Who this is for: Men thinking about tongkat ali who want the honest safety picture before they start.
What you'll get: What the trials checked, the rare problems that have been reported, what's known about the liver, kidneys, heart and hair, and when to talk to your doctor.
Reading time: 6 minutes. Every source is linked, so you can read them yourself.
In small, short human trials of up to 12 weeks, tongkat ali showed no safety problems that mattered at the doses studied. But it's not risk-free. There are rare reported cases of liver injury and one of a heart rhythm problem, it can interact with at least one blood pressure drug, and some products have tested high for mercury.
If you searched "tongkat ali side effects" or "is tongkat ali safe", that's the honest answer. Honesty is the product. If we can't prove it, we don't say it. So below is what's known, what isn't, and when you should talk to your doctor first.
Is tongkat ali safe? What the human studies checked
Only a few human trials have looked at safety directly, by running blood tests before and after. Here's what they checked.
| Study | Who was in it | Daily dose | How long | What they checked | What they found |
|---|---|---|---|---|---|
| Chinnappan et al., 2021 (placebo-controlled) | 105 men aged 50 to 70 | 100 or 200 mg | 12 weeks | Blood count, cholesterol, liver and kidney function | No safety-related changes that mattered clinically |
| Chen et al., 2014 (placebo-controlled crossover) | 13 healthy male recreational athletes | 400 mg | 6 weeks | Liver and kidney function | No significant changes |
| George et al., 2018 (placebo-controlled, tongkat ali plus multivitamins) | 93 adults aged 25 to 65 | Combined product | 24 weeks | Vital signs, metabolic panel, kidney tests | No significant changes in vital signs or the metabolic panel |
On top of that, a 2022 review of the clinical trials said tongkat ali may be "a safe and promising" option, while saying more research is needed (Leisegang et al., 2022).
Two things to keep in mind. These trials are small and short. And all three had an author who works for the company that makes the extract they tested. That's common in supplement research, and it's worth knowing.
Tongkat ali side effects: liver, kidneys, heart and hair
Liver
In the trials above, liver tests didn't change in a way that mattered. But outside the trials, there's a real signal you should know about.
In 2024, doctors in New York reported a 47-year-old man who developed acute liver injury, with jaundice and raised liver enzymes, shortly after starting tongkat ali. He got better after he stopped taking it. The authors called it the first reported case of its kind (Kaliounji et al., 2024). LiverTox, the US government's database on drug and supplement liver injury, also notes reports of liver injury linked to tongkat ali in bodybuilders (LiverTox).
Case reports are rare and can't prove cause on their own. But we'd rather you hear it from us. If you notice yellow skin or eyes while taking any supplement, stop and see a doctor.
Kidneys
Two placebo-controlled trials of tongkat ali on its own ran kidney function tests: one for 12 weeks at 100 or 200 mg, one for 6 weeks at 400 mg. Neither found a change that mattered (Chinnappan, 2021; Chen, 2014). We didn't find any human case reports of kidney problems on PubMed.
What we don't know: none of these trials included men with existing kidney disease. If you have a kidney condition, talk to your doctor before you take any supplement.
Heart and blood pressure
There's very little human data here. One 24-week trial of tongkat ali plus multivitamins found no significant changes in vital signs (George, 2018). That's a combined product, so it doesn't tell us about tongkat ali alone.
In 2025, a cardiologist in the UK reported a 71-year-old man who developed atrial flutter, a fast heart rhythm, after starting tongkat ali. The author called it a "probable" case and the first one documented (Ali, 2025). One case is one case. But if you get palpitations or dizziness after starting it, stop and get checked.
Hair loss
This is one of the most searched worries, and the honest answer is short. We searched PubMed and found no human study on tongkat ali and hair loss. Not one showing it causes hair loss, and not one showing it doesn't.
The worry comes from the idea that anything touching testosterone might speed up hair thinning. That's a theory, not something anyone has tested with tongkat ali. If you're already losing hair and it bothers you, ask a dermatologist before you start.
Medication interactions
This one is real and tested. In a small trial of 14 healthy young men, taking 200 mg of tongkat ali extract with the blood pressure drug propranolol lowered how much of the drug got into the blood. The authors advised caution when taking the two together (Salman et al., 2010).
Nobody has tested tongkat ali with most other medications. So if you take any prescription drug, talk to your doctor or pharmacist first.
Heavy metals: check the bottle
Two studies from Malaysia tested 100 products containing tongkat ali each for mercury. In the first, 36 of the 100 products were over the Malaysian limit. In the second, 26 of 100 were (Ang et al., 2004; Ang and Lee, 2006). The 2004 study also warned that one clean batch doesn't mean the next one is clean.
