.
https://engage.tulane.edu/publications/eurycoma-longifolia-jack-improves-serum-total-testosterone-in-men-a-systematic-review-and-meta-analysis-of-clinical-trials/ – This publication from Tulane University's 'Engage' platform is another instance of the systematic review and meta-analysis by Leisegang et al. (2022). It reiterates the key finding that Eurycoma longifolia Jack significantly improves serum total testosterone in men, based on a comprehensive analysis of clinical trials, reinforcing the evidence for its primary benefit.