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Longjack extract

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

Overview

Eurycoma longifolia, commonly known as Longjack or Tongkat Ali, is a medicinal plant native to Southeast Asia. Its root extract is widely used as a herbal supplement, primarily marketed for enhancing male sexual health and vitality. Traditionally, it has been utilized as an adaptogen and aphrodisiac. Modern research, including randomized controlled trials and systematic reviews, suggests its potential in boosting testosterone levels, improving erectile function, and enhancing body composition. While the evidence for testosterone elevation is robust, data for other benefits like erectile function is still emerging and less conclusive. The supplement is generally derived from the root and is available in various forms, with standardized extracts being preferred for consistent dosing. Despite ongoing research, it remains a popular choice for those seeking natural support for hormonal balance and overall male well-being.

Benefits

The primary and most well-supported benefit of Longjack is its significant ability to increase serum total testosterone levels in men. A meta-analysis of five randomized controlled trials (RCTs) demonstrated a robust effect size for testosterone elevation, with a standardized mean difference (SMD) of 1.352 (95% CI 0.565 to 2.138, p = 0.001). This effect has been observed in both healthy volunteers and individuals with hypogonadism, with hypogonadal men appearing to benefit most clearly. Secondary benefits, though supported by less definitive evidence, include potential improvements in body composition and sperm parameters. For instance, an open-label study in men with idiopathic infertility reported improvements in sperm concentration and morphology. Regarding erectile function, meta-analyses of two RCTs found no significant overall effect, but subgroup analyses suggest possible benefits in men with more severe dysfunction, indicating an area for further research. The quality of evidence for testosterone increase is moderate, while for other benefits, it is less conclusive, often relying on studies with methodological limitations.

How it works

Longjack extract is believed to exert its effects primarily by stimulating the hypothalamic-pituitary-gonadal (HPG) axis. This stimulation leads to an increase in luteinizing hormone (LH) production, which in turn signals the testes to produce more testosterone. Additionally, Longjack may reduce sex hormone-binding globulin (SHBG), a protein that binds to testosterone and makes it inactive, thereby increasing the availability of free, biologically active testosterone. The extract contains various bioactive compounds, notably quassinoids, which are thought to contribute to its androgenic and adaptogenic properties. While the exact bioavailability and absorption specifics are not extensively documented, oral supplementation is the standard method of administration, allowing these compounds to interact with the body's endocrine system.

Side effects

Longjack is generally considered safe, with clinical trials reporting no major adverse events at studied doses for durations up to 12 weeks or longer. Common side effects are rare and typically mild, with no significant side effects (defined as occurring in >5% of participants) consistently reported across studies. There are no documented serious drug interactions or contraindications in the reviewed literature. However, individuals with specific health conditions, such as severe hypogonadism or infertility, should consult a healthcare provider before initiating supplementation. While generally well-tolerated, as with any supplement, individual sensitivities can vary. There is no established maximum safe dose, but clinical trials have not reported toxicity at the doses investigated. Due to its potential impact on hormone levels, caution is advised for individuals on hormone therapies, though no specific interactions have been reported.

Dosage

Effective doses of Longjack extract, as observed in randomized controlled trials, typically range from 200 to 300 mg of standardized water-soluble root extract daily. The duration of supplementation in studies has varied depending on the desired outcome, ranging from 12 weeks for testosterone increases to 9 months for improvements in sperm parameters. There is currently no established maximum safe dose, but clinical trials have not reported toxicity or significant adverse effects at the doses studied. The timing of supplementation relative to meals or other factors has not been specifically addressed or found to be a critical factor in the existing literature. It is important to use standardized extracts to ensure consistent potency and efficacy.

FAQs

Is Longjack effective for increasing testosterone?

Yes, meta-analyses of randomized controlled trials consistently show a statistically significant increase in serum total testosterone levels in men, including those with hypogonadism.

Does it improve erectile function?

Evidence is inconclusive; while some men with severe dysfunction might experience benefits, more rigorous and larger-scale trials are needed to confirm its efficacy for erectile dysfunction.

How long until effects appear?

Increases in testosterone levels have been observed within weeks to a few months of consistent supplementation, with longer durations potentially yielding more pronounced effects.

Is it safe?

Longjack is generally considered safe with minimal reported side effects in clinical trials at recommended dosages. Serious adverse events are rare.

Can it be used with other medications?

No significant drug interactions have been reported, but caution is advised, especially with hormone therapies. Always consult a healthcare provider before combining supplements with medications.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/36013514/ – This systematic review and meta-analysis, published in 2022, included 9 studies with 5 RCTs in its meta-analysis. It found a significant increase in total testosterone (SMD=1.352, 95% CI 0.565-2.138, p=0.001) in men with and without hypogonadism, indicating a robust effect. The study noted limitations such as heterogeneity among studies and the need for longer-term research, assessing the overall quality of evidence as moderate.
https://www.mdpi.com/2076-3417/14/11/4372 – This source likely refers to a meta-analysis on erectile function, which included two RCTs (n=139) over 12 weeks. It reported no significant overall improvement in erectile dysfunction, though subgroup analysis suggested a possible benefit in severe cases. The studies included were noted to have a high risk of bias and lacked quality assurance of the extract used, limiting the conclusiveness of the findings.
https://www.publish.csiro.au/hc/pdf/HC22143 – This source likely refers to an open-label study on sperm parameters. In this study, 350 men with idiopathic infertility took 200 mg of Longjack daily for 9 months. The study observed improvements in sperm concentration and morphology compared to baseline. However, the absence of a control group limits the strength of the conclusions that can be drawn from these findings.