"Scientific Research,
Clinical Trials &
Reviews On Tongkat Ali"

Numerous research have been done to prove the efficacy of Tongkat Ali and results have point clearly that the herb is highly effective in boosting testosterone level in men.

Scientific Studies & Clinical Trials

Tongkat Ali root extracts highly effective as a muscle growth supplement: By British Journal of Sports Medicine

Source: The abstract number 007 of the clinical trial with healthy men can be read at the website of the British Journal of Sports Medicine : http://bjsm.bmjjournals.com

The British Journal of Sports Medicine reported that in a double-blind placebo controlled scientific trial, the use of Tongkat Ali extract caused a 5 % increase in lean body mass in the treatment group. On the other hand, no significant changes were observed in the placebo group. Among other interesting facts, the journal article states: "The mean arm circumference of the treatment group increased significantly by 1.8 cm after the supplementation, from 30.87 (1.88) to 32.67 (1.96) cm (p = 0.011), but there was no significant increase in the placebo group."

The Ergogenic effects of Tongkat Ali (Eurycoma Longifolia)

The following study was conducted by Prof. S. Hamzah & Dr. A. Yusof in association to the Department of Exercise Physiology, Sports Centre, University of Malaya , 50603 Kuala Lumpur , Malaysia . The conclusion drawn from these results proves that Tongkat Ali root extracts is highly effective in increasing muscle mass and strength.

Source: Abstract is taken from the website of British Journal of Sports Medicine. http://bjsm.bmj.com/cgi/content/full/37/5/464

Eurycoma longifolia, which contains quassinoids such as eurycomalacton, eurycomanon, and eurycomanol, has been reported to have aphrodisiac properties and to increase testosterone levels in men. Previous studies have established that the testosterone supplementation increases fat free mass, muscle strength, and muscle mass, which are important for physical function and athletic performance. Thus, the objective of this study was to investigate the effect of the increase in testosterone levels, obtained by administration of Eurycoma longifolia, on body composition and muscle strength and size in man. Fourteen healthy men performed an intense strength training programme with initial load of 60% RM (2 sets of 10 repetitions with 1 minute rest between, for 10 stations) on alternate days for five weeks. Simultaneously, seven men were randomly selected to consume 100 mg/day Eurycoma longifolia water soluble extract, and seven men received placebo. The intensity of the exercise was increased by 10% RM/week. Body composition, arm circumference, one repetition maximum (1 RM), and surface electromyography (sEMG) activity were measured and recorded one day before and after the five weeks of supplementation and intervention. The lean body mass of the treatment group showed a significant increment, from 52.26 (7.18) kg to 54.39 (7.43) kg (p = 0.012), but no significant changes in fat free mass were observed in the placebo group. Percentage body fat was significantly decreased in the treatment and placebo group, from 31.30 (5.48)% to 28.44 (6.43)% (p = 0.01) and from 22.83 (2.43)% to 21.33 (2.35)% (p = 0.001) respectively. The 1RM test showed a significant increase from 73.71 (16.63) to 78.71 (17.0) kg (p = 0.006) in the treatment group and from 77.29 (8.9) to 79.43 (8.8) kg (p = 0.011) in the placebo group. The increase in strength in the treatment group was larger than in the placebo group (6.78% and 2.77% respectively). The mean frequency of sEMG on the biceps in the treatment and placebo groups decreased significantly, from 121.77 (40.0) to 90.47 (64.6) µV (p = 0.012) and from 127.95 (30.9) to 98.8 (50.1) µV (p = 0.036) respectively. The treatment produced 2.92% greater reduction in electrical activity of the muscle measured at the end of the experiment compared with placebo. The mean arm circumference of the treatment group increased significantly by 1.8 cm after the supplementation, from 30.87 (1.88) to 32.67 (1.96) cm (p = 0.011), but there was no significant increase in the placebo group. The results suggest that water soluble extract of Eurycoma longifolia Jack increased fat free mass, reduced body fat, and increased muscle strength and size, and thus may have an ergogenic effect. Further investigations are warranted.

Malaysian Clinical Trial On Effectiveness of Tongkat Ali To Boost Sexual Vitality

The following report on a clinical trial on Tongkat Ali effectiveness as an aphrodisiac.

Source: The Singapore Straits Times, Feb 2003.

