Tongkat Ali: The Evidence-Backed Testosterone Booster From Southeast Asia
Tongkat Ali has centuries of traditional use and a growing body of clinical evidence. Here's what it can and can't do for testosterone, stress, and performance.
The Basics
| What it is | A Southeast Asian medicinal plant (Eurycoma longifolia) with clinical evidence for increasing free testosterone and reducing cortisol in stressed or aging individuals |
| Primary use | Supporting testosterone levels, reducing cortisol, improving libido and male fertility |
| Evidence level | Moderate — multiple human RCTs with positive results; mechanisms increasingly understood |
| Safety profile | Generally Safe — extensive traditional use; studies show good tolerability up to 300-400 mg/day of standardized extract |
| Best for | Men over 35 with low testosterone, high stress (elevated cortisol), reduced libido, or athletes seeking natural testosterone support |
⚡ Key Facts at a Glance
- Works by increasing the free-to-bound ratio of testosterone — reduces SHBG, freeing up bound testosterone for bioavailability
- Also reduces cortisol by ~16% in clinical stress exposure studies — making it unique as a testosterone-support + adaptogen combo
- Look for products standardized to eurycomanone content (1-2%) from the root extract — most "tongkat ali" products are underdosed
- LJ100® is a patented, clinically-researched extract used in most positive studies — the benchmark for quality
- Multiple human RCTs show improvements in testosterone, sperm quality, and sexual function — particularly in stressed populations
Walk into any supplement store and the testosterone support section is packed with overblown promises attached to underresearched ingredients. Tongkat Ali — also known as Eurycoma longifolia or Malaysian ginseng — is a notable exception. With decades of traditional use in Southeast Asia and a steadily growing body of peer-reviewed clinical research, it stands apart from most in its category.
What Is Tongkat Ali?
Tongkat Ali is a flowering plant native to Malaysia, Indonesia, Thailand, and surrounding regions. Its root has been used in traditional medicine for centuries, primarily as an adaptogen and aphrodisiac. Modern research has begun to substantiate many of these traditional uses, particularly around hormonal support and stress resilience.
The primary bioactive compounds are quassinoids — specifically eurycomanone — along with peptides and polysaccharides that appear to influence the hypothalamic-pituitary-gonadal (HPG) axis.
How It Works on Testosterone
The proposed mechanisms center on two pathways. First, Tongkat Ali appears to stimulate the release of luteinizing hormone (LH) from the pituitary gland, which signals the testes to produce more testosterone. Second, it contains compounds that may inhibit sex hormone-binding globulin (SHBG), the protein that binds testosterone in the bloodstream and renders it inactive. By reducing SHBG binding, more free testosterone becomes biologically available.
This is an important distinction. Tongkat Ali isn't a direct testosterone precursor — it works upstream, nudging the body's own hormonal regulation system rather than bypassing it.
What the Clinical Evidence Shows
A 2012 study published in the Journal of the International Society of Sports Nutrition found that men with late-onset hypogonadism who took 200 mg/day of a standardized Tongkat Ali extract (Physta®) for one month saw testosterone levels normalize in 90% of subjects, compared to 35% in the placebo group. Testosterone levels increased by an average of 46%.
A separate randomized controlled trial involving stressed adults — both male and female — found that 200 mg/day of the same extract significantly reduced cortisol levels, improved testosterone:cortisol ratio, and reduced self-reported tension and anger. This study highlights its adaptogenic dimension: Tongkat Ali may work partly by lowering the chronic cortisol that suppresses testosterone production.
Research in recreational athletes has also shown modest improvements in muscle strength and body composition over 5–8 week periods, though effect sizes vary.
Who Benefits Most
The clearest benefit is seen in men with suboptimal testosterone — those experiencing symptoms of low-T (fatigue, reduced libido, difficulty building muscle, poor mood) without clinical hypogonadism requiring medical treatment. This "gray zone" is where Tongkat Ali shines.
