CoChat
Sign Up
Cited by 13Hormonal and reproductive studiesPhytochemicals and Medicinal PlantsSperm and Testicular Function

The effect of Eurycoma Longifolia on the regulation of reproductive hormones in young males

Open access
Chan, Kai Quin, Stewart, Claire, Chester, Neil, Hamzah, Sareena H., Yusof, Ashril·2021·Andrologia
DOI 10.1111/and.14001
Open this paper in CoChat — free accountOpen PDF

Abstract

Eurycoma longifolia supplementation increases testosterone levels in humans via activation of the hypothalamic-pituitary-gonadal axis and/or the hypothalamic-pituitary-adrenal axis mainly in older adults and nonhealthy populations. This study aimed to assess the impact of Eurycoma longifolia on the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal axes in healthy young males since this might promote functional testosterone prowess. Thirty-two males (24.4 ± 4.7 years; 1.74 ± 0.07 m; 73.7 ± 8.4 kg) in a placebo-controlled, double-blind, matched-paired study received 600 mg/day Eurycoma longifolia or placebo for two weeks. Blood analysis using repeated measures analysis of variance showed significant interaction and time effects for testosterone (F1,30 = 9.04, p = .005), free testosterone (F1,30 = 7.13, p = .012) and estradiol (F1,30 = 8.07, p = .008) levels in favour of the treatment group, while luteinising hormone, follicle-stimulating hormone and sexual hormone-binding globulin did not. The lack of changes in luteinising hormone and follicle-stimulating hormone levels suggests that a lesser role played by Eurycoma longifolia in activating the hypothalamic-pituitary-gonadal axis in the young adults. The raised testosterone level may be due to a greater rate of hormone production via the hypothalamic-pituitary-adrenal axis. The supplementation of Eurycoma longifolia for two weeks demonstrates steroidogenic effects on young men were dose-related. Consequently, the raised testosterone following Eurycoma longifolia supplementations could benefit muscle and strength gain in young adults.

Integrity signals

Registry

Crossref · 10.1111/and.14001

Cites

51 of 51 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 35 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    LH, FSH, and SHBG analyses did not reveal any differences between or within group effects.

    “Meanwhile, LH, FSH and SHBG analyses did not reveal any differences between and within group effects.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Free testosterone was 34% higher at post-intervention in the Eurycoma longifolia group.

    “where free testosterone was observed 34% higher at post-intervention in EL.”
    Quote in the paperSubstantial claim
  • Findingcitation

    The rise in estradiol observed in this study is still within the normal range of 10 to 82 pg/ml in men.

    “However, the rise in estradiol observed in this study is still within the normal range of 10-82 pg/ml in men (Yamamoto et al., 1995).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Yamamoto et al., 1995

      Not checked in the free run.

  • Findingown data

    Estradiol was 30% higher at post-intervention in the Eurycoma longifolia group.

    “where estradiol was observed 30% higher at post-intervention in EL.”
    Quote in the paperSubstantial claim
  • Findingown data

    Testosterone level was 15% higher in the Eurycoma longifolia group after two weeks of consumption.

    “Testosterone level was 15% higher in EL following two weeks of consumption.”
    Quote in the paperSubstantial claim
  • May combine two claims. 22
  • Classified as probably not a substantial claim. 7
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingown data

    There was a significant group-by-time interaction for testosterone (F 1,30 = 9.039, p = .005), as well as significant group and time main effects.

    “There was a significant interaction between group and time for testosterone (F 1, 30 = 9.039, p = .005),as well as group (F 1, 30 = 4.01, p = .05)and time (F 1, 30 = 4.36, p = .04)main effects.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The present study shows that 600 mg/day of Eurycoma longifolia increases testosterone, free testosterone, and estradiol levels among young adult men.

    “In summary, the present study shows that 600 mg/day of EL increases testosterone, free testosterone and estradiol levels among young adult men.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    There was a significant group-by-time interaction for free testosterone (F 1,30 = 7.13, p = .012) and a significant time main effect (F 1,30 = 11.73, p = .002).

    “While for free testosterone, there was a significant main interaction between group and time (F 1, 30 = 7.13, p = .012),as well as time main effect (F 1, 30 = 11.73,p = .002)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In the current study, two weeks of 600 mg Eurycoma longifolia supplementation alone raised testosterone to 9.24 ng/mL, slightly above the normal human range of 2.64 to 9.16 ng/mL.

