Supplement
Tongkat ali is a Southeast Asian shrub whose root extract has long been used in traditional medicine and is thought to influence male hormones, including testosterone. People mostly look at it for sexual health and vitality, and the evidence is moderate: a meta-analysis of randomized trials found erections went up. That finding came from a single small group of 128 people, so it is too early to say how well it holds up in larger or longer studies.
Sources: PMID 26365449
- Updated
- How we grade
- 10 studies cited
- Best evidence
- Grade B
- Conditions studied
- 13
- Outcomes
- 112
- Graded outcomes
- 0154
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Erections Small Increase | Improves (the measure goes up) | Small effect | 1 study | 128 people | ||
| Testosterone | Improves (the measure goes up) | 4 studies | 109 people | |||
Studies that measured testosterone
| ||||||
| Sperm Quality | Improves (the measure goes up) | 1 study | 109 people | |||
| IGF-1 | Improves (the measure goes up) | 109 people | ||||
| Libido | Improves (the measure goes up) | 109 people | ||||
| Seminal Motility | Improves (the measure goes up) | 109 people | ||||
| Serum DHEA | Improves (the measure goes up) | 109 people | ||||
| Sex Hormone Binding Globulin | Improves (the measure goes up) | 109 people | ||||
| Subjective Well-Being | Improves (the measure goes up) | 109 people | ||||
| Weight | Changes; see studies | 109 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Body Fat Small Increase | Improves (the measure goes down) | Small effect | 45 people | |||
| Testosterone | Improves (the measure goes up) | 4 studies | 457 people | |||
Studies that measured testosterone
| ||||||
| Strength | Improves (the measure goes up) | 2 studies | 150 people | |||
Studies that measured strength
| ||||||
| Aerobic Exercise Metrics Small Detriment | Worsens (the measure goes down) | Small effect | 45 people | |||
| Cortisol | Improves (the measure goes down) | 105 people | ||||
| DHEAS | Improves (the measure goes up) | 105 people | ||||
| Estrogen | Changes; see studies | 32 people | ||||
| Fatigue Symptoms | Improves (the measure goes down) | 105 people | ||||
| Follicle-Stimulating Hormone | Improves (the measure goes up) | 32 people | ||||
| Free Testosterone | Improves (the measure goes up) | 137 people | ||||
| HbA1c | Improves (the measure goes down) | 105 people | ||||
| High-density lipoprotein (HDL) | Improves (the measure goes up) | 45 people | ||||
| IGF-1 | Improves (the measure goes up) | 105 people | ||||
| Low-density lipoprotein (LDL) | Improves (the measure goes down) | 45 people | ||||
| Luteinizing Hormone | Improves (the measure goes up) | 32 people | ||||
| Sex Hormone Binding Globulin | Improves (the measure goes up) | 137 people | ||||
| Thyroid-Stimulating Hormone | Improves (the measure goes up) | 105 people | ||||
| Triglycerides | Improves (the measure goes down) | 45 people | ||||
| Waist circumference | Improves (the measure goes down) | 45 people | ||||
Mood Improvement
- Cortisol: improves
- Testosterone: improves
- Stress Signs and Symptoms: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Cortisol Small Decrease | Improves (the measure goes down) | Small effect | 63 people | |||
| Testosterone | Improves (the measure goes up) | 4 studies | 63 people | |||
Studies that measured testosterone
| ||||||
| Stress Signs and Symptoms | Changes; see studies | 63 people | ||||
Stress
- Cortisol: improves
- Testosterone: improves
- Stress Signs and Symptoms: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Cortisol Small Decrease | Improves (the measure goes down) | Small effect | 63 people | |||
| Testosterone | Improves (the measure goes up) | 4 studies | 63 people | |||
Studies that measured testosterone
| ||||||
| Stress Signs and Symptoms | Changes; see studies | 63 people | ||||
Healthy Muscle Aging
