Most human trials of tongkat ali (Eurycoma longifolia, also sold as long jack) used 200 to 400 mg a day of a standardized hot-water root extract, with the full range across controlled studies running from 100 to 600 mg a day. Most trials lasted 4 to 12 weeks, and the milligram figure only means something when you know which extract it refers to.
This guide covers the doses used in published studies, why one tongkat ali extract cannot simply be swapped for another, what is known about side effects and interactions, and who should skip it.
Key takeaways
- Common trial doses were 200 to 400 mg a day of a standardized water extract. A few studies used 600 mg a day, and one tested 100 mg a day.
- Most trials lasted 4 to 12 weeks, and the longest ran 6 months. There is very little data on longer use.
- Most of the research used one commercial extract. Products standardized to different markers, or plain root powder, are not interchangeable with it.
- Results are mixed. Several small trials reported hormone or well-being changes, while a 2024 trial at 400 mg a day found no differences from placebo.
- In 2021, EFSA concluded that the safety of a tongkat ali water extract had not been established. Contamination and interactions with medicines are also documented concerns.
What tongkat ali and long jack are
Tongkat ali is a shrub native to Southeast Asia, and its root has a long history of traditional use in Malaysia and neighboring countries. "Long jack" and "Malaysian ginseng" are common names for the same plant, Eurycoma longifolia. Supplements almost always use the root, usually as a concentrated extract rather than ground root.
For how tongkat ali compares with ashwagandha in what each is studied for, see Ashwagandha vs. Tongkat Ali. This article sticks to one question: how much was used, and how to read the number on a label.
Tongkat ali dosage in human studies
The research below concerns tongkat ali as an ingredient, not any finished MAXIS product.
| Study | Daily dose | Duration | Population | What was reported |
|---|---|---|---|---|
| Tambi et al., 2012 | 200 mg standardized water extract | 1 month | 76 men with late-onset hypogonadism; no placebo group | Symptom scores and serum testosterone improved from baseline |
| Talbott et al., 2013 | 200 mg standardized hot-water extract | 4 weeks | 63 moderately stressed adults (32 men, 31 women) | Versus placebo: salivary cortisol 16% lower, salivary testosterone 37% higher, lower tension, anger and confusion scores |
| Ismail et al., 2012 | 300 mg water extract | 12 weeks | 109 men aged 30 to 55 | Physical-functioning scores improved more than with placebo; erectile function and libido scores also rose; safety measures similar to placebo |
| Henkel et al., 2014 | 400 mg extract | 5 weeks | 25 physically active adults aged 57 to 72 (13 men, 12 women); no placebo group | Total and free testosterone and handgrip strength rose from baseline |
| Chinnappan et al., 2021 | 100 or 200 mg water extract | 12 weeks | 105 men aged 50 to 70 with testosterone below 300 ng/dL | Total testosterone higher than placebo in both groups; fatigue and aging-symptom scores lower |
| Chan et al., 2021 | 600 mg extract | 2 weeks | 32 healthy young men | Total testosterone, free testosterone and estradiol changed in favor of the extract group |
| Leitão et al., 2021 | 200 mg extract | 6 months | 45 men with symptoms of age-related androgen deficiency, with or without exercise training | Largest improvement in erectile function scores in the group combining the extract with training |
| Antonio et al., 2024 | 400 mg (extract type not stated) | 4 weeks | 33 exercise-trained men and women | No differences from placebo in body composition, strength, mood, sleep, or salivary free testosterone and cortisol |
A few patterns stand out. Two of these studies had no placebo group, so their before-and-after changes are hard to interpret. Several were funded or co-authored by the company that makes the extract they tested. And the populations differ widely, from stressed office workers to older men with low testosterone to trained athletes, so a result in one group does not predict a result in another.
What the reviews say about dose and duration
A 2022 systematic review and meta-analysis by Leisegang and colleagues included nine studies, five of which were pooled. It reported a statistically significant increase in total testosterone with tongkat ali, but the authors described the pooled studies as highly inconsistent with one another (I² of about 87%) and noted that they differed in design, population, dose and length, with small samples. Most of the studies used the same commercial extract. In the studies it summarized, daily doses mostly ranged from 100 to 600 mg, and durations from 2 weeks to 6 months.
A broader 2024 systematic review of products sold as testosterone boosters by Morgado and colleagues found that most ingredients failed to raise total testosterone. It rated tongkat ali as possibly effective, a cautious grade that reflects how few trials exist.
