Tongkat Ali: Complete Guide to Benefits, Dosage & Research

Mike HartnettEvidence-Based

7+ years researching longevity protocols. Runs a 20+ supplement daily stack. Built CoreStacks after losing his father to heart disease.

Affiliate disclosure: CoreStacks may earn a commission on purchases made through links on this page, at no extra cost to you. We only recommend products we trust.

Tongkat ali is the one testosterone-support supplement that actually has decent human data behind it — and I say that as someone who’s skeptical of 90% of the “test boosters” on the market. I added it to my stack 18 months ago after Huberman discussed the research on his podcast, and my free testosterone went from 12.1 to 16.8 ng/dL over 3 months. That’s one data point, not a clinical trial. But the published studies mostly point the same direction. The catch? Dosing, sourcing, and extract standardization matter enormously. Most tongkat ali products are underdosed junk. This guide covers what the research actually shows, what dose works, and which products are worth buying.

What Is Tongkat Ali?

Tongkat ali (also known as longjack or Eurycoma longifolia) is a flowering plant native to Southeast Asia, particularly Malaysia and Indonesia, where it’s been used for centuries as a traditional remedy for energy, libido, and male vitality. The root is the part used medicinally.

Modern research has validated many traditional claims, with clinical trials showing meaningful effects on testosterone levels, cortisol, body composition, and exercise performance. Unlike many “testosterone boosters” in the supplement market, tongkat ali actually has a respectable evidence base.

The active compounds include quassinoids (particularly eurycomanone), alkaloids, and various flavonoids. Standardized extracts typically specify eurycomanone content, with well-researched brands using a 100:1 or 200:1 root extract standardized to 2–3% eurycomanone.

How Does Tongkat Ali Work?

Tongkat ali appears to work through several complementary mechanisms for testosterone optimization. It reduces the binding of testosterone to sex hormone-binding globulin (SHBG), which increases the amount of free (bioavailable) testosterone in circulation. It may also stimulate Leydig cell function in the testes, supporting testosterone production directly.

Additionally, tongkat ali has cortisol-lowering (adaptogenic) properties. Since cortisol and testosterone have an inverse relationship — chronic high cortisol suppresses testosterone — reducing cortisol indirectly supports testosterone levels. A study found cortisol reductions of about 16% with tongkat ali supplementation.

Dr. Andrew Huberman has discussed tongkat ali’s mechanisms on his podcast, noting that its multi-pronged approach (SHBG reduction + cortisol lowering + potential direct stimulation) makes it more plausible than many testosterone-boosting supplements.

Key Benefits

Testosterone Optimization

A 2022 meta-analysis of randomized controlled trials found that tongkat ali supplementation significantly increased total testosterone levels compared to placebo. A notable 2012 study in stressed adults found tongkat ali increased testosterone by 37% while reducing cortisol by 16%. The effects appear most pronounced in men with suboptimal (not clinically low) testosterone levels.

Body Composition and Exercise Performance

A 2014 study found that 400 mg of tongkat ali daily for 5 weeks significantly improved muscular strength and arm circumference in recreationally active men. Another study showed improvements in body composition, with reductions in body fat percentage. These effects are likely downstream of improved testosterone-to-cortisol ratio.

Stress and Cortisol Reduction

The adaptogenic properties of tongkat ali are well-documented. A 4-week study in moderately stressed subjects found significant reductions in tension, anger, and confusion, alongside measurable cortisol reductions and testosterone increases. This stress-hormone balancing effect is relevant for longevity, as chronic cortisol elevation accelerates aging.

Fertility and Reproductive Health

Multiple studies show tongkat ali improves semen quality, including sperm concentration, motility, and morphology. A study of idiopathic male infertility found that 200 mg daily for 9 months resulted in pregnancies for 14.7% of the couples enrolled — a meaningful outcome for a supplement intervention.

Optimal Dosage and Timing

Clinical trials have used 200–400 mg per day of standardized tongkat ali extract. The most studied dose is 200 mg of a 100:1 water extract (Physta or equivalent). Dr. Huberman has mentioned 400 mg as a common dose.

Timing: Morning, with food. Some people cycle it (5 days on, 2 off), though this isn’t strictly necessary based on current evidence.

Extract quality: This is critical. Look for water-extracted root standardized to eurycomanone content. The Malaysian-sourced Physta/LJ100 extracts have the most clinical data. Avoid products that don’t specify extract ratio or standardization.

Cycling: While not strictly required by evidence, many experts (including Huberman) suggest cycling — either 5 on/2 off weekly, or 4–6 weeks on, 1–2 weeks off.

Potential Side Effects

Tongkat ali is generally well-tolerated. Possible side effects include:

• Restlessness or insomnia (if taken late in the day)
• Increased body temperature (uncommon)
• Irritability at higher doses
• GI discomfort (rare)

Who should be cautious: People with hormone-sensitive cancers (prostate, breast) should consult their oncologist. Those with heart conditions should be aware of potential heart rate increases. Women who are pregnant or breastfeeding should avoid it.

Drug interactions: May interact with blood pressure medications and blood thinners. Check the CoreStacks Interaction Checker.

Which Expert Protocols Include Tongkat Ali?

Dr. Andrew Huberman has discussed tongkat ali favorably on the Huberman Lab podcast and has reportedly used it himself. He emphasizes the importance of sourcing quality extracts and cycling the supplement.

Dr. Brad Stanfield has reviewed tongkat ali in his evidence-based series, noting the clinical evidence is more strong than most testosterone-boosting supplements, though he emphasizes managing expectations.

See how tongkat ali compares across expert approaches: Longevity Expert Stacks Compared.

Best Tongkat Ali Products

Quality and sourcing are important for tongkat ali. Look for standardized Malaysian root extracts:

See our recommended longevity stacks for 2026

Frequently Asked Questions

Does tongkat ali actually increase testosterone?

Yes, multiple RCTs and a meta-analysis confirm modest but significant testosterone increases, particularly in men with suboptimal levels or high stress. The effect is not as dramatic as testosterone replacement therapy, but it’s meaningful — typically 10–37% increases in total testosterone depending on the study population.

Can women take tongkat ali?

Yes, though it’s less studied in women. Some women use it for energy, libido, and cortisol management. The testosterone-boosting effects in women appear to be modest and unlikely to cause virilization at standard doses, but research is limited.

How long does tongkat ali take to work?

Most studies measure outcomes at 4–12 weeks. Some users report improved energy within 1–2 weeks, but the hormonal and body composition effects typically take 4–8 weeks to become apparent. Consider getting baseline testosterone levels checked before starting and retesting at 8–12 weeks. See our blood tests guide.

Related Articles

• Andrew Huberman’s Complete Supplement Stack 2026
• Longevity Blood Tests Guide 2026
• Longevity Expert Stacks Compared
• Best Longevity Stack Under $200

This article is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement regimen.