Last updated: August 2026. Written by Daniel Lazarevic. Fact-checked by Erik Johansson. This content does not replace medical advice.
Tongkat Ali side effects: what the research says about safety
Tongkat ali is generally well tolerated in studies at normal doses (200–400 mg of standardised extract per day), and reported side effects are usually mild – such as restlessness, sleep difficulties with late doses or mild nausea. Serious side effects are uncommon in the available research, but long-term data is limited and the quality of the product matters a great deal.
Below we go through what has actually been reported, which interactions you should be aware of, and who should be cautious. For dosage, see our dosage guide.
Is tongkat ali safe?
In clinical studies on healthy adults, standardised extracts have been used for up to several months without any serious side effects on the liver, kidneys or blood values being observed at normal doses. At the same time, many studies are small and relatively short, which means that safety over very long-term use is less well investigated. A cautious approach is therefore to stick to the recommended dose.
Known and reported side effects
- Restlessness or feeling "wired", especially at higher doses.
- Sleep difficulties if taken late in the day.
- Mild nausea or stomach discomfort, usually milder when taken with food.
- Headache or irritability in some people.
Interactions and who should avoid it
Talk to a doctor before you start if any of the following applies to you:
- You take medication that affects blood sugar, blood pressure or blood thinning.
- You have a hormone-sensitive condition or a health condition that affects hormones.
- You are pregnant or breastfeeding – tongkat ali is not recommended in that case, as safety data is lacking.
- You are under 18 years of age.
Quality and purity as a safety factor
A large part of safety comes down to the product itself. Tongkat ali root can contain heavy metals, and older investigations of unregulated products have found elevated levels. Therefore choose a lab-tested extract with a certificate of analysis – how to assess this is something we go through in the buying guide. All products in our tongkat ali category are tested for purity.
Safe use in practice
In practice, safe use means starting on a low dose, taking it earlier in the day and staying within the recommended amount. If you get side effects that do not ease off, stop and consult a doctor.
Frequently asked questions (FAQ)
Does tongkat ali have side effects?
Yes, but usually mild ones – such as restlessness, sleep difficulties with late doses or mild nausea. Serious side effects are uncommon at normal doses.
Who should not take tongkat ali?
Pregnant and breastfeeding women, people under 18, and anyone taking medication or with a hormone-sensitive condition should consult a doctor first.
Can tongkat ali affect sleep?
In some people, if taken late in the day. Take it in the morning to reduce the risk.
Does it interact with medication?
It could theoretically affect blood sugar and blood pressure. If you take such medication, check with a doctor.
Is it safe long-term?
Short-term studies look reassuring at normal doses, but long-term data is limited. Stick to the recommended dose and consider taking breaks.
If you have symptoms or an illness – contact a healthcare provider. This text is general information, not individual medical advice.