Early Results Show Men Being becomes More Virile After Taking Tongkat Ali

MEN may stand a better chance of boosting their performance in the bedroom by turning to help from a plant rather than exotic remedies.

Preliminary tests show that Tongkat Ali, an herbal aphrodisiac made from the root of a plant known by the same name, can add to a man's libido and sexual prowess.
Known as Pasak Bumi in Indonesia , Tongkat Ali in Malaysia , and also as Eurycoma longifolia, its scientific, Latin name, the plant grows all over South-east Asia.

Dr. Ismail Tambi, who heads the Human Reproduction Specialist Centre at Malaysia 's National Population and Family Development Board, said that 30 healthy males between the ages of 31 and 52 were given two capsules of Tongkat Ali a day for three weeks.

They reported that their performances in bed had improved - erections were stronger and, in some cases, lasted longer. Overall, they felt more virile.

Their levels of testosterone, the male hormone that plays a significant role in spurring desire and performance, doubled within three weeks. At the same time, the level of another hormone that inhibited sex fell.

It is the root of Tongkat Ali that is made into a drug available in capsule, liquid and powder form.

But Dr. Ismail, who is here for the seventh Asian Congress of Sexology, told The Straits Times that this was just an initial trial.

Starting next year, about 200 healthy males will be involved in a much bigger trial to determine if Tongkat Ali really does the trick.

Malaysians spend about RM6 billion (S$2.8 billion) a year on potions and drugs to enhance their sexual performance and the Malaysian government is planning to invest in a trial that is estimated to cost RM 500,000.

The government wants to determine if this is an industry that can be nurtured and developed.

While there are a few side-effects to using the herbal drug, such as headaches or flushing of the face, these fade away after a few days, said Dr. Ismail.

But he warned that the medication, which is readily available in capsule, liquid and powder form, should be bought from a reputable source.

Abstracts of Scientific Studies and Research conducted on naive male rats to increase sexual motivation with Tongkat Ali (Eurycoma longifolia)

Several tests were conducted on Tongkat Ali as an aphrodisiac plant in laboratories of Malaysia. Below are some important results derived by using Tongkat Ali on different male rats.

Effects of Eurycoma longifolia (Tongkat Ali) on the initiation of sexual performance of inexperienced castrated male rats.

Date: 2001 Oct;
Code: 24(5):437-40
Conducted by: Ang HH and Cheang HS., Yusof AP.
School of Pharmaceutical Sciences,
University Science Malaysia , Minden , 11800,
Penang , Malaysia.

Study objective: Effects of Eurycoma longifolia Jack (Tongkat Ali) on the initiation of sexual performance of inexperienced castrated male rats.

We studied the effects of Eurycoma longifolia Jack, commonly known as Tongkat Ali in Malaysia , on the initiation of sexual performance and the weights of sexual accessories in inexperienced castrated male rats. The doses of 200, 400 and 800 mg/kg body weight, which were extracted from E. longifolia, were orally administered to the rats twice daily for 10 days prior to the tests and continued throughout the test period. Testosterone was used as a positive control after injecting 15 mg/kg daily subcutaneously for 32 days. Results showed that E. longifolia produced a dose-dependent increase in sexual performance of the treated animals, but the E. longifolia groups showed higher sexual performance in mounting, intromission and ejaculation than the testosterone group. Further results also showed that E. longifolia promoted the growth of both ventral prostate and seminal vesicles as compared with the control, but the growth of sexual accessories at 800 mg/kg of butanol, methanol, water and chloroform fractions of E. longifolia was less than that of testosterone treated group. The present study therefore gives further evidence of the folk use of E. longifolia as an aphrodisiac.

PMID: 10803359 [PubMed - indexed for MEDLINE]

Aphrodisiac evaluation in non-copulator male rats after chronic administration of Eurycoma longifolia.

Date: 2002 July
Code: 19B-0.1-(36w)
Conducted By: Ang HH & Ngai TH.
School of Pharmaceutical Sciences,
University of Science , Malaysia ,
Minden , Singapore.

Study Objective: Aphrodisiac evaluation in non-copulator male rats after chronic administration of Eurycoma longifolia.

