Eurycoma longifolia (Tongkat Ali): Effects on Testosterone Levels and Prostate Health - Integrative Function Medicine

An Evidence-Based Overview Eurycoma longifolia (Tongkat Ali): Effects on Testosterone Levels and Prostate Health - Integrative Function Medicine

Edited by Yoon Hang Kim, MD, MPH

Dr. Yoon Hang “John” Kim, a recipient of the 2024 Functional Medicine for All scholarship from the Institute for Functional Medicine, brings over 20 years of experience in integrative and functional medicine to his telemedicine practice. After serving as chief wellness officer at a community hospital in Carthage, IL—where he provided care to rural and underserved populations—Dr. Kim now offers virtual integrative and functional medicine services, making personalized, evidence-based care accessible regardless of location.

His clinical approach integrates functional medicine laboratory testing with complementary therapies, including meditation, yoga, tai chi, and lifestyle interventions that use food and physical activity as medicine to address root causes of disease. Dr. Kim earned his medical degree from the Medical College of Wisconsin, completed a Master of Public Health at San Diego State University, and trained with Dr. Andrew Weil during his residential fellowship at the University of Arizona.

Board-certified by the American Board of Preventive Medicine, the American Board of Medical Acupuncture, and the American Board of Integrative and Holistic Medicine, Dr. Kim has served as a faculty member, consultant, and founder of the Integrative Health Studies Certificate program at the University of West Georgia. His clinical interests include autoimmune disease, chronic pain, integrative oncology, and gastrointestinal disorders. He specializes in complex conditions such as fibromyalgia, chronic fatigue syndrome, long COVID, and toxic mold illness. Dr. Kim has authored two books and more than 20 peer-reviewed and professional articles and has helped establish integrative medicine programs across multiple institutions.

Professional Inquiries: www.yoonhangkim.com

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Introduction

Eurycoma longifolia Jack, commonly known as Tongkat Ali or Longjack, is a traditional Southeast Asian medicinal herb derived from the roots of a shrub native to Malaysia and Indonesia. It has gained increasing scientific interest for its potential to enhance male vitality, primarily through modulation of testosterone levels.

This article reviews the current evidence regarding Eurycoma longifolia’s effects on serum testosterone and prostate health, drawing from randomized controlled trials (RCTs), systematic reviews and meta-analyses, and preclinical studies.

Clinical Evidence on Testosterone Enhancement

A growing body of clinical research supports the ability of Eurycoma longifolia supplementation to increase serum testosterone, particularly in men with hypogonadism or age-related androgen decline. However, interpretation of this evidence requires attention to methodological limitations.

Systematic Review and Meta-Analysis Evidence

A 2022 systematic review and meta-analysis by Leisegang et al. evaluated nine studies, five of which were included in the quantitative meta-analysis. The pooled analysis demonstrated a statistically significant increase in total testosterone, with a standardized mean difference (SMD) of 1.352 (95% CI: 0.565–2.138; p = 0.001).

The effect was most pronounced in hypogonadal men, though benefits were also observed in eugonadal individuals. Subgroup analysis revealed greater improvements among participants with low baseline testosterone levels.

Methodological Considerations

Several important limitations must be acknowledged:

• Publication bias: Begg’s test indicated significant publication bias (p = 0.0243), with additional bias detected in the hypogonadal subgroup using Egger’s and Begg’s tests, suggesting overrepresentation of positive findings.

• Industry involvement: Seven of the nine studies utilized Physta®, a proprietary extract produced by Biotropics Malaysia Berhad. Several trials were industry-funded, and some authors were company employees. While not invalidating the results, this represents a potential conflict of interest.

• Heterogeneity: Substantial heterogeneity was observed across studies (I² = 87.27%), reflecting variability in study populations, dosing, duration, and outcome measures.

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Key Individual Clinical Trials

Chinnappan et al. (2021):A multicenter, double-blind, placebo-controlled RCT involving 105 men aged 50–70 years with baseline testosterone <300 ng/dL found that daily supplementation with 100 mg or 200 mg of a standardized aqueous extract (Physta®) for 12 weeks significantly increased total testosterone. The 200 mg dose produced earlier and stronger effects, with significance observed as early as week 4. Quality-of-life scores also improved. This study was funded by Biotropics Malaysia Berhad, and two authors were company employees.

Leitão et al. (2021):In a six-month RCT involving 45 men with androgen deficiency of aging males (ADAM), 200 mg/day of Eurycoma longifolia combined with concurrent training significantly improved erectile function and increased total testosterone. Approximately 50% of participants demonstrated testosterone increases, with the greatest benefits observed in the combined exercise and supplementation group.

Chan et al. (2021):In a study of 32 healthy young men (mean age 24), supplementation with 600 mg/day for two weeks increased total testosterone by 15% and free testosterone by 34% compared with placebo. Luteinizing hormone and follicle-stimulating hormone levels did not change, suggesting a mechanism independent of direct hypothalamic-pituitary-gonadal axis stimulation. The hypothalamic-pituitary-adrenal axis has been proposed but remains speculative.

Collectively, these studies suggest that doses of 200–600 mg/day of standardized extracts (typically containing 0.8–1.5% eurycomanone) administered for 2–12 weeks may increase testosterone levels, with potential benefits for energy, libido, and muscle strength. Individual response variability remains substantial.