    “In the current study, 2 weeks of EL supplementation (600 mg) alone (without strength training) raised the testosterone level (9.24 ng/mL) slightly above the normal human range (2.64-9.16ng/mL) as described by Travison et al. (2017).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Travison et al., 2017

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    There was a significant group-by-time interaction for estradiol (F 1,30 = 8.07, p = .008) and a significant time main effect (F 1,30 = 4.22, p = .04).

    “As for estradiol, there was a significant interaction between group and time (F 1, 30 = 8.07, p = .008),as well as time main effect (F 1, 30 = 4.22, p = .04)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Eurycoma longifolia supplementation raises testosterone in humans through activation of the hypothalamic-pituitary-gonadal and/or hypothalamic-pituitary-adrenal axes, mainly in older adults and nonhealthy populations.

    “Eurycoma longifolia supplementation increases testosterone levels in humans via activation of the hypothalamic-pituitary-gonadal axis and/or the hypothalamic-pituitaryadrenal axis mainly in older adults and nonhealthy populations.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Chen et al., 2014

      Not checked in the free run.

    • cites Henkel et al., 2014

      Not checked in the free run.

    • cites Ismail et al., 2012 source

      Not checked in the free run.

    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • May combine two claims.

    Premisecitation

    Bioactive compounds in Eurycoma longifolia, including eurycomanone, alleviate sexual dysfunction and hypogonadism in older adults.

    “The increase in testosterone levels is attributed to the synergistic effect of bioactive compounds in EL (including eurycomanone), which demonstrate the ability to alleviate sexual dysfunction and hypogonadism among older adults”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Bhat & Karim, 2010

      Not checked in the free run.

    • cites Ismail et al., 2012 source

      Not checked in the free run.

    • cites Kotirum et al., 2015

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Bioactive compounds in Eurycoma longifolia enhance testosterone steroidogenesis and improve fertility in rats.

    “or enhance testosterone steroidogenesis and improve fertility in rats (Low et al., 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Low et al., 2013

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Eurycoma longifolia alone restores testosterone levels in older adults, those with late-onset hypogonadism, hypertension, diabetes, and moderately stressed individuals.

    “Apart from exercise stimulus, consuming EL alone has been shown to be effective in restoring testosterone levels in older adults (Henkel et al., 2014;Talbott et al., 2013;Tambi et al., 2012;Udani et al., 2014) and those with late-onset hypogonadism (LOH) (Tambi et al., 2012), hypertension and diabetes (Henkel et al., 2014) as well as individuals that are moderately stressed (Talbott et al., 2013).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Henkel et al., 2014

      Not checked in the free run.

    • cites Talbott et al., 2013

      Not checked in the free run.

    • cites Tambi et al., 2012

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    At baseline, there were no significant differences in age, body weight, body fat percentage, and lean body mass between the Eurycoma longifolia and placebo groups.

    “At baseline, there were no significant differences in age, body weight, body fat percentage and lean body mass between EL and PLA groups (p > .05).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The higher estradiol and testosterone levels suggest that Eurycoma longifolia may not inhibit the aromatase enzyme, contrary to previous suggestions.

    “The higher estradiol and testosterone levels reported suggest that EL may not inhibit the aromatase enzyme.”
    • Also stated in: § TA B L E 1 · hedged
      “Meanwhile, contrary to previous suggestions the increase in estradiol suggests that the aromatase may not be inhibited.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The raised testosterone level may be due to greater hormone production via the HPA axis, possibly through direct adrenal stimulation producing testosterone precursors.

    “The raised testosterone level may be due to a greater rate of hormone production via the hypothalamicpituitary-adrenal axis.”
    • Also stated in: § TA B L E 1 · hedged
      “it is plausible that the increase of testosterone could be due to direct stimulation of the adrenal gland in the HPA axis (Talbott et al., 2006) to produce testosterone precursors”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Talbott et al., 2006

      Not checked in the free run.

    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • May combine two claims. The quote only partly states this claim.

    Interpretationown data

    The lack of changes in LH and FSH suggests a lesser role of Eurycoma longifolia in activating the HPG axis in young adults, leaving its impact on this axis unclear.

    “The lack of changes in luteinising hormone and follicle-stimulating hormone levels suggests that a lesser role played by Eurycoma longifolia in activating the hypothalamic-pituitary-gonadal axis in the young adults.”
    • Also stated in: § 4 | D ISCUSS I ON · hedged
      “The lack of changes in LH, FSH and SHBG levels suggests a lesser effect of EL on HPG axis after two weeks of supplementation.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    Statistical assumptions of normality, homogeneity of variances, compound symmetry, and homogeneity of regression were checked and fulfilled.