- Cortisol: improves
- Testosterone: improves
- Strength: improves
Anaerobic Exercise Performance
- Power Output: improves
- Strength: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Power Output Small Improvement | Improves (the measure goes up) | Small effect | 40 people | |||
| Strength | Improves (the measure goes up) | 2 studies | 40 people | |||
Studies that measured strength
| ||||||
Hormone Health
- Blood Urea Nitrogen
- Testosterone: improves
- Strength: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood Urea Nitrogen No effect | NoneNo effect | 25 people | ||||
| Testosterone | Improves (the measure goes up) | 4 studies | 57 people | |||
Studies that measured testosterone
| ||||||
| Strength | Improves (the measure goes up) | 2 studies | 25 people | |||
Studies that measured strength
| ||||||
| Blood Urea Nitrogen (BUN) | Improves (the measure goes up) | 25 people | ||||
| Cortisol | Changes; see studies | 25 people | ||||
| Creatine Kinase | Changes; see studies | 25 people | ||||
| DHEAS | Improves (the measure goes up) | 25 people | ||||
| Estrogen | Changes; see studies | 32 people | ||||
| Follicle-Stimulating Hormone | Improves (the measure goes up) | 32 people | ||||
| Free Testosterone | Improves (the measure goes up) | 57 people | ||||
| Hematocrit | Improves (the measure goes up) | 25 people | ||||
| Hemoglobin | Improves (the measure goes up) | 25 people | ||||
| Luteinizing Hormone | Improves (the measure goes up) | 32 people | ||||
| Sex Hormone Binding Globulin | Improves (the measure goes up) | 57 people | ||||
Muscle Size Strength
- Bilirubin
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bilirubin No effect | NoneNo effect | 13 people |
Immune Health
- B Cell Count
- Neutrophil Count: improves
- CD4 Lymphocytes: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| B Cell Count No effect | NoneNo effect | 84 people | ||||
| Neutrophil Count | Improves (the measure goes up) | 1 study | 84 people | |||
| CD4 Lymphocytes | Improves (the measure goes up) | 84 people | ||||
| CD8 Lymphocytes | Improves (the measure goes up) | 84 people | ||||
| Lymphocyte Count | Improves (the measure goes up) | 84 people | ||||
| Mood | Improves (the measure goes up) | 84 people | ||||
| Natural Killer Cell Content | Improves (the measure goes up) | 84 people | ||||
| T Cell Count | Improves (the measure goes up) | 84 people | ||||
Muscle Size & Strength
- Bilirubin
- Strength: improves
- Uric Acid: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bilirubin No effect | NoneNo effect | 13 people | ||||
| Strength | Improves (the measure goes up) | 2 studies | 40 people | |||
Studies that measured strength
| ||||||
| Uric Acid | Changes; see studies | 1 study | 13 people | |||
| Blood Urea Nitrogen | Improves (the measure goes up) | 13 people | ||||
| Creatinine | Improves (the measure goes up) | 13 people | ||||
| Gamma-Glutamyltransferase | Improves (the measure goes up) | 13 people | ||||
| Kidney Function | Improves (the measure goes up) | 13 people | ||||
| Liver Enzymes | Changes; see studies | 13 people | ||||
| Power Output | Improves (the measure goes up) | 40 people | ||||
| Urea | Improves (the measure goes up) | 13 people | ||||
| Urinary Albumin | Improves (the measure goes up) | 13 people | ||||
General Athletic Performance
- Testosterone: improves
- Strength: improves
- Uric Acid: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Testosterone | Improves (the measure goes up) | 4 studies | 105 people | |||
Studies that measured testosterone
| ||||||
| Strength | Improves (the measure goes up) | 2 studies | 190 people | |||
Studies that measured strength
| ||||||
| Uric Acid | Changes; see studies | 1 study | 13 people | |||
| Aerobic Exercise Metrics Small Detriment | Worsens (the measure goes down) | Small effect | 45 people | |||
| Bilirubin | Changes; see studies | 13 people | ||||
