Last verified: 17 days ago
Tongkat Ali
Also known as: Eurycoma longifolia, Malaysian Ginseng, Longjack, Physta
Evidence under review. — Not yet rated
Southeast Asian herb shown to support testosterone, erectile function, and immunity in clinical trials.
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What it does
Tongkat Ali is a root extract from a Southeast Asian tree (Eurycoma longifolia) used for centuries as a traditional tonic. Clinical trials show it can improve erectile function and raise...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
200 mg/day (standardized root water extract based on clinical trials)
What the Science Says
Tongkat Ali is a root extract from a Southeast Asian tree (Eurycoma longifolia) used for centuries as a traditional tonic. Clinical trials show it can improve erectile function and raise testosterone levels in aging men with androgen deficiency, especially when combined with exercise. A 4-week trial also found it boosted immune markers in middle-aged adults at 200 mg/day.
What It Doesn't Do
Not a proven standalone testosterone booster for healthy young men — trials focused on men with androgen deficiency. Won't replace exercise; best results came from combining it with training. No solid human evidence it builds muscle directly. Not proven to treat narcolepsy or sleep disorders in humans. Antiparasitic effects are lab-only, not proven in people.
Evidence-Based Benefits
Improves erectile function in aging men with androgen deficiency, especially combined with exercise.
Moderate EvidenceEffective at: 200 mg/day
Supporting studies (click to view on PubMed):
Increases total testosterone levels in men with age-related androgen deficiency.
Moderate EvidenceEffective at: 200 mg/day
Supporting studies (click to view on PubMed):
Boosts immune cell counts and immune scoring in middle-aged adults after 4 weeks.
Moderate EvidenceEffective at: 200 mg/day
Supporting studies (click to view on PubMed):
Root extract reduced chemotherapy-related testicular damage and improved sperm quality in male rats.
Weak EvidenceEffective at: 400–800 mg/kg (animal study only)
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Unknown — no pharmacokinetic studies were provided. Standardized water extracts (e.g., Physta®) were used in clinical trials, suggesting formulation matters.
Red Flags to Watch For
- A case report links Tongkat Ali supplementation to new-onset atrial flutter in a 71-year-old — stop use and consult a doctor if you experience palpitations or dizziness
- A case report documents acute liver injury (jaundice, elevated liver enzymes) in a 47-year-old male after starting Tongkat Ali — monitor for signs of liver problems
- Commercial products vary widely in composition — metabolomics analysis found significant differences between branded products and authenticated root extracts
- Most testosterone and erectile function evidence is in older men with diagnosed androgen deficiency, not healthy adults
- Long-term cardiovascular safety has not been established in clinical trials
Products Containing Tongkat Ali
See how Tongkat Ali is used in these analyzed products:
LJ 100 Tongkat Ali by Double Wood Supplements
Supplement
Nugenix Tongkat Ali, Longjack, 200 mg, Capsules
Supplement
Testo-Booster
Supplement
Innerbody Labs Testosterone Support
Supplement
Focus Formula by Best Earth Naturals
Supplement
Double Wood Supplements Collagen Peptides Powder
Supplement
BPI Sports Best Test 120 Tablets
Supplement
Frequently Asked Questions
What does Tongkat Ali do?
Southeast Asian herb shown to support testosterone, erectile function, and immunity in clinical trials.
What is the effective dose of Tongkat Ali?
200 mg/day (standardized root water extract based on clinical trials)
Is Tongkat Ali safe?
A case report links Tongkat Ali supplementation to new-onset atrial flutter in a 71-year-old — stop use and consult a doctor if you experience palpitations or dizziness
What doesn't Tongkat Ali do?
Not a proven standalone testosterone booster for healthy young men — trials focused on men with androgen deficiency.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25