The honest reading is that 200 to 400 mg a day of a standardized water extract is the most studied range, that trials rarely ran longer than three months, and that the evidence is promising in some groups but small and not consistent.
Why standardization matters more than the milligram number
Tongkat ali root contains several groups of compounds, and extract makers standardize to different ones. The main markers you will see are:
- Glycosaponins: a broad fraction of plant compounds. The extract EFSA reviewed in 2021 was described as 40 to 65% glycosaponins.
- Eurycomanone: a quassinoid often used as a quality marker. The same EFSA extract contained 0.8 to 1.5% eurycomanone, while an extract used in a 2010 interaction study contained about 0.027%, roughly 30 to 55 times less.
- Eurypeptides: a peptide fraction named in some branded extract specifications. Few published human studies report doses in terms of this marker.
Because of this, 400 mg of one extract and 400 mg of another may deliver very different amounts of each compound. When you compare a product with a study, check three things: the plant part (root), the extraction (most trials used hot-water extracts), and the stated standardization. If a label lists none of these, there is no way to tell how it relates to the research.
Extract vs. raw root powder
The human trials above used concentrated water extracts, not ground root. Plain root powder is a different material, and there is no clinical research establishing an equivalent dose for it. A capsule of powder at the same milligram count as a trial extract should not be assumed to match what was studied.
Tongkat ali side effects and safety concerns
Side effects in trials. In the short trials reviewed by Leisegang and colleagues, adverse events were uncommon. One trial reported digestive symptoms and itching, and another found adverse events at similar rates in the extract and placebo groups. Trials were small and short, so rare effects would not show up.
The EFSA opinion. In 2021, the European Food Safety Authority assessed a standardized tongkat ali water extract proposed as a food supplement at up to 200 mg a day for adults. It noted positive results in genotoxicity tests, including DNA damage in the stomach and duodenum of animals at a high dose, and concluded that safety had not been established under any condition of use. This was a regulatory assessment of one extract, not evidence of harm at trial doses in people, but it is the most formal safety review available.
Contamination and adulteration. Two Malaysian surveys of 100 tongkat ali products each found mercury above the national limit in 36% (2004) and 26% (2006) of the samples tested. Separately, products marketed for male sexual enhancement, a category where tongkat ali is a common ingredient, have been recalled after FDA testing found undeclared prescription drugs. In 2019, for example, a lot of one such product, Green Lumber, was found to contain tadalafil. Buying from brands that test each batch for identity and contaminants matters with this herb.
Interactions. In a small crossover study of 14 healthy men, taking 200 mg of a water extract with a single dose of the blood pressure drug propranolol reduced the drug's overall bioavailability by 29% and its peak blood level by 42%, because less of it was absorbed. Similar studies have not been done for most other medicines.
Case reports. A 2024 case report described liver injury in a man after starting tongkat ali, which improved after he stopped. A single case cannot prove cause, but it is a reason to stop and see a doctor if you notice yellowing of the skin or eyes, dark urine or unusual fatigue.
Who should avoid tongkat ali
- Anyone pregnant or breastfeeding, and anyone under 18.
- People with hormone-sensitive conditions, unless a doctor approves it.
- Anyone taking prescription medication, especially heart or blood pressure drugs, without first checking with a doctor or pharmacist.
- People with a history of liver problems.
Where MAXIS fits
MAXIS Ashwagandha+ provides 400 mg of Eurycoma longifolia root extract (Eury Gold 28®, standardized to 28% glycosaponins and 10% eurypeptides) per two-capsule serving, alongside 600 mg KSM-66® ashwagandha, 200 mg velvet bean (15% L-Dopa), 50 mg tribulus, 50 mg muira puama and 50 mg maca. It helps the body adapt to stress and supports energy, stamina and healthy hormone balance.† It is not for anyone under 18, pregnant or breastfeeding. Consult your healthcare provider if you have a thyroid, autoimmune or hormone-sensitive condition or take medication, and stop two weeks before surgery. For more on its ashwagandha, see What Is KSM-66 Ashwagandha?
MAXIS Men's Vitality provides 200 mg of LongJax® long jack root extract per two-capsule serving, with 500 mg Testosurge® fenugreek, 120 mg Shoden® ashwagandha, 100 mg Liboost® damiana, 15 mg zinc and 3 mg boron. It supports healthy testosterone levels already within the normal range.† For the fenugreek research, see Fenugreek and Testosterone.
