Tongkat Ali · Eurycoma longifolia

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Testosterone & Aging
Tongkat ali is thought to affect testosterone in two ways: by boosting testosterone production in the testes and inhibiting its conversion to estrogen, and by lowering cortisol a little. These mechanisms come mostly from cell and animal studies. In people, a meta-analysis of 5 randomized trials reported higher total testosterone, most firmly in men whose testosterone was low; the often-quoted Tambi 2012 study had no control group.

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A Southeast Asian tree root

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Tongkat ali is the root of a tree from the Southeast Asian rainforest. It is intensely bitter, and local people have long boiled it into a tea. In recent years fitness circles and podcasts have promoted it as a natural testosterone booster: no injections and no prescription drugs, just a root that is supposed to push up testosterone (the main male sex hormone).

The compounds thought to do the work are a class of bitter substances called quassinoids. The lead one is eurycomanone, the name extract makers print on the label with its content. In cell and animal experiments, it holds back the step that turns testosterone into estrogen while nudging the testosterone-making cells in the testes to work harder. Whether the same happens in people has not been shown directly (the chapter How it affects testosterone goes into detail).

The clearest signals in human studies appear in people whose testosterone was already low or who were under long-term stress, and most of those studies are small. The tree grows slowly, and good roots are scarce and valuable, so when you buy tongkat ali, the bigger worry is often what is actually in the bottle.

Educational content, not medical advice — consult a clinician.

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Tongkat Ali · Eurycoma longifolia

Story

Connected to · 1

regulates · 1

Testosterone & Aging
Tongkat ali is thought to affect testosterone in two ways: by boosting testosterone production in the testes and inhibiting its conversion to estrogen, and by lowering cortisol a little. These mechanisms come mostly from cell and animal studies. In people, a meta-analysis of 5 randomized trials reported higher total testosterone, most firmly in men whose testosterone was low; the often-quoted Tambi 2012 study had no control group.

Read full story

Stop 1/5

A Southeast Asian tree root

EVIDENCEREVIEW 1

READ THE ORIGINAL

Tongkat ali is the root of a tree from the Southeast Asian rainforest. It is intensely bitter, and local people have long boiled it into a tea. In recent years fitness circles and podcasts have promoted it as a natural testosterone booster: no injections and no prescription drugs, just a root that is supposed to push up testosterone (the main male sex hormone).

The compounds thought to do the work are a class of bitter substances called quassinoids. The lead one is eurycomanone, the name extract makers print on the label with its content. In cell and animal experiments, it holds back the step that turns testosterone into estrogen while nudging the testosterone-making cells in the testes to work harder. Whether the same happens in people has not been shown directly (the chapter How it affects testosterone goes into detail).

The clearest signals in human studies appear in people whose testosterone was already low or who were under long-term stress, and most of those studies are small. The tree grows slowly, and good roots are scarce and valuable, so when you buy tongkat ali, the bigger worry is often what is actually in the bottle.

Educational content, not medical advice — consult a clinician.