Tongkat Ali

Tongkat ali refers to Eurycoma longifolia, a slender, medium-sized tree or shrub in the family Simaroubaceae that grows across Indochina and the Malay Archipelago, including Malaysia, Indonesia, Thailand, and Vietnam ^[1]. Its long taproot has a bitter taste and has been used for centuries in Southeast Asian folk medicine, where preparations of the root, bark, flowers, and fruit were employed for fevers and malaria, dysentery, aches, and as a general tonic and aphrodisiac ^[1][2]. In modern usage it is best known as a herbal supplement taken by athletes and by older men.

The root contains dozens of phytochemicals, among them quassinoids such as eurycomanone, eurycomalactone, and eurycomanol, along with alkaloids, coumarins, and other constituents, several of which show biological activity in the laboratory ^[2]. Research interest has centered on the plant's reputed effects on male hormones and vitality. Some small randomized and animal studies report improvements in testosterone levels, sperm quality, erectile function, or markers of stress, particularly in men with low baseline testosterone or under physical strain ^[3][4], while an evidence-based systematic review concluded that the overall quality of the human data is limited and that many claims remain insufficiently proven ^[1]. Laboratory work has also identified anti-inflammatory constituents that inhibit the NF-κB signaling pathway ^[2].

Eurycoma longifolia is sold internationally as a dietary supplement rather than an approved medicine, and certain standardized extracts have obtained generally recognized as safe status in the United States ^[1]. Reported side effects are usually mild and may include nausea, digestive upset, and headache, though rare cases of liver injury have been described, mostly among bodybuilders using multi-ingredient products. Quality and adulteration have been recurring concerns; surveys have found some commercial products contaminated with heavy metals such as mercury, and regulators have acted against supplements spiked with undeclared prescription erectile dysfunction drugs. Because harvesting typically requires uprooting the whole plant, sustainability has become an issue, prompting cultivation programs in producing countries.

Generally well tolerated in studies at standardized doses, with occasional reports of insomnia, restlessness, or irritability, likely tied to its activating and hormonal effects. Because it can shift hormones, people with hormone-sensitive conditions or those on hormonal therapy should be cautious. Quality and heavy-metal contamination have been concerns with some cheap sources, so third-party tested extracts matter. Long-term human safety data are still limited.