Tongkat Ali
Eurycoma longifolia
Southeast-Asian root studied for stress and vitality.
Evidence tier
Preliminary
Research weight
Citations
15 verified / 15
Classification
Adaptogen
❝
What the evidence says. Early or small human trials; promising but not yet conclusive.
What is Tongkat Ali?
Tongkat Ali (Eurycoma longifolia) is an adaptogen used for stress hormone balance. NutriDex grades the human evidence as Preliminary. Tongkat Ali (longjack) is traditionally used for vitality. Small trials report reduced stress hormones and improved tension/wellbeing scores, with some evidence for raised testosterone in deficient or stressed men and improved libido. The literature is small and partly industry-funded, so it remains preliminary. Heavy-metal contamination has been reported in some products — source carefully.
Purported Benefits
✓Stress hormone balance
✓Possible testosterone support
✓Wellbeing
✓Libido
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Serum testosterone5-RCT MA showed significant rise (SMD 1.35), strongest in hypogonadal men; a 2024 RCT in trained adults found no change. | Moderate | ↑ benefit · moderate | 3 |
| Cortisol / stress & moodSmall RCTs report ~16% cortisol drop and improved tension/mood; trials short and partly industry-funded. | Preliminary | ↑ benefit · moderate | 3 |
| Erectile function / libido12-wk Physta RCTs report improved erectile function and ~14% libido gain in men 30-55. | Preliminary | ↑ benefit · moderate | 2 |
| Quality of life / wellbeingRCTs show SF-12/POMS improvements in stressed adults, but several use multi-ingredient formulas. | Preliminary | ↑ benefit · small | 2 |
Dosing & Compounds
Typical Dose
200–400 mg/day standardized extract.
Active Compounds
Safety & Cautions
Limited long-term data. Insomnia, restlessness possible. Source-quality concerns (contaminants). Educational only — always check with your doctor or pharmacist before combining Tongkat Ali with any medicine.
Key Studies ★ 15 studies
meta-analysis
Leisegang 2022 meta-analysis
✓ Full text
Systematic review/meta-analysis of 5 RCTs found Eurycoma longifolia significantly raised serum total testosterone in men (SMD 1.35, 95% CI 0.57-2.14), strongest in hypogonadal subgroups.
Meta-analysis
Leisegang et al. 2022 (meta-analysis of RCTs)
✓ PubMed
Systematic review of 9 studies (5 RCTs in meta-analysis) of Eurycoma longifolia monotherapy in men. Pooled random-effects analysis showed a significant increase in serum total testosterone (SMD = 1.352, 95% CI 0.565 to 2.138, p = 0.001), with the effect confirmed in the hypogonadism subgroup. Concludes E. longifolia is a promising, safe option for enhancing testosterone, particularly in hypogonadal men.
randomized controlled trial
Antonio 2024
✓ Full text
4-week double-blind RCT in 33 exercise-trained men and women found 400 mg/day tongkat ali did NOT change body composition, handgrip strength, mood, sleep, cortisol, or free testosterone versus placebo (null result in already-trained adults).
RCT
BMJ Open 2023
✓ Full text
Registered protocol for a 12-week randomized, double-blind, placebo-controlled trial of standardized water extract (Physta) 50 or 100 mg/day in 150 peri-/postmenopausal women aged 40-55, with mood, quality of life, fatigue, sleep, and reproductive hormone outcomes.
RCT
Sambandan 2021
✓ PubMed
12-week double-blind RCT in 105 ageing men (50-70y) with low testosterone found Physta standardised root extract (100/200 mg/day) increased testosterone and quality of life and lowered cortisol vs placebo.
RCT
Leitao 2021
✓ PubMed
6-month double-blind placebo-controlled RCT in androgen-deficient ageing men found E. longifolia plus concurrent training improved erectile function and raised total testosterone most.
safety review
LiverTox 2024
✓ Full text
NIH LiverTox safety monograph notes isolated reports of clinically apparent liver injury in young men taking tongkat ali, often in multi-ingredient supplements.
randomized controlled trial
George 2016
✓ PubMed
4-week double-blind placebo-controlled RCT in 83 middle-aged Japanese adults found 200 mg/day Physta root extract significantly raised the Scoring of Immunological Vigor and total, naive and CD4+ T-cell counts, indicating enhanced comprehensive immunity vs placebo.
RCT
George et al. 2018 (Physta + multivitamins QoL RCT)
✓ PubMed
24-week randomized, double-blind, placebo-controlled trial in 93 moderately stressed adults (25-65 yr). E. longifolia (Physta) + multivitamins produced within-group improvements in SF-12 quality of life, POMS mood, and a 15% reduction in the physical-stress domain of the MMSQ (vs 0.7% placebo, p<0.05); between-group gains in social functioning (ages 25-45) and POMS-vigour (ages 46-65). Well tolerated.
randomized controlled trial
Ismail 2012 (PHYSTA)
✓ Full text
12-week double-blind RCT in 109 men aged 30-55 found 300 mg/day Physta water extract improved erectile function and sexual libido (~14%), and in men with low baseline values increased semen volume (+18.2%) and sperm motility (+44.4%) vs placebo.
RCT
Talbott et al. 2013 (stress/mood RCT)
✓ PubMed
4-week placebo-controlled trial in 63 moderately stressed adults (32 men, 31 women) on 200 mg/day standardized water extract. Tongkat Ali reduced salivary cortisol (-16%), increased salivary testosterone (+37%), and improved mood: Tension -11%, Anger -12%, Confusion -15% vs placebo.
Review
George 2014 review
✓ PubMed
Promising for male vitality; larger trials needed.
preclinical
Sakai 2024
✓ PubMed
Preclinical study in middle-aged mice found dietary tongkat ali extract enhanced sleep/wake consolidation and diurnal rhythms in wild-type but not narcoleptic mice.
Study
Talbott 2013
✓ Full text
Reduced cortisol and improved mood/stress scores.
Study
Tambi 2012
✓ Source
Improved testosterone in men with late-onset hypogonadism.