Tongkat Ali is the root of Eurycoma longifolia, a traditional Southeast Asian herb also called Longjack. Supplements often use standardized extracts to target compounds such as eurycomanone.

Does Tongkat Ali increase testosterone?

Some studies suggest Tongkat Ali may modestly increase total and free testosterone, especially in men with lower baseline levels. Effects can vary by extract quality, dose, and individual factors.

Can Tongkat Ali help male fertility?

Research in men with fertility concerns suggests it may improve sperm parameters such as count, motility, and morphology. It is not a substitute for medical evaluation of infertility.

Does Tongkat Ali reduce stress or cortisol?

Limited clinical evidence links Tongkat Ali with lower cortisol and improved self-reported mood in stressed individuals. Results are not consistent across all studies.

What is a typical Tongkat Ali dosage?

Common supplemental doses are about 100–400 mg per day of an extract. Follow the product label and consider discussing use with a clinician, especially if you have hormone-related conditions or take medications.

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Vitamin B

Vitamin B1 (Thiamine)

Vitamin B2 (Riboflavin)

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Vitamin B5 (Pantothenic Acid)

Vitamin B6 (Pyridoxine)

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Trimethylglycine (Betaine)

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Coenzym Q10 (Ubiquinone)

Betaine HCL

Nicotinamide Riboside

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Ginsenoside

Lion's Mane (Hericium erinaceus)

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Cat's Claw (Uncaria tomentosa)

Arjuna (Terminalia arjuna)

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Astragalus Polysaccharides

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Glucosamine Sulfate

Chondroitin Sulfate

Glucosamine Sulphate 2KCL

Tongkat Ali

Moderate study situation·7/10

A higher score indicates better study conditions, but not necessarily effectiveness.

Tongkat Ali is a traditional Southeast Asian herbal supplement studied for supporting testosterone, male fertility, stress reduction, and sexual health.

Testosterone Booster Stress Relief Exercise Performance Male Fertility Depression / Mood Enhancement Hormone Balance

dose range

100–400 mg

once daily or split into two doses

Consumption

Take with or without food, ideally earlier in the day to minimize potential sleep disruption. Use standardized extracts confirmed for eurycomanone content.

Not fat-soluble.

Best time

Taking late in the day may cause insomnia in sensitive individuals. Pre-workout timing may be preferred for exercise benefits, but main effects are chronic, not acute.

Description

Tongkat Ali (Eurycoma longifolia), known as Longjack, is a medicinal root used in Southeast Asian traditional medicine. Modern supplements aim to standardize its active compounds, especially eurycomanone.

benefits

Main effects with level of evidence

Moderate

Note on evidence

The most robust evidence is for improvements in male fertility and stress. Evidence for testosterone boost and exercise performance is plausible but mixed in quality.

Supports male fertility

Moderate

Supplementation may improve sperm quality—count, motility, and morphology—in men with fertility challenges.

Particularly relevant for: men seeking fertility support

S1 · PubMed - Tongkat Ali and Male Fertility S6 · International Journal of Preventive Medicine - Eurycoma longifolia evidence review

May increase testosterone levels

Moderate

Data suggest moderate increases in total and free testosterone, particularly in aging men or those with low baseline testosterone.

Particularly relevant for: men with low testosterone · older men

S4 · Examine.com - Eurycoma longifolia S6 · International Journal of Preventive Medicine - Eurycoma longifolia evidence review

Reduces cortisol and stress

Moderate

Tongkat Ali supplementation was associated with lower cortisol and improved self-reported mood and tension in stressed subjects.

Particularly relevant for: adults seeking stress support

S2 · PMC - Tongkat Ali Stress and Mood S4 · Examine.com - Eurycoma longifolia

Enhances sexual health and function

Limited

Tongkat Ali is traditionally used to improve libido; clinical studies show possible benefit for erectile function and libido.

Particularly relevant for: men with mild sexual dysfunction

S3 · WebMD - Eurycoma Longifolia S4 · Examine.com - Eurycoma longifolia

May support exercise performance and muscle strength

Limited

Preliminary studies suggest possible benefits for strength and body composition, but evidence remains limited.