Those studies are old and from one market. But the lesson holds: buy from a brand that tests for heavy metals and will tell you so.
Who should talk to a doctor before taking tongkat ali
- Anyone on prescription medication, especially blood pressure or heart drugs
- Anyone with a liver, kidney or heart condition
- Anyone with a hormone-related condition, or who is already on testosterone therapy
- Anyone under 18
- Women who are pregnant or breastfeeding
That's not us covering ourselves. Most of these groups weren't in the trials above, so there's little or no data on how it goes for them.
How to take it sensibly
- Stay in the studied range: the human trials above used 100 to 400 mg a day of a root extract. More is not better when nobody has tested it.
- Start alone: one new supplement at a time, so you know what's doing what.
- Know the stop signs: yellow skin or eyes, a racing or uneven heartbeat, or anything that feels off. Stop and see a doctor.
- Get blood work if you can: a routine check with your doctor before and after a few months gives you real numbers instead of guesses.
Tongkat ali is one tool, not the answer
Anyone who tells you a supplement has zero side effects either hasn't read the research or hopes you won't. Your energy and drive start with the basics: sleep, lifting heavy things, morning sunlight and doing something hard on purpose. Tongkat ali can sit next to those. It can't replace them.
For the full picture on benefits, doses and studies, read our tongkat ali guide.
That's how we built All Day Fire Tongkat Ali. It's version one: 400 mg of a 100:1 hot-water root extract per serving, one ingredient, made in small batches by a US manufacturer and tested for heavy metals. The studies above are about tongkat ali, not about our bottle.
FAQ
What are the side effects of tongkat ali?
In short human trials of up to 12 weeks, tongkat ali didn't cause changes that mattered in liver or kidney tests. Outside trials, there are rare case reports of liver injury and one of a heart rhythm problem. Talk to your doctor before starting if you take medication or have a health condition.
Is tongkat ali bad for your kidneys?
Two placebo-controlled trials of tongkat ali on its own, one of 12 weeks and one of 6 weeks at 400 mg a day, found no meaningful change in kidney function tests. Nobody has studied men with existing kidney disease, so if that's you, ask your doctor first.
Is tongkat ali bad for your liver?
Liver tests didn't change in a way that mattered in the trials. But a 2024 case report described a man who developed liver injury after starting tongkat ali and recovered after stopping. If you notice yellow skin or eyes, stop and see a doctor.
Does tongkat ali cause hair loss?
Nobody knows. There's no human study on tongkat ali and hair loss on PubMed, either way. If you're worried about hair thinning, talk to a dermatologist before you start.
Can tongkat ali interact with medication?
Yes, at least one. A small 2010 trial found tongkat ali lowered how much of the blood pressure drug propranolol got into the blood. Most other drugs haven't been tested, so check with your doctor or pharmacist first.
Sources
- Chinnappan SM, et al. 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 Nutr Res, 2021. PMID 34262417
- Chen CK, et al. Supplementation of Eurycoma longifolia Jack Extract for 6 Weeks Does Not Affect Urinary Testosterone: Epitestosterone Ratio, Liver and Renal Functions in Male Recreational Athletes. Int J Prev Med, 2014. PMID 25013692
- George A, et al. Efficacy and safety of Eurycoma longifolia (Physta) water extract plus multivitamins on quality of life, mood and stress: a randomized placebo-controlled and parallel study. Food Nutr Res, 2018. PMID 30574050
- Leisegang K, et al. Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials. Medicina, 2022. PMID 36013514
- Kaliounji A, et al. A Rare Case of Tongkat Ali-Induced Liver Injury: A Case Report. Cureus, 2024. PMID 38646387
- Tongkat Ali. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. National Institute of Diabetes and Digestive and Kidney Diseases, updated 2024. PMID 39527684
- Ali M. Tongkat Ali-Induced Atrial Flutter: A Probable Case. Cureus, 2025. PMID 41080360
- Salman SA, et al. Modification of propranolol's bioavailability by Eurycoma longifolia water-based extract. J Clin Pharm Ther, 2010. PMID 21054461
- Ang HH, et al. Determination of mercury by cold vapor atomic absorption spectrophotometer in Tongkat Ali preparations obtained in Malaysia. Int J Toxicol, 2004. PMID 15162849
- Ang HH, Lee KL. Contamination of mercury in tongkat Ali hitam herbal preparations. Food Chem Toxicol, 2006. PMID 16567029
Written and reviewed by Nick Lange, All Day Fire. Last reviewed 5 Oct 2026.
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. This article is for information only and is not medical advice. Talk to your doctor before starting any supplement.