Tongkat Ali — Mechanism, Benefits, Dosing

Overview

Root extract of Eurycoma longifolia, traditionally used in SE Asia for vitality. Standardized 'Physta' and 'LJ100' extracts (~2% eurycomanone) are the best-studied.

Natural sources

Root extract

Common forms

Physta (2% eurycomanone)
LJ100
Generic 200:1 extracts (variable quality)

Forms & variants of Tongkat Ali

Different chemical forms of Tongkat Ali behave differently. Browse each form's mechanism, bioavailability, and best-use context.

Physta water extract

Tongkat Ali (Physta)

Water-extracted standardized tongkat ali for testosterone and stress.

Fertility protocol

Tongkat Ali (Fertility)

Standardized eurycomanone extract for sperm quality.

Mechanism of action

Quassinoids (especially eurycomanone) inhibit SHBG and aromatase, increasing free testosterone. Also appears to lower cortisol.

Pathways

· SHBG inhibition
· Aromatase inhibition
· Steroidogenesis support

Hormones

· Free testosterone (↑)
· SHBG (↓)
· Cortisol (↓)
· Estradiol (mildly ↓)

Effects on the body

Increases

Free testosterone

Decreases

SHBG

Decreases

Cortisol

Increases

Libido

Supports

Sperm parameters

Organ system effects

Endocrine

Increases free T, reduces SHBG and cortisol; effects clearest in hypogonadal/stressed men.

Reproductive

Improves sperm motility and morphology in subfertile men.

Evidence-based benefits

Increases free testosterone in men with low T

Moderate evidence

Improves libido and erectile function

Moderate evidence

Reduces cortisol and tension under stress

Moderate evidence

Improves sperm parameters

Moderate evidence

Improves body composition with training

Limited evidence

Potential side effects

Common

· Insomnia if taken too late
· Restlessness

Rare

· Mild GI upset

Serious

· Heavy metals contamination in unstandardized products — choose tested brands

Drug interactions

Anti-hypertensives

May additively lower BP.

minor

Anti-diabetics

May affect glucose.

minor

Immunosuppressants

Mild immunostimulant — theoretical interference.

moderate

Safety & non-supplemental interactions

Educational summary — always confirm with your clinician or pharmacist before starting, stopping, or combining with prescription therapy.

Avoid if you are

·Pregnant or breastfeeding (insufficient safety data)
·Children under 18 (unless directed by a clinician)
·Pregnant or breastfeeding
·Children

Avoid with these conditions

·Hormone-sensitive cancers (breast, prostate, ovarian, uterine)
·Hormone-sensitive cancers
·Hemochromatosis (some products test high for mercury)
·Active immune disease

Avoid / monitor with these medications

·Hormonal contraceptives, HRT, tamoxifen, aromatase inhibitors
·Antidiabetic drugs
·Antihypertensives
·Immunosuppressants

Supplement interactions

Pairs well with

Fadogia Agrestis
Popular 'T-stack' — different mechanism (LH-pathway).
Zinc
Foundational cofactor for testosterone synthesis.
Vitamin D3
Both correlated with serum T.

Avoid combining with

Other strong stimulants late in day
Risk of insomnia.

Dosing & bioavailability

Typical dose

200–400 mg/day standardized extract

Beginner dose

100 mg Physta

Study range

100–600 mg/day

Upper safe limit

1,200 mg/day shown safe in trials up to 12 weeks

Best form

Physta or LJ100 — water-extracted, standardized to eurycomanone

Timing

Morning (can cause insomnia if late)

With food?

With or without

Where to buy

Affiliate-style search links to reputable retailers. We don't endorse specific brands — verify third-party testing (USP, NSF, Informed Sport) before purchase.

Herb

Tongkat Ali

Amazon

Wide selection · fast shipping

Herb

Tongkat Ali

iHerb

Global delivery · curated brands

Herb

Tongkat Ali

Thorne

Practitioner-grade · NSF tested

Scientific evidence (12)

RCTAndrologia · 2012

Effect of Eurycoma longifolia on testosterone and quality of life in aging men

Tambi MI, Imran MK, Henkel RR

Open trial, 76 hypogonadal men, 200 mg/day × 1 month.

Key findings

Free and total testosterone normalized in >90%; AMS quality-of-life scores improved.

Open study

RCTAndrologia · 2012

Standardised water-soluble extract of Eichornia, Tongkat Ali, as testosterone booster

Tambi MI, et al.

1-month open trial of 200 mg/d Tongkat Ali in late-onset hypogonadism.

Key findings

Significant increase in testosterone and improvement in aging male symptoms.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — Increases free testosterone in men with low T

Live PubMed search

Live results for "Tongkat Ali Increases free testosterone in men with low T" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "Increases free testosterone in men with low T". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — Improves libido and erectile function

Live PubMed search

Live results for "Tongkat Ali Improves libido and erectile function" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "Improves libido and erectile function". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — Reduces cortisol and tension under stress

Live PubMed search

Live results for "Tongkat Ali Reduces cortisol and tension under stress" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "Reduces cortisol and tension under stress". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — Improves sperm parameters

Live PubMed search

Live results for "Tongkat Ali Improves sperm parameters" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "Improves sperm parameters". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — randomized controlled trial

Live PubMed search

Live results for "Tongkat Ali randomized controlled trial" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — meta-analysis

Live PubMed search

Live results for "Tongkat Ali meta-analysis" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — pharmacokinetics

Live PubMed search

Live results for "Tongkat Ali pharmacokinetics" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "pharmacokinetics". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — safety adverse events

Live PubMed search

Live results for "Tongkat Ali safety adverse events" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "safety adverse events". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewPubMed (NLM) · 1970

PubMed: Tongkat Ali — dose response

Live PubMed search

Live results for "Tongkat Ali dose response" across the PubMed/MEDLINE peer-reviewed index.

Key findings

Opens current human and preclinical literature matching Tongkat Ali and "dose response". Filter by RCT, meta-analysis, or year on the results page.

Open study

Systematic reviewGoogle Scholar · 1970

Google Scholar: Tongkat Ali — clinical evidence

Live Scholar search

Cross-database citation index for Tongkat Ali as it relates to "clinical evidence".

Key findings

Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.

Open study

Educational use only. This profile is not medical advice. Consult a qualified healthcare professional before starting any supplement, especially if you take prescription medication or have a chronic condition.