The aphrodisiac effect of Eurycoma longifolia (0.5 g/kg) was evaluated in non-copulator male rats using an electrical cage. Fractions of E. longifolia decreased the hesitation time of non-copulator male rats, throughout the investigation period. Furthermore, it possessed a transient increase in the percentage of the male rats responding to the right choice, more than 50% of the male rats scored "right choice" after 3 weeks post-treatment and the effect became more prominent after 8 weeks post-treatment (only 40-50% of the control male rats responded to the right choice) using the electrical copulation cage. Hence, this study lends further support to the use of the plant by indigenous populations as a traditional medicine for its aphrodisiac property.

PMID: 11564133 [PubMed - indexed for MEDLINE]

Sexual arousal in sexually sluggish old male rats after oral administration of Eurycoma longifolia.

Date: 2000 Jan
Code: Exp Anim;49(1):35-8
Conducted By: Ang HH, Lee KL, Kiyoshi M.
School of Pharmaceutical Sciences,
University Science Penang , Malaysia.

Study objectives: Sexual arousal in sexually sluggish old male rats after oral administration of Eurycoma longifolia.

Eurycoma longifolia 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, 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 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.

PMID: 15803965 [PubMed - indexed for MEDLINE]

Effects of Eurycoma longifolia on levator ani muscle in both uncastrated and testosterone-stimulated castrated intact male rats.

Date: 2001 Aug
Code: Exp Anim; 15(4):265-8
Conducted By: Fundam Clin Pharmacol Malaysia.

Research objective: Effects of Eurycoma longifolia on levator ani muscle in both uncastrated and testosterone-stimulated castrated intact male rats.

It has been reported that Eurycoma longifolia commonly known as Tongkat Ali has gained notoreity as a symbol of man's ego and strength by the Malaysian men because it increases male virility and sexual prowess during sexual activities. As such, the effects of 200, 400 and 800 mg/kg of butanol, methanol, water and chloroform fractions of E. longifolia were studied on the levator ani muscle in both uncastrated and testosterone-stimulated castrated intact male rats after dosing them for 12 consecutive weeks. Results showed that 800 mg/kg of butanol, methanol, water and chloroform fractions of E. longifolia significantly increased (p<0.05) the levator ani muscle to 58.56+/-1.22, 58.23+/-0.31, 60.21 +/-0.86 and 62.35 +/-0.98 mg/100 g body weight, respectively, when compared with the control (untreated) in the uncastrated intact male rats and 49.23+/-0.82, 52.23+/-0.36, 50.21+/-0.66 and 52.35+/-0.58 mg/100 g body weight, respectively, when compared to control (untreated) in the testosterone-stimulated castrated intact male rats. Hence, the pro-androgenic effect as shown by this study further supported the traditional use of this plant as an aphrodisiac.

PMID: 11693547 [PubMed - indexed for MEDLINE]

Effect of Eurycoma longifolia on libido in middle-aged male rats.

Date: 2002 March
Code: USM-249-54. xNvL
Conducted By: Ang HH, Lee KL.University Science Malaysia , Minden , Penang , Malaysia
J Basic Clin Physiol Pharmacol

Study Objective: Effect of Eurycoma longifolia on libido in middle-aged male rats.

The effect of increasing doses of various fractions of Eurycoma longifolia extracts on libido was examined in middle-aged male rats. The results showed that a high dose (800 mg/kg) of all E. longifolia extracts significantly increased mount frequency (MF) (P < 0.05) over that of untreated controls, but had no effect on the frequency of intromission or ejaculation. Methanol, chloroform, water, and butanol fractions exhibited MF of 2.5 +/- 0.1, 2.6 +/- 0.3, 2.5 +/- 0.1 and 2.6 +/- 0.2, respectively, in adult, middle-aged male rats, and retired breeders versus 2.3 +/- 0.1 in untreated controls. This translated to a minor increase in MF of 8.7%, 13.0%, 8.7%, and 13.0% for these fractions, respectively, during the 20-minute observation period. The results of this study show that Eurycoma longifolia extracts can increase libido in middle-aged male rats.

Source: NATIONAL CENTRE FOR BIOTECHNOLOGY INFORMATION
Website: http://www.ncbi.nlm.nih.gov

Reviews Based on Scientific Research
on Eurycoma Longifolia Jack (Tongkat Ali)

Numerous scientific studies have demonstrated Eurycoma longifolia Jack (Tongkat Ali) effectiveness in enhancing sexual vitality and performance in men. Several publications based on scientific studies & medicinal reviews also reveal Eurycoma Longifolia Jack (Tongkat Ali) effectiveness in