Clinical Evidence on Prostate Health

Direct human clinical evidence evaluating Eurycoma longifolia’s effects on prostate health outcomes—such as benign prostatic hyperplasia (BPH), prostate volume, prostate-specific antigen (PSA), or prostate cancer risk—is limited. No large-scale RCTs have specifically assessed prostate-related endpoints.

Preclinical Evidence

Preclinical findings offer mixed insights. In vitro studies of quassinoids such as eurycomanone demonstrate anti-proliferative and pro-apoptotic effects in prostate cancer cell lines. Tong et al. (2015) reported that a standardized quassinoid composition (SQ40) inhibited LNCaP prostate cancer cell growth via G0/G1 cell cycle arrest, apoptosis induction, reduced androgen receptor translocation, and decreased PSA secretion. In mouse xenograft models, SQ40 significantly suppressed tumor growth.

Animal models of testosterone-induced BPH have shown reduced prostate weight and improved histopathology with certain extracts. However, other rodent studies raise concerns that high doses may induce prostatic epithelial proliferation and dysplastic changes, potentially mediated by elevated testosterone levels.

No human studies have reported increased PSA levels or prostate cancer incidence associated with Eurycoma longifolia use. Nonetheless, due to its androgen-enhancing effects, caution is generally advised in individuals with known prostate disease. Many clinical guidelines contraindicate its use in active prostate cancer.

Safety and Tolerability

Clinical trials report good tolerability at doses ranging from 100–600 mg/day, with no significant adverse effects on liver, kidney, or prostate markers over study durations of 2–24 weeks. Reported side effects have been mild and infrequent, including gastrointestinal discomfort and pruritus.

Long-term safety data in humans remain limited. Medical supervision is recommended for individuals with hormonal sensitivities, prostate disorders, or those taking medications that may interact with androgenic compounds.

Conclusion

Eurycoma longifolia (Tongkat Ali): Effects on Testosterone Levels and Prostate Health - Integrative Function Medicine

Current evidence suggests that Eurycoma longifolia may be an effective natural agent for increasing testosterone levels, supported by multiple RCTs and a recent meta-analysis. However, the evidence base has important limitations, including significant publication bias, substantial industry involvement, high heterogeneity, and relatively small sample sizes.

Its role in prostate health remains unclear. While preclinical data suggest potential anti-cancer activity, theoretical risks related to androgen elevation warrant caution. Well-designed, independently funded, long-term human studies are needed to clarify both efficacy and prostate-specific safety outcomes.

Evidence Quality Assessment

Strengths

• Multiple double-blind, placebo-controlled RCTs

• Statistically significant pooled effect in meta-analysis (SMD = 1.352)

• Consistent testosterone increases in hypogonadal and eugonadal men

• Favorable short-term safety profile

Limitations

• Significant publication bias (p = 0.0243)

• Heavy reliance on a single proprietary extract

• High inter-study heterogeneity (I² = 87.27%)

• Limited long-term safety data

• Absence of large prostate-specific clinical trials

At Direct Integrative Care, Dr. Kim provides personalized, patient-centered integrative medicine focused on identifying root causes and restoring balance. Through compassionate care and evidence-based therapies, patients are empowered with the knowledge and tools needed for sustainable health and vitality.

Yoon Hang Kim, MDIntegrative & Functional Medicine PhysicianVirtual Practice Serving IA, IL, MO, FL, GA, and TXwww.directintegrativecare.com

References

References

Chan, K. Q., Stewart, C., Chester, N., Hamzah, S. H., & Yusof, A. (2021). The effect of Eurycoma longifolia on the regulation of reproductive hormones in young males. Andrologia, 53(4), e14001. https://doi.org/10.1111/and.14001

Chinnappan, S. M., George, A., Pandey, P., Narke, G., & Choudhary, Y. K. (2021). Effect of Eurycoma longifolia standardised aqueous root extract–Physta® on testosterone levels and quality of life in ageing male subjects: A randomised, double-blind, placebo-controlled multicentre study. Food & Nutrition Research, 65, Article 5647. https://doi.org/10.29219/fnr.v65.5647

Leitão, A. E., Vieira, M. C. S., Pelegrini, A., da Silva, E. L., & Guimarães, A. C. A. (2021). A 6-month, double-blind, placebo-controlled, randomized trial to evaluate the effect of Eurycoma longifolia (Tongkat Ali) and concurrent training on erectile function and testosterone levels in androgen deficiency of aging males (ADAM). Maturitas, 145, 78–85. https://doi.org/10.1016/j.maturitas.2020.12.002

Leisegang, K., Finelli, R., Sikka, S. C., & Panner Selvam, M. K. (2022). Eurycoma longifolia (Jack) improves serum total testosterone in men: A systematic review and meta-analysis of clinical trials. Medicina, 58(8), Article 1047. https://doi.org/10.3390/medicina58081047

Tong, K. L., Chan, K. L., AbuBakar, S., Low, B. S., Ma, H. Q., & Wong, P. F. (2015). The in vitro and in vivo anti-cancer activities of a standardized quassinoids composition from Eurycoma longifolia on LNCaP human prostate cancer cells. PLOS ONE, 10(3), e0121752. https://doi.org/10.1371/journal.pone.0121752