BH
Adaptogen / Hormonal Support

Tongkat Ali (Eurycoma longifolia)

Southeast Asian medicinal root with the strongest human evidence base for testosterone support. Standardised extracts (Physta®, LJ100) show consistent improvements in free testosterone, LH, and stress hormone ratios across multiple RCTs.

hormonal-optimizationenergyperformancestress-resilience
Tier A— Well-tolerated — strong human evidence
Evidence gradeB — Controlled trials / Cohort studies
JS

Reviewed & fact-checked by

Dr. Jane Smith, MD, PhD

Chief Medical Reviewer · Last updated: March 1, 2026

Verified

Mechanism of Action

Tongkat Ali (Eurycoma longifolia) is a tropical tree native to Malaysia, Indonesia, and Thailand. Its bioactive components — eurycomanone (quassinoids), glycopeptides, and beta-carboline alkaloids — work through several complementary pathways.

Key mechanisms:

  • LH-testosterone axis stimulation — eurycomanone stimulates luteinising hormone (LH) release from the pituitary gland, driving increased testosterone synthesis in Leydig cells
  • SHBG reduction — decreases sex hormone-binding globulin concentration, increasing the proportion of free (biologically active) testosterone
  • Adaptogenic action — reduces cortisol and improves the testosterone-to-cortisol ratio, a key marker of anabolic status in athletes []

Key Research

A 2012 RCT in 76 men with late-onset hypogonadism (standardised Physta® extract, 200 mg/day, 1 month): testosterone returned to normal range in 90.8% of participants versus 35.5% in the placebo group. []

Stacking Interactions

How Tongkat Ali (Eurycoma longifolia) interacts with other compounds

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AshwagandhaSynergisticmoderate evidence

Complementary hormonal stack: Tongkat Ali raises LH and supports testosterone production; Ashwagandha lowers cortisol which would otherwise suppress it. Together they target both sides of hormonal balance.

Safety Profile — Tier A

Well-tolerated — strong human evidence

Contraindications

  • ●Hormone-sensitive cancers
  • ●Immunosuppression therapy

Side Effects

  • ●Mild insomnia if taken too late in the day
  • ●Increased body temperature in some users
  • ●Restlessness at high doses

Drug Interactions

Warfarin — may affect coagulationHormone replacement therapy

Research References

  1. [1]PubMed: 22234399
  2. [2]PubMed: 24386995