Tongkat Ali
EVIDENCE: MODERATEAlso sold as: Eurycoma longifolia, longjack, Malaysian ginseng, LJ100
Standardized tongkat ali extracts have human trials showing modest testosterone changes and reduced cortisol at 200–400 mg daily. The extract and amount matter when comparing other preparations with those findings.
Compiled by iSupplementReviews editorial team ·Updated 2026-10-13 · 5 sources
- Type
- Botanical root extract
- Studied dose
- 200–400 mg/day (standardized root extract)
- Best form
- standardized extract (LJ100 or stated eurycomanone %) at a real ratio like 100:1 or 200:1
- Our rating
- MODERATE — Several human trials — limits in size, duration, or independence
What is tongkat ali?
Tongkat ali (Eurycoma longifolia) is a Southeast Asian shrub whose bitter root has traditional male-vitality uses. Compounds including eurycomanone and eurycomanol have proposed hormone and stress effects, followed by human trials of standardized extracts.
The forms that matter
| Form | What it is | Notes |
|---|---|---|
| LJ100 | Patented hot-water extract, standardized | The trial standard |
| Ratio extracts (100:1, 200:1) | Root condensed at stated ratio | Quality signal — but ratio ≠ standardization |
| Eurycomanone-standardized | Stated active % | The technical gold standard |
| Root powder | Unextracted | Weakest form — trials used extracts |
Where does it come from?
Malaysia and Indonesia: the root comes from slow-growing jungle shrubs, which is why real extract costs money and adulteration is rampant in the supply chain.
How does tongkat ali work in the body?
Two levers, both plausible: quassinoids appear to stimulate testicular steroid production (enzyme-level effects, mostly animal/lab evidence), and human data shows cortisol reduction under stress (Talbott 2013: cortisol −16%, testosterone +37% in moderately stressed adults). A mild SHBG effect may free additional bound testosterone.
What is tongkat ali claimed to do?
Raise testosterone, improve libido and erectile function, reduce stress, support muscle and strength: the full male-vitality stack.
What does the research show?
| Claim | Evidence | Dose studied | Verdict |
|---|---|---|---|
| Testosterone in low/stressed men | Trials + systematic review | 200–400 mg/day | Supported, modest |
| Cortisol/stress reduction | Trial (Talbott 2013) | 200 mg/day | Supported |
| Erectile function/QoL | Small trial (Ismail 2012, n=109) | 300 mg/day | Early positive |
| Libido | Small trials | 200–400 mg/day | Early positive |
| Muscle/strength | Few trials, mixed | 400 mg/day | Weak |
Testosterone — the headline trial
Henkel et al. (2014, Andrologia): 76 men with late-onset low testosterone on 200–400 mg/day saw testosterone rise significantly, and the share of men reaching normal testosterone climbed from ~36% to ~91% in one month. Caveats: men selected for low T (where any effect shows biggest), Malaysian-linked research, and one month is short.
Stress and cortisol — the second solid finding
Talbott et al. (2013, JISSN): 63 moderately stressed adults, 200 mg/day for 4 weeks: cortisol −16%, testosterone +37%, with tension/anger/confusion scores all improving. It frames tongkat as much an anti-stress agent as a T agent; the two are probably one mechanism.
The systematic verdict
Leitão et al. (2021) reviewed the trial base: tongkat reliably raises testosterone in men with low baseline or high stress, with standing calls for larger, independent trials. That’s an “supported, modest”: real effects, small literature.
What doesn’t tongkat ali do?
It doesn’t produce prescription-scale hormone changes, doesn’t help men with already-optimal testosterone much, and a ratio claim without standardization guarantees nothing about what’s in the capsule.
What dose was studied?
| Goal | Dose | Form | Duration |
|---|---|---|---|
| Testosterone (low-T men) | 200–400 mg | standardized extract | 1–3 months |
| Stress/cortisol | 200 mg | standardized extract | 4 weeks |
| Erectile function | 300 mg | extract | 12 weeks |
200–400 mg/day of real extract, and “real extract” does the heavy lifting: 100 mg of even a 100:1 extract sits under the positive-trial floor.
