Tongkat Ali Side Effects (2026): What the Evidence Shows

Last updated: November 6, 2026 · Published by Eternal Elixir

Tongkat ali side effects look uncommon in the controlled trials. In the largest safety-focused trial, men who took 100 or 200 mg a day of a standardized water extract for 12 weeks showed no clinically relevant changes in blood, liver or kidney tests. The risks that do show up sit elsewhere: two published case reports (one liver, one heart rhythm), a measured drug interaction, and product quality, since surveys have found mercury and fake ingredients in some tongkat products. This guide sorts that evidence by type so you can see which risks apply to you.

Disclosure: Eternal Elixir makes and sells supplements. When our own products appear in a comparison, they are named as Eternal Elixir products. No brand pays to be included. Our editorial standards

Tongkat ali side effects in placebo-controlled trials

The best evidence on safety comes from trials that compared tongkat ali with a dummy pill and ran routine blood tests along the way. The largest of these was published in 2021 in Food & Nutrition Research. It enrolled 105 men aged 50 to 70 with low testosterone and gave them 100 mg or 200 mg of a standardized water extract, or placebo, every day for 12 weeks.

The researchers checked complete blood counts, cholesterol, and liver and kidney function, and reported no clinically relevant safety changes. Total testosterone rose more than placebo in both extract groups. The extract maker funded the study, which is worth knowing when you weigh it.

Other trials point the same way, but most were small and short. They tested specific extracts at 100 to 600 mg a day, so their results describe those products at those doses. None was designed to test people with liver disease or a heart rhythm problem, so they say little about those groups. For the full list of trial doses by goal, see our tongkat ali dosage guide.

Online forums add another layer. People there describe irritability, restlessness or poor sleep, often after taking it many days in a row. Those accounts are anecdotes without a placebo group, but they are a reasonable thing to watch for in the first few weeks.

Tongkat ali side effects sorted by type of evidence

Most lists of tongkat ali side effects mix trial results, single case reports and rat studies as if they carried the same weight. They don’t. This table sorts the published evidence by what kind of study produced it, which changes how much each finding should worry you.

Read down the right-hand column and a pattern appears. The herb itself looks well tolerated in short trials. Most of the avoidable risk comes from who takes it, what they take it with, and whose capsule it is.

Rare but serious reports: liver and heart

Liver injury

In 2024, doctors in New York described the first published case of liver injury linked to tongkat ali in Cureus. A 47-year-old man developed yellowing of the eyes, raised liver enzymes and jaundice shortly after he began taking it, and he needed a hospital stay. He improved once he stopped. The team ruled out other causes and urged extra care in people who take several supplements at once, where the culprit is harder to pin down.

Heart rhythm

A 2025 report in Cureus describes a 71-year-old man who came to hospital after four days of palpitations and dizziness. Tests showed atrial flutter, a fast and regular rhythm problem in the upper chambers of the heart. His thyroid and blood salts were normal, and doctors found no other trigger. Because the problem started soon after he began tongkat ali, they judged it the probable cause.

Two cases among the many people who take tongkat ali do not make these common side effects. They do show what to watch for. Yellow skin or eyes, dark urine, a racing or irregular heartbeat and dizziness are all reasons to stop and call a doctor the same day.

What not to mix with tongkat ali

The clearest interaction on record comes from a randomized crossover trial in the Journal of Clinical Pharmacy and Therapeutics. Fourteen healthy young men took 80 mg of propranolol, a beta blocker used for blood pressure and heart conditions, with either placebo or 200 mg of tongkat ali water extract. With the herb, the total amount of propranolol absorbed fell by 29% and the peak level fell by 42%, while the time to reach that peak stretched by about 86%. The researchers traced it to slower absorption in the gut and advised caution with the combination.

No other drug has been tested this way, so the safe assumption is that any medicine you rely on could be affected. Talk to your doctor or pharmacist before you start if you take:

• heart or blood pressure medicine, including beta blockers;
• diabetes medicine;
• testosterone or other hormone treatment;
• any medicine where a small drop in absorption would matter.

Stacking adds its own risk. Two tongkat products taken together double the dose without any trial behind the total. Blends deserve a closer read too.

Eternal Elixir’s Tongkat Ali + Fadogia 2010mg pairs 500 mg of tongkat ali with 1,500 mg of fadogia agrestis, an herb with no reliable human trials and a rat study that raised testicular safety concerns. Our comparison of tongkat ali vs fadogia agrestis explains the difference before you choose a blend.