    “Assumptions of normality, homogeneity of variances, compound symmetry, and homogeneity of regression were checked and fulfilled.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductown data

    The study used a placebo-controlled, double-blind, body weight matched-pairs design.

    “The study is a placebo-controlled, double-blind, body weight matched-pairs design where participants were allocated into two groups: E. longifolia group (EL) (n = 16) and placebo group (PLA) (n = 16).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Adherence to the protocol was assessed using a dietary recall diary and text message reminders.

    “Participants' adherence to the protocol was assessed using the dietary recall diary where time they took the supplement and how they felt at different times during the day were recorded.Additionally, reminders were sent out via text messages to ensure compliance.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Two weeks of 600 mg/day Eurycoma longifolia supplementation demonstrates dose-related steroidogenic effects on young men, increasing testosterone compared with previous lower-dose studies.

    “The supplementation of Eurycoma longifolia for two weeks demonstrates steroidogenic effects on young men were dose-related.”
    • Also stated in: § 4 | D ISCUSS I ON · boosted
      “The dosage of 600 mg EL (8.7 mg of eurycomanone) used in the current study increased testosterone level in young males (18-30 years) and demonstrates the steroidogenic effects of the herb on young males were dose-related when compared with previous studies”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Chen et al., 2014

      Not checked in the free run.

    • cites Chen et al., 2019

      Not checked in the free run.

    • cites Henkel et al., 2014

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Eurycoma longifolia is known to contain active flavonoids and quassinoids, which could potentially increase testosterone via the HPG and HPA axes by converting testosterone precursors.

    “EL is known to have active flavonoids (Bashir et al., 2017;Khanam et al., 2014) and quassinoids (Darise et al., 1982;Miyake et al., 2009;Tung et al., 2017), which could potentially increase testosterone levels via the HPG and as well via the HPA axis by converting the testosterone precursors.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Bashir et al., 2017

      Not checked in the free run.

    • cites Khanam et al., 2014

      Not checked in the free run.

    • cites Darise et al., 1982

      Not checked in the free run.

    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • May combine two claims.

    Premisecitation

    Stimulation of the HPA axis increases cortisol production, which reduces HPG activity.

    “Meanwhile, stimulation of the HPA axis in general increases cortisol production, which reduces HPG activity (Chen et al., 1997;Sherman et al., 2016;Viau, 2002).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Chen et al., 1997

      Not checked in the free run.

    • cites Sherman et al., 2016

      Not checked in the free run.

    • cites Viau, 2002

      Not checked in the free run.

    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • May combine two claims.

    Study design and conductown data

    The Eurycoma longifolia extract used was a single batch of Physta water extract with eurycomanone content of 1.45% w/v, complying with the Malaysian Standard.

    “The EL used in the present study complied with the standard since eurycomanone content was 1.45 w/v (%).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Malaysian Standard (2011)

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    A plausible alternative explanation for the increase in testosterone is direct stimulation of the adrenal gland in the HPA axis converting testosterone precursors to testosterone, not entirely from HPG axis activation.

    “A plausible alternative explanation on the increase in testosterone could be due to the direct stimulation of the adrenal gland in the HPA axis converting testosterone precursor to testosterone and not entirely from the activation of the HPG axis.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

  • Classified as probably not a substantial claim.

    Premisecitation

    In animals, eurycomanone-induced testosterone increases are attributed to elevated LH and FSH stimulating Leydig cells to produce testosterone.

    “It has been proposed that, in animals, the increased testosterone levels when given eurycomanone could be attributed to elevated gonadotropins, luteinising hormone (LH) and follicle-stimulating hormone (FSH) that stimulate the Leydig cells to produce testosterone (Low et al., 2013)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Low et al., 2013

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    All participants complied with supplementation (100% compliance) and no adverse effects were reported.

    “All participants complied with the supplementation (100% compliance), and no adverse effects were reported.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Administration of an increased Eurycoma longifolia dosage of 600 mg/day for two weeks can increase testosterone in young male participants and could potentially have a positive impact on sports performance.

    “Hence, administration of an increased dosage of EL (600 mg/day) for two weeks can increase the testosterone level among young male participants and therefore could potentially have a positive impact on sports performance.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Eurycoma longifolia extract lowers cortisol and raises testosterone through conversion of testosterone precursors in the HPA axis.

    “However, it is suggested that EL extract lowers cortisol and increases testosterone levels through the conversion of testosterone precursors in the HPA axis (Talbott et al., 2006(Talbott et al., , 2013)).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Talbott et al., 2006

      Not checked in the free run.

    • cites Talbott et al., 2013

      Not checked in the free run.

    • Rests on an assumption: Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.
25 of 25

  • The paper relies on this without support.

    Testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.

    “Physiologically, testosterone levels in the body are regulated predominantly via the HPG axis and to a lesser extent the HPA axis.”

  • The paper relies on this without support.

    Research examining the effect of Eurycoma longifolia extract on HPG and HPA axis activation in a young adult population is scarce.

    “However, research examining the effect of EL extract (standardised to eurycomanone content) on the activation of the HPG and HPA axis in a young adult population is scarce.”
2 of 2

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The increase in testosterone after E. longifolia has been found to be associated with an effect on the HPA.

    “The increase in testosterone has been found to be associated with an effect on the HPA.[Citation85]”

    From Ergogenic properties, safety evaluation and regulations of selected ingredients in testosterone booster dietary supplements (2024) · cites this paper as [85]

    The study’s summary reports increased testosterone after E. longifolia supplementation in young men. It describes an HPA-axis pathway as a plausible explanation, not an established association: the discussion says the proposed mechanisms need further investigation, and the study did not establish an effect on the HPA axis. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Application of 600 mg of E. longifolia extract (standard eurycomanone 1.45%) each day for 2 weeks increased testosterone, free testosterone, and estradiol levels among young men aged 24.4 ± 4.7 years.

    “The application of 600 mg of E. longifolia extract (standard is eurycomanone 1.45%) each day for 2 weeks contributed to increased testosterone, free testosterone, and estradiol levels among young men (age 24.4 ± 4.7 years).”

    From Ergogenic properties, safety evaluation and regulations of selected ingredients in testosterone booster dietary supplements (2024) · cites this paper as [85]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Placebo estradiol confidence interval excludes its mean change

    Major

    The placebo estradiol means imply a pre-minus-post change of −10.77 pg/mL, but the reported confidence interval for the difference runs from −7.56 to 12.23 pg/mL. An interval for that difference cannot exclude its own point estimate.

  • Placebo FSH interval is centered on a different change

    Minor

    The placebo FSH means imply a pre-minus-post change of −0.14 mIU/mL, while the reported confidence interval is centered at 0.78 mIU/mL. These do not describe the same estimated difference.

2 of 2

Cites

Flagged first, then by citations

1 of the 52 references couldn’t be matched to a known paper.

Research works printed but not linked: 5

  1. Khanam Z., 2014, Phytochemical analyses and DNA cleavage activity of Citrus maxima fruit
  2. Malaysian Standard, 2011, Phytopharmaceutical aspects of freeze dried water extract from Tongkat Ali roots‐specification, 12
  3. Prakash G., 2007, Reproductive biology, 12.8
  4. Talbott S., 2006, Effect of eurycoma longifolia extract on anabolic balance during endurance exercise [abstract], Journal of International Society Sports Nutrition, 3, S32
  5. Tambi M. I. M., 2005, Standardised water‐soluble extract of Eurycoma longifolia (LJ100) on men's health, International Journal of Andrology, 28, 27

Cited by

Sorted by citations

Related

Authors
Chan, K. Q., Stewart, C., Chester, N., Hamzah, S. H., & Yusof, A.
Affiliations
  • University of Malaya (MY)
  • Liverpool John Moores University (GB)
Corresponding author
Yusof, Ashril
ORCID
Venue
Andrologia
Publisher
Wiley
Published
2021-02-09
Volume
53
Issue
4
Pages
e14001-e14001
ISSN
  • 0303-4569 (ISSN-L)
  • 1439-0272
DOI
10.1111/and.14001
OpenAlex
W3127473645
Semantic Scholar
ff0dbaf6f8da26786d24ea7cb4feb4c72b3a2c9a
Cited by
12
References
52
Citations by year
2026: 2 · 2024: 3 · 2023: 4 · 2022: 2 · 2021: 1
FWCI
1.86
Type
journal article
Language
en
Open access
Licence
Locations
  • Andrologia (publishedVersion)
  • PubMed (publishedVersion)
  • Liverpool John Moores University (acceptedVersion)
Funders
Universiti Malaya
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Complementary and alternative medicine › Phytochemicals and Medicinal Plants
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
Keywords
Eurycoma longifolia, testosterone, reproductive hormones, hypothalamic-pituitary-gonadal axis, hypothalamic-pituitary-adrenal axis, estradiol, free testosterone, luteinizing hormone, follicle-stimulating hormone, young men, herbal supplementation
MeSH terms
Aged, Double-Blind Method, Humans, Hypothalamo-Hypophyseal System, Male, Pituitary-Adrenal System, Plant Extracts, Testosterone, Eurycoma, Young Adult

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-07.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-07.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review