Tongkat Ali vs Ashwagandha: What the Evidence Shows

Neither tongkat ali nor ashwagandha has been shown to be clearly better for testosterone. Ashwagandha has more randomized trials behind it and is mainly studied for stress and cortisol, with a 2026 meta-analysis reporting higher testosterone in men,^[1] while tongkat ali is studied more directly for testosterone, with a 2022 meta-analysis of five trials reporting higher total testosterone.^[3] Both bodies of research are small and short, so talk to a doctor before using either.

Ashwagandha and tongkat ali are two of the most popular herbal supplements marketed for testosterone, and they are frequently mentioned together. But they are not the same thing, and the research behind each is thinner than the marketing suggests. This article summarizes what published human trials have actually found, where the evidence is weak, and what safety issues to know about.

This article is educational and is not medical advice. Supplements are not intended to diagnose, treat or prevent any condition. Talk to a doctor before starting any supplement, especially if you take medication or have a health condition.

Ashwagandha: The Stress Modulator

Ashwagandha (Withania somnifera) is a root used in Ayurvedic medicine. Its reputation in the testosterone space comes largely from research on stress and cortisol. The idea is that if chronic stress is suppressing the hormonal axis, easing stress may help, though this is a hypothesis rather than an established mechanism.

In a 60-day randomized, placebo-controlled trial of 64 adults with chronic stress, 300 mg of a high-concentration full-spectrum root extract twice daily reduced scores on stress questionnaires and lowered serum cortisol compared with placebo.^[6] A 2026 systematic review and meta-analysis of 23 randomized, placebo-controlled trials (1,706 participants) reported a significant cortisol reduction (SMD about -1.18) and an increase in testosterone in men (mean difference 57.43 ng/dL), though the authors noted heterogeneity and limited data for some outcomes.^[1]

That trial, a 16-week crossover study, used a branded extract (Shoden) delivering 21 mg of withanolide glycosides a day. Ashwagandha was associated with an 18% greater DHEA-S increase and a 14.7% greater testosterone increase than placebo, but the researchers found no significant between-group differences in cortisol, estradiol, fatigue, vigor or sexual well-being, and they called for larger studies.^[2] Testosterone and DHEA-S were measured in saliva.

In an 8-week trial of 57 young men starting resistance training, those taking 300 mg of ashwagandha root extract twice daily had larger increases in serum testosterone, strength and muscle size than the placebo group.^[7] These are short trials of one to a few dozen people each, and effects in other groups (for example, men with normal testosterone who already train) are unknown.

The National Center for Complementary and Integrative Health summarizes the evidence as limited: some data suggest 2 to 4 months of ashwagandha may increase testosterone and sperm quality, and some preparations may help with insomnia and stress, but evidence on anxiety is unclear.^[8]

Tongkat Ali: The Traditional Root Extract

Tongkat ali (Eurycoma longifolia), also called longjack or Malaysian ginseng, is a Southeast Asian root. Proposed mechanisms, such as effects on luteinizing hormone or SHBG, come mainly from animal and laboratory research, and have not been firmly established in men.

In a 4-week randomized, placebo-controlled study of 63 moderately stressed adults (32 men and 31 women), 200 mg a day of a branded hot-water extract of tongkat ali root was associated with a 16% lower salivary cortisol and a 37% higher salivary testosterone than placebo, along with lower tension, anger and confusion scores.^[9]Note that these results are for the combined group of men and women and were measured in saliva, and the study was funded by the extract's manufacturer, so the 37% figure cannot be assumed to apply to men with low testosterone.

A separate uncontrolled study gave 200 mg a day of a water-soluble extract for one month to 76 men with symptoms of late-onset hypogonadism. Serum testosterone and symptom scores improved, and the share of men with testosterone in the normal range rose from 35.5% to 90.8%.^[10]Because there was no placebo group, those results cannot be attributed to the extract alone, and late-onset hypogonadism is a medical condition that needs a doctor's evaluation rather than self-treatment.

A 2022 systematic review and meta-analysis of five randomized trials reported a significant pooled increase in total testosterone with E. longifolia (SMD 1.352, 95% CI 0.565 to 2.138), including in hypogonadal men, while concluding that more research is required before clinical use.^[3] The wide confidence interval and the small number of trials mean the true effect is uncertain. For a broader look, see our guide to testosterone supplements and what the evidence supports.

Tongkat Ali vs Ashwagandha: Head-to-Head Comparison

Do You Need Either?

Most evidence for both comes from small, short trials, and the effects on health outcomes (as opposed to lab values) are unclear. If you feel unusually tired, stressed or have low libido, the most useful next step is to speak with a doctor and consider a morning blood test. Low testosterone has many treatable causes, and supplements can mask them.

Can You Take Both?

We did not find clinical trials of ashwagandha and tongkat ali taken together, so their combined effects and safety are unknown. Combining supplements also makes it harder to know which one is causing any side effect. If you and your doctor decide to try one, introducing a single product at a time is the more cautious approach. Some men also look at shilajit, which has its own limited evidence base.

Safety and Interactions

• Liver injury (ashwagandha): A case series of five patients described liver injury, with jaundice appearing 2 to 12 weeks after starting ashwagandha-containing supplements. It was cholestatic or mixed, and liver tests normalized within 1 to 5 months in four of five patients; one was lost to follow-up.^[4] NCCIH notes that liver injury is rare but has been linked to the supplement.^[8] Stop and seek care if you develop yellow skin or eyes, dark urine or severe itching.
• Thyroid, medications and conditions (ashwagandha): NCCIH says it is not recommended for people with autoimmune or thyroid disorders or before surgery, that it should be avoided in pregnancy and while breastfeeding, and that it might interact with medicines for diabetes and high blood pressure, immunosuppressants, sedatives, anticonvulsants and thyroid medication. People with hormone-sensitive prostate cancer should avoid it because it may raise testosterone.^[8]
• Product quality (tongkat ali): In a survey of 100 tongkat ali hitam products sold in Malaysia, 26% contained 0.53 to 2.35 ppm of mercury, above the 0.5 ppm limit for traditional medicines there.^[5] In the US, supplements are not approved by the FDA for safety and effectiveness before sale, so independent third-party testing is worth looking for.
• Long-term safety: NCCIH states there is not enough information to draw conclusions about the long-term safety of ashwagandha.^[8]

The Bottom Line

Ashwagandha and tongkat ali both have some small randomized trials and meta-analyses showing higher testosterone, but the trials are short and small, and neither supplement is a substitute for the foundational habits or for medical evaluation. If you are curious, the sensible path is to discuss it with your doctor, choose independently tested products, and stop if you notice side effects.

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