It also appears useful for chronically stressed individuals. Since cortisol and testosterone exist in a roughly inverse relationship — sustained high cortisol suppresses testosterone production — an adaptogen that lowers the cortisol burden can shift this balance meaningfully.
Men in their 30s, 40s, and beyond who want to support natural testosterone production without pharmaceutical intervention are the core audience.
Dosage and What to Look For
The most studied dose is 200–400 mg/day of a standardized water-soluble extract. Look for products standardized to at least 40:1 concentration or specifically using the Physta® or LJ100® branded extracts, which are the ones with the strongest clinical backing.
Quality matters significantly. Root extract from the right part of the plant, at the right concentration, is very different from low-grade root powder. Don't buy cheap bulk powder and expect the same results as the studied extracts.
Expectations and Realistic Outcomes
Tongkat Ali is not a replacement for testosterone replacement therapy (TRT). If levels are severely suppressed, it won't close that gap. But for men in the functional low-normal range looking to optimize naturally, it can be a meaningful tool.
Most users report improvements in energy, libido, and mood within 4–6 weeks of consistent use. Strength and body composition changes take longer — typically 8–12 weeks of consistent training and supplementation.
Safety Profile
Tongkat Ali has a strong safety record at standard doses. No significant adverse effects have been observed in clinical trials at doses up to 400 mg/day. Some users report increased energy that can disrupt sleep if taken late in the day — morning dosing is generally recommended.
It's not recommended during pregnancy. Those with hormone-sensitive conditions should consult a physician before use.
Bottom Line
In a category full of noise, Tongkat Ali has earned its reputation. It's not a miracle — but for men looking to support hormonal health through natural means, the evidence is solid enough to take seriously.
What the Experts Say
Opinions below are paraphrased from each expert's public work, interviews, and podcasts — not direct quotes.
🧠 Andrew Huberman
Andrew Huberman has discussed tongkat ali (Eurycoma longifolia) in the context of testosterone optimization on his podcast, citing some of the clinical research on its effects on free testosterone, SHBG reduction, and cortisol. He considers LJ100 the evidence-backed standardized extract and has mentioned considering its use, though he emphasizes bloodwork-guided supplementation rather than supplementing blindly.
🥩 Paul Saladino
Paul Saladino has discussed adaptogens and hormone-supporting plants with characteristic nuance — acknowledging that some plant compounds like tongkat ali have meaningful clinical data while maintaining that the foundational approach to testosterone is diet (animal foods, cholesterol), training, sleep, and stress management rather than supplementation.
🎙️ Joe Rogan
Joe Rogan has discussed testosterone optimization approaches on the JRE and has mentioned tongkat ali as one of the natural approaches that fighters and athletes explore before considering pharmaceutical options. He's expressed interest in compounds with actual clinical evidence for testosterone support.
Sources & Further Reading
- Talbott SM, et al. "Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects." Journal of the International Society of Sports Nutrition. 2013. https://jissn.biomedcentral.com/articles/10.1186/1550-2783-10-28
- Tambi MI, et al. "Standardised water-soluble extract of Eurycoma longifolia raises testosterone levels in infertile men." Asian Journal of Andrology. 2012. https://pubmed.ncbi.nlm.nih.gov/21671978/
- Leisegang K, et al. "Eurycoma longifolia Reduces Fatigue and Improves Physical Performance." Phytomedicine. 2022. https://pubmed.ncbi.nlm.nih.gov/35868253/
Where to Buy / Find This
- Thorne Phytisone — Ashwagandha and adaptogen blend — for standalone tongkat ali, see UMZU below — https://www.thorne.com/products/dp/phytisone
- Pure Encapsulations Tongkat Ali — Standardized Tongkat Ali (Longjack) extract for testosterone and vitality support — https://www.pureencapsulations.com/tongkat-ali.html
- UMZU Tongkat Ali — 100:1 extract standardized for eurycomanone content — testosterone and vitality support — https://umzu.com/products/tongkat-ali