Both amounts fall within the 200 to 400 mg range most often used in trials. These are branded extracts with their own specifications, so the trials are a guide to the range studied rather than a direct match for either product. Do not take Ashwagandha+ and Men's Vitality together: both contain ashwagandha and tongkat ali. Eury Gold 28® is a registered trademark of HP Ingredients, and LongJax® is a registered trademark of AIDP Inc.
FAQ
How much tongkat ali per day was used in studies?
Most trials used 200 to 400 mg a day of a standardized water extract. The full range in controlled studies was 100 to 600 mg a day. These figures refer to concentrated extracts, not raw root powder.
How long does tongkat ali take to work?
Trials measured outcomes after 2 weeks to 6 months, most often 4 to 12 weeks. Some reported changes within a few weeks, while a 4-week trial at 400 mg a day found no difference from placebo.
What are the side effects of tongkat ali?
Short trials reported few side effects, mainly digestive upset and itching. Bigger concerns are product contamination, interactions with medicines such as propranolol, rare case reports of liver injury, and EFSA's 2021 conclusion that safety had not been established.
Is long jack the same as tongkat ali?
Yes. Long jack, tongkat ali and Malaysian ginseng are all names for Eurycoma longifolia. Products can still differ a great deal in extraction and standardization.
References
- Tambi MI, Imran MK, Henkel RR (2012). Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia. PubMed
- Talbott SM, Talbott JA, George A, Pugh M (2013). Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. Journal of the International Society of Sports Nutrition. PubMed
- Ismail SB, Wan Mohammad WM, George A, Nik Hussain NH, Musthapa Kamal ZM, Liske E (2012). 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. Evidence-Based Complementary and Alternative Medicine. PubMed
- Henkel RR, Wang R, Bassett SH, Chen T, Liu N, Zhu Y, Tambi MI (2014). Tongkat Ali as a potential herbal supplement for physically active male and female seniors: a pilot study. Phytotherapy Research. PubMed
- Chinnappan SM, George A, Pandey P, Narke G, Choudhary YK (2021). 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. Food & Nutrition Research. PubMed
- Chan KQ, Stewart C, Chester N, Hamzah SH, Yusof A (2021). The effect of Eurycoma longifolia on the regulation of reproductive hormones in young males. Andrologia. PubMed
- Leitão AE, Vieira MCS, Pelegrini A, da Silva EL, Guimarães ACA (2021). A 6-month, double-blind, placebo-controlled, randomized trial to evaluate the effect of Eurycoma longifolia (Tongkat Ali) and concurrent training on erectile function and testosterone levels in androgen deficiency of aging males (ADAM). Maturitas. PubMed
- Antonio J, Evans C, Pereira F, et al. (2024). The effect of Tongkat Ali supplementation on body composition in exercise-trained males and females. Applied Sciences. DOI
- Leisegang K, Finelli R, Sikka SC, Panner Selvam MK (2022). Eurycoma longifolia (Jack) improves serum total testosterone in men: a systematic review and meta-analysis of clinical trials. Medicina (Kaunas). PubMed
- Morgado A, Tsampoukas G, Sokolakis I, Schoentgen N, Urkmez A, Sarikaya S (2024). Do "testosterone boosters" really increase serum total testosterone? A systematic review. International Journal of Impotence Research. PubMed
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Bohn T, et al. (2021). Safety of Eurycoma longifolia (Tongkat Ali) root extract as a novel food pursuant to Regulation (EU) 2015/2283. EFSA Journal. DOI
- Salman SA, Amrah S, Wahab MS, Ismail Z, Ismail R, Yuen KH, Gan SH (2010). Modification of propranolol's bioavailability by Eurycoma longifolia water-based extract. Journal of Clinical Pharmacy and Therapeutics. PubMed
- Ang HH, Lee EL, Cheang HS (2004). Determination of mercury by cold vapor atomic absorption spectrophotometer in Tongkat Ali preparations obtained in Malaysia. International Journal of Toxicology. PubMed
- Ang HH, Lee KL (2006). Contamination of mercury in tongkat Ali hitam herbal preparations. Food and Chemical Toxicology. PubMed
- Kaliounji A, Shadid G, Saba H, Ahlawat S (2024). A rare case of Tongkat Ali-induced liver injury: a case report. Cureus. PubMed
- U.S. Food and Drug Administration (2019). GL Holdings issues voluntary worldwide recall of Green Lumber products due to presence of undeclared tadalafil. FDA Recalls, Market Withdrawals and Safety Alerts. FDA
†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