The bottle matters: contamination and fake tongkat ali

Some tongkat ali side effects have nothing to do with the plant. A survey published in Food and Chemical Toxicology tested 100 tongkat products bought in Malaysia and found that 26 of them held 0.53 to 2.35 ppm of mercury, above the 0.5 ppm limit set there. A later study in Pharmaceutical Biology used DNA barcoding on tongkat products and found that only 37% were authentic while 27% were adulterated. In at least one case, a product that passed the DNA check lacked the expected marker compound when chemists analyzed it.

Both surveys came from Malaysian research teams, but the lesson travels. Choose a brand that names the species and extract ratio on the label and tests each batch. Eternal Elixir’s Tongkat Ali 200:1 Extract 2000mg lists Eurycoma longifolia root extract at a declared 200:1 ratio, with 2,000 mg in each 3-capsule serving.

Every Eternal Elixir batch is third-party lab tested, and a certificate of analysis is available on request. A bottle holds 90 capsules, or 30 servings, for $29.99 at the current sale price, which works out to $1.00 per serving.

The Eternal Elixir product page is also clear that a 200:1 ratio describes concentration and does not make the capsule equivalent to the standardized extracts used in trials. This finished product has not been clinically tested. That is one more reason to start low and watch how you respond. If you are comparing labels across brands, our tongkat ali supplement comparison sets them side by side.

How to lower your risk of tongkat ali side effects

You can’t control every risk, but most of the avoidable ones come down to a few habits.

• Check your medicines first. Bring the bottle to your doctor or pharmacist if you take anything on prescription.
• Start low. If you try tongkat ali, consider 1 capsule a day for the first week before moving to the full 3-capsule serving on the Eternal Elixir label. No trial has tested this, so treat it as a tolerance check.
• Keep to one product. Use the label serving as your ceiling and don’t stack tongkat products.
• Take it in the morning. If restlessness or poor sleep is going to show up, an earlier dose keeps it away from bedtime.
• Know the stop signs. Yellow skin or eyes, dark urine, palpitations or dizziness mean stop and get checked.

Some people should skip tongkat ali or only use it with medical advice. That includes anyone who:

• is pregnant, breastfeeding or trying to conceive;
• is under 18;
• has a liver condition, a heart rhythm problem or kidney disease;
• has a hormone-sensitive condition, such as prostate problems;
• takes prescription medicine, especially for the heart or blood pressure.

If your main goal is supporting healthy testosterone, our evidence guide to raising testosterone naturally covers sleep, training and diet steps that carry no interaction risk at all. And if you decide tongkat ali suits you, our guide to what tongkat ali does for men shows which outcomes the trials actually measured.

Tongkat ali side effects: frequently asked questions

What happens if I take tongkat ali every day?

In the controlled trials, people took tongkat ali every day, mostly for 4 to 12 weeks. In the largest safety-focused trial, men aged 50 to 70 took 100 or 200 mg daily for 12 weeks and showed no clinically relevant changes in blood counts, cholesterol, or liver and kidney tests. Nobody has studied daily use for years. If you take it daily, use the label serving as your limit and stop if you notice restlessness, poor sleep or a racing heart.

What not to mix with tongkat ali?

The one measured interaction is with propranolol, a beta blocker: tongkat ali cut the amount of the drug absorbed by 29% in a small trial. Ask your doctor before combining it with any prescription medicine, especially heart, blood pressure, diabetes or hormone treatments. Avoid stacking two tongkat products, and check blends for other herbs such as fadogia.

Does tongkat ali affect the heart?

One case report describes a 71-year-old man who developed atrial flutter, a fast heart rhythm, after starting tongkat ali. His doctors judged the herb the probable cause after ruling out other triggers. It is the only published case, and the trials did not report heart problems. If you have a heart rhythm condition, speak to your cardiologist first, and stop and get checked if you feel palpitations or dizziness.

What does tongkat ali do for a man?

Trials in men have looked at testosterone, stress, sexual well-being and strength. In men aged 50 to 70 with low testosterone, 200 mg a day raised total testosterone compared with placebo from week 4. Our guide to tongkat ali benefits for men covers each outcome and the doses behind it.

Is tongkat ali bad for your liver?

Liver and kidney tests stayed normal in a 12-week placebo-controlled trial, and rats given high doses of the powdered root for 13 weeks showed no organ damage. One published case describes a 47-year-old man who developed jaundice after starting tongkat ali and recovered after stopping it. If you have a liver condition or drink heavily, ask your doctor first.

Can tongkat ali cause irritability or trouble sleeping?

Some people in online forums describe irritability or restless sleep when they take it many days in a row. Those are personal reports, not trial findings. Taking it in the morning and keeping to the label serving are simple ways to see whether it affects you.