How and when to take it
Morning dosing (it can be mildly stimulating); trials run continuously for 4–12 weeks. Some practitioners suggest 5-days-on/2-off cycling: convention, not trial-tested.
Side effects
Insomnia, restlessness, irritability, mostly high-dose or evening-dosed. Mild and dose-dependent. The bigger hazard is supply-chain contamination: regulators have flagged tongkat products spiked with heavy metals or undeclared drug analogs, which is a buying-quality problem, not a plant problem.
Drug interactions
Limited formal data: theoretical additive effects with hormone therapies; caution combining with stimulants (the insomnia effect compounds). The adulteration history is the more concrete interaction-adjacent risk.
Who should not take tongkat ali?
Men on hormone therapy without medical oversight, insomnia-prone users (dose mornings only), and anyone whose only source is an unverified brand.
What the authorities say
There’s no NIH fact sheet; the academic reviews (Rehman 2016, Leitão 2021) consistently grade it “promising, needs bigger independent trials.” Regulatory bodies in Malaysia and abroad have issued contamination warnings. The institutional position is “real potential, watch the supply chain.”
What to know about tongkat ali
Trials report modest hormone and cortisol changes with specified extracts at 200–400 mg daily. Compare the concentration and amount with the research. A plant name or extract ratio alone does not guarantee the studied effect.
Frequently asked questions about Tongkat Ali
Does tongkat ali really increase testosterone?
Modestly, in real trials. Henkel et al. (2014) gave 76 men with low testosterone 200–400 mg/day and saw significant T increases (the share of men with normal T rose from ~36% to ~91% in one month); Talbott (2013) saw cortisol drop and testosterone rise in stressed adults. Best-evidenced testosterone botanical, with the caveat that effects concentrate in men who start low or stressed.
What does 100:1 or 200:1 tongkat extract mean?
The concentration ratio: 100 kg of root condensed to 1 kg of extract. A stated ratio is a quality signal (real extraction happened), though ratios alone aren't standardization. The gold standard is a stated eurycomanone percentage or a named extract like LJ100.
How long does tongkat ali take to work?
Trials run 4–12 weeks. Talbott's cortisol/testosterone changes appeared at 4 weeks; testosterone trials typically report effects at 6–12 weeks. Anything promising results in days is selling placebo.
Is tongkat ali safe?
At studied doses (≤400 mg/day) trials report good tolerance; insomnia and irritability at high doses are the noted complaints. The bigger safety issue is supply chain: regulators have flagged adulterated tongkat products (heavy metals, undeclared drug analogs), so buy standardized, tested brands.
Does tongkat ali help with ED or libido?
Small trials suggest modest benefits; Ismail et al. (2012) found improved erectile-function scores at 300 mg/day over 12 weeks in 109 men. Early-stage evidence; the testosterone/cortisol findings are stronger.
References
- [1]Henkel RR et al. — Tongkat ali for late-onset hypogonadism, RCT (Andrologia, 2014)
- [2]Talbott SM et al. — Eurycoma longifolia on stress hormones and mood, RCT (JISSN, 2013)
- [3]Ismail SB et al. — PHYSTA freeze-dried Eurycoma longifolia for QoL and sexual well-being in men, RCT (Evid Based Complement Alternat Med, 2012)
- [4]Leisegang K, Finelli R et al. — Eurycoma longifolia improves serum total testosterone: systematic review and meta-analysis (Medicina, 2022)
- [5]Rehman SU et al. — Eurycoma longifolia ethnobotany and pharmacology review (Molecules, 2016)
Products we reviewed containing Tongkat Ali
Based on recorded labels or seller-described formulas. Inclusion does not establish a match to the strains, preparations or amounts studied here; check each review's disclosure limits.