Benefits
Supports healthy testosterone levels in aging men
In a 12-week placebo-controlled trial in 105 men aged 50 to 70 with low testosterone, 200 mg a day raised total testosterone from week 4, and 100 mg raised it by week 12. Free testosterone did not differ from placebo. The trial was funded by the extract's maker. In a 6-month trial in men with signs of low testosterone, the extract combined with exercise training raised total testosterone.
Erectile function and sexual well-being scores
In a 12-week placebo-controlled trial in 109 men aged 30 to 55, 300 mg a day improved erectile function scores, libido and physical functioning. A small 12-week trial of the extract combined with Polygonum minus also improved sexual performance scores. Both trials had maker employees as authors, and the combination result cannot be credited to tongkat ali alone.
Lower salivary cortisol and tension in stressed adults
In a 4-week placebo-controlled trial in 63 moderately stressed men and women, 200 mg a day lowered salivary cortisol by 16 percent and raised salivary testosterone by 37 percent compared with placebo. Tension, anger and confusion scores also fell. The trial was funded by the extract's maker.
Standardized eurypeptide and glycosaponin content
LJ100 is sold with a set content of eurypeptides, glycosaponins and eurycomanone, so each batch should be similar. Standardization is about product consistency; the evidence for effects comes from the trials described above, which name the extract Physta.
Mechanism of action
Eurycomanone and testosterone production (proposed)
In laboratory studies, eurycomanone, a compound in tongkat ali root, increased testosterone production by testicular cells and blocked aromatase, the enzyme that converts testosterone to estrogen. Researchers propose this as one explanation for the rise in testosterone seen in trials; it has not been confirmed in people.
Eurypeptides and DHEA (proposed)
Tongkat ali root contains bioactive peptides called eurypeptides, which researchers propose act through DHEA, a hormone the body can convert to testosterone. In the 12-week trial in aging men, DHEA rose within the extract groups, but this was not compared with placebo.
Clinical trials
Randomized, double-blind, placebo-controlled multicentre trial of 100 mg or 200 mg a day of Physta for 12 weeks (Chinnappan et al. 2021, Food Nutr Res)
105 men aged 50 to 70 with total testosterone below 300 ng/dL.
Total testosterone rose compared with placebo at week 12 on 100 mg and from week 4 on 200 mg. Free testosterone did not differ from placebo. Aging Male Symptoms and fatigue scores fell compared with placebo. Cortisol fell and strength rose within the groups, but these were not compared with placebo. Mild stomach complaints occurred in six people. Funded by Biotropics Malaysia, the maker.
Randomized, double-blind, placebo-controlled four-arm trial of 200 mg a day of Eurycoma longifolia, with or without supervised training three times a week (Leitao et al. 2021, Maturitas)
45 men averaging 47 years old with androgen deficiency of aging males.
Erectile function improved with both the extract and training, with the largest improvement in men who trained and took the extract; the authors report that this combination also raised total testosterone. The paper does not name the extract brand; HP Ingredients describes this study as LJ100 research.
Randomized, placebo-controlled trial of 200 mg a day of Physta for 4 weeks (Talbott et al. 2013, J Int Soc Sports Nutr)
63 adults (32 men, 31 women) screened for moderate stress.
Compared with placebo, salivary cortisol was 16 percent lower and salivary testosterone 37 percent higher, and tension, anger and confusion scores fell. The study was funded by Biotropics Malaysia, and one author worked for the company.
Randomized, double-blind, placebo-controlled trial of 300 mg a day of Physta for 12 weeks (Ismail et al. 2012, Evid Based Complement Alternat Med)
109 men aged 30 to 55.
Erectile function scores, libido and the physical functioning score of a quality of life survey improved compared with placebo, and sperm motility and semen volume rose. Safety measures were similar to placebo. The trial was funded by Biotropics Malaysia, and two authors worked for it.
Randomized, double-blind, placebo-controlled trial of a 300 mg combination of Physta and Polygonum minus for 12 weeks (Udani et al. 2014, Evid Based Complement Alternat Med)
Men aged 40 to 65; 12 in the active group and 14 in the placebo group completed the study.
Erection hardness, sexual health and aging symptom scores improved more than with placebo, and the product was well tolerated. The study was small, several authors were from the maker, and the result cannot be credited to tongkat ali alone.
Uncontrolled study of 200 mg a day of a standardized water-soluble tongkat ali extract for 1 month (Tambi et al. 2012, Andrologia)
76 men with late-onset hypogonadism.
Aging Male Symptoms scores improved and the share of men with normal testosterone rose from 35.5 to 90.8 percent. There was no placebo group, so the change cannot be separated from time or expectation. A later paper by the maker identifies the extract as Physta.