| Blood Urea Nitrogen | Improves (the measure goes up) | 13 people | ||||
| Body Fat | Changes; see studies | 45 people | ||||
| Cortisol | Changes; see studies | 105 people | ||||
| Creatinine | Improves (the measure goes up) | 13 people | ||||
| DHEAS | Improves (the measure goes up) | 105 people | ||||
| Fatigue Symptoms | Changes; see studies | 105 people | ||||
| Free Testosterone | Improves (the measure goes up) | 105 people | ||||
| Gamma-Glutamyltransferase | Improves (the measure goes up) | 13 people | ||||
| HbA1c | Changes; see studies | 105 people | ||||
| High-density lipoprotein (HDL) | Improves (the measure goes up) | 45 people | ||||
| IGF-1 | Improves (the measure goes up) | 105 people | ||||
| Kidney Function | Improves (the measure goes up) | 13 people | ||||
| Liver Enzymes | Changes; see studies | 13 people | ||||
| Low-density lipoprotein (LDL) | Changes; see studies | 45 people | ||||
| Power Output | Improves (the measure goes up) | 40 people | ||||
| Sex Hormone Binding Globulin | Improves (the measure goes up) | 105 people | ||||
| Thyroid-Stimulating Hormone | Improves (the measure goes up) | 105 people | ||||
| Triglycerides | Changes; see studies | 45 people | ||||
| Urea | Improves (the measure goes up) | 13 people | ||||
| Urinary Albumin | Improves (the measure goes up) | 13 people | ||||
| Waist circumference | Changes; see studies | 45 people | ||||
Aerobic Exercise Performance
- Strength: improves
- Aerobic Exercise Metrics: worsens
- Body Fat: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Strength | Improves (the measure goes up) | 2 studies | 45 people | |||
Studies that measured strength
| ||||||
| Aerobic Exercise Metrics Small Detriment | Worsens (the measure goes down) | Small effect | 45 people | |||
| Body Fat | Changes; see studies | 45 people | ||||
| Waist circumference | Changes; see studies | 45 people | ||||
Erectile Dysfunction
- Erections: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Erections | Improves (the measure goes up) | 1 study | 128 people |
Key findings
- ErectionsImproves (the measure goes up)
- Body FatImproves (the measure goes down)
- CortisolImproves (the measure goes down)
Shop the evidence-backed picks
Tongkat Ali products we can link to, in the forms the graded studies used where we can match them.
- Grade B
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Studies cited
10 studies from PubMed
- Randomized Clinical Trial on the Use of PHYSTA Freeze-Dried Water Extract of Eurycoma longifolia for the Improvement of Quality of Life and Sexual Well-Being in Men
- Efficacy of Tongkat Ali (Eurycoma longifolia) on erectile function improvement: systematic review and meta-analysis of randomized controlled trials.
- Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism?
- The effect of Eurycoma Longifolia on the regulation of reproductive hormones in young males.
- Effect of Eurycoma longifolia standardised aqueous root extract-Physta ® on testosterone levels and quality of life in ageing male subjects: a randomised, double-blind, placebo-controlled multicentre study
- Exercise associated or not to the intake of Eurycoma longifolia improves strength and cardiorespiratory fitness in men with androgen deficiency
- Tongkat Ali as a potential herbal supplement for physically active male and female seniors--a pilot study.
- Effects of Jack Supplementation Combined with Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic Power, and Urinary Testosterone: Epitestosterone Ratio in Young Males.
- Supplementation of Eurycoma longifolia Jack Extract for 6 Weeks Does Not Affect Urinary Testosterone: Epitestosterone Ratio, Liver and Renal Functions in Male Recreational Athletes.
- Immunomodulation in Middle-Aged Humans Via the Ingestion of Physta® Standardized Root Water Extract of Eurycoma longifolia Jack--A Randomized, Double-Blind, Placebo-Controlled, Parallel Study.