Particularly relevant for: athletes · physically active adults

S5 · NIH ODS - Dietary Supplements for Exercise and Athletic Performance S4 · Examine.com - Eurycoma longifolia

Safety & Information

Important safety information & known risks

For educational purposes only • not medical advice

Generally well-tolerated at recommended doses, but safety data on long-term use are limited.

warning notices

Mild insomnia, irritability, or restlessness may occur with high doses or late-day intake.
Rare reports of liver enzyme elevation, mainly linked to adulterated or contaminated products.
Safety during pregnancy, breastfeeding, and for those with hormonal cancers is not established.
Avoid use during pregnancy or breastfeeding due to insufficient safety data.
Avoid if you have hormone-sensitive conditions or are taking hormonal medications without medical supervision.
Monitor for restlessness or insomnia, especially if taken late in the day.
Use only reputable sources to reduce the risk of contamination with heavy metals or adulterants.

Known interactions with medications

Hormonal medications
Antidiabetic medications
Hepatotoxic drugs

Contraindications / special precautions

pregnancy
breastfeeding
hormone-sensitive cancers

interactions

Important interactions between active ingredient ↔ supplement / medication / food

Tongkat Ali may interact with medications affecting hormones, blood sugar, or the liver.

May affect action of hormonal drugs or impact hormone-sensitive conditions.

drug · Hormonal medications

CautionLimited

Why

Tongkat Ali appears to influence testosterone and possibly estrogen pathways, posing a theoretical risk for those on testosterone or anti-androgen therapy or with hormone-driven cancers.

recommendation

Consult a healthcare provider if taking hormone modulators or diagnosed with hormone-sensitive cancers.

S3 · WebMD - Eurycoma Longifolia S6 · International Journal of Preventive Medicine - Eurycoma longifolia evidence review

May theoretically lower blood glucose levels alongside antidiabetic drugs.

drug · Antidiabetic medications

CautionTheoretical

Why

Some animal data suggest blood sugar–lowering effects.

recommendation

Monitor blood glucose more closely; consult a healthcare provider before use if on diabetes medication.

S4 · Examine.com - Eurycoma longifolia

Potential for liver strain if combined with other hepatotoxic drugs.

drug · Hepatotoxic drugs

CautionLimited

Why

Rare reports of liver enzyme elevation, especially with low-quality or adulterated supplements.

recommendation

Avoid or monitor liver function if also using other liver-stressing medications.

S7 · European Food Safety Authority (EFSA) - Eurycoma longifolia Safety Assessment S3 · WebMD - Eurycoma Longifolia

mechanisms of action

Brief explanations of how it works

Promotes androgenic activity

Contains quassinoids (notably eurycomanone) that may stimulate release of androgens and reduce sex hormone-binding globulin, increasing free testosterone.

S4 · Examine.com - Eurycoma longifolia S6 · International Journal of Preventive Medicine - Eurycoma longifolia evidence review

Reduces cortisol production

Oral supplementation may lower stress-related cortisol, possibly by acting on the hypothalamic-pituitary-adrenal (HPA) axis.

S2 · PMC - Tongkat Ali Stress and Mood

Potential antioxidant and anti-inflammatory effects

Some phytochemicals in Tongkat Ali display antioxidant and anti-inflammatory effects in laboratory models, but human clinical relevance is not fully established.

S6 · International Journal of Preventive Medicine - Eurycoma longifolia evidence review

Sources & References

Primary literature and reviews on which these statements are based

7 sources

PubMed - Tongkat Ali and Male Fertility

PMC - Tongkat Ali Stress and Mood

WebMD - Eurycoma Longifolia

Examine.com - Eurycoma longifolia

NIH ODS - Dietary Supplements for Exercise and Athletic Performance

International Journal of Preventive Medicine - Eurycoma longifolia evidence review

European Food Safety Authority (EFSA) - Eurycoma longifolia Safety Assessment

Last updated: February 1, 2026

This information is for educational purposes only and does not replace medical advice.