from NIH PubMed
Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects.
Eurycoma longifolia is a medicinal plant commonly called tongkat ali (TA) and "Malaysian ginseng." TA roots are a traditional "anti-aging" remedy and modern supplements are intended to improve libido, energy, sports performance and weight loss. Previous studies have shown properly-standardized TA to stimulate release of free testosterone, improve sex drive, reduce fatigue, and improve well-being.
Significant improvements were found in the TA group for Tension (-11%), Anger (-12%), and Confusion (-15%). Stress hormone profile (salivary cortisol and testosterone) was significantly improved by TA supplementation, with reduced cortisol exposure (-16%) and increased testosterone status (+37%).
These results indicate that daily supplementation with tongkat ali root extract improves stress hormone profile and certain mood state parameters, suggesting that this "ancient" remedy may be an effective approach to shielding the body from the detrimental effects of "modern" chronic stress, which may include general day-to-day stress, as well as the stress of dieting, sleep deprivation, and exercise training.
Tongkat Ali as a potential herbal supplement for physically active male and female seniors-a pilot study.
Tongkat Ali (Eurycoma longifolia; TA) is known to increase testosterone levels and alleviate aging males' symptoms. This study aimed at investigating TA as an ergogenic supplement for elderly people. Thirteen physically active male and 12 physically active female seniors (57-72 years) were supplemented with 400-mg TA extract daily for 5 weeks. Standard hematological parameters were taken. In addition, the concentrations of total and free testosterone, dihydroepiandrosterone, cortisol, insulin-like growth factor-1, and sex hormone-binding globulin were analyzed. As additional biochemical parameters, blood urea nitrogen and creatine kinase as parameters of kidney function and muscle damage, respectively, as well as the muscle strength by a simple handgrip test were determined. After treatment, hemoglobin, testosterone, and dihydroepiandrosterone concentrations, and the ratio of total testosterone/cortisol and muscle force remained significantly lower in female seniors than in male seniors. Hematocrit and erythrocyte count in male seniors increased slightly but were significantly higher than in female seniors. Treatment resulted in significant increases in total and free testosterone concentrations and muscular force in men and women. The increase in free testosterone in women is thought to be due to the significant decline in sex hormone-binding globulin concentrations. The study affirms the ergogenic benefit of TA through enhanced muscle strength.
Tongkat Ali extract on reproductive functions
Because previous studies are limited to only few sperm parameters or testosterone concentration, this study investigated the in vivo effects of TA on body and organ weight as well as functional sperm parameters in terms of safety and efficacy in the management of male infertility. Forty-two male rats were divided into a control, low-dose (200 mg kg(-1) BW) and high-dose (800 mg kg(-1) BW) group (n = 14). Rats were force-fed for 14 days and then sacrificed. Total body and organ weights of the prostate, testes, epididymides, gastrocnemius muscle and the omentum were recorded. Moreover, testosterone concentration, sperm concentration, motility, velocity, vitality, acrosome reaction and mitochondrial membrane potential (MMP) were assessed. Whilst TA decreased BW by 5.7% (P = 0.0276) and omentum fat by 31.9% (P = 0.0496), no changes in organ weights were found for the prostate, testes and epididymides. Testosterone concentration increased by 30.2% (P = 0.0544). Muscle weight also increased, yet not significantly. Whilst sperm concentration, total and progressive motility and vitality increased significantly, MMP improved markedly (P = 0.0765) by 25.1%. Because no detrimental effect could be observed, TA appears safe for possible treatment of male infertility and ageing male problems.
Sexual arousal in sexually sluggish old male rats after oral administration of Eurycoma longifolia Jack
Eurycoma longifolia Jack commonly known as Tongkat Ali in Malaysia, has been used in Malaysia to increase male virility and sexual prowess. The objective of this study is to evaluate sexual arousal in sexually sluggish old male rats, 24 months old and retired breeders, receiving 200, 400, or 800 mg/kg of various fractions of E. longifolia Jack, twice daily, for 10 days. Control rats received 3 ml/kg of normal saline. The aphrodisiac effect was monitored by the act of yawning and stretching because yawning, either alone or associated with stretching, is considered an ancestral vestige surviving throughout evolution that promotes sexual arousal. The results showed that 800 mg/kg of E. longifolia Jack increased yawning by 50% and stretching by 16.7% in sexually sluggish old male rats, by 676-719% and 31-336%, respectively, in sexually active male rats, and by 22-44% and 75-100%, respectively, in middle aged, 9 months old and retired breeders. We conclude that the results of this study support the folk use of this plant as an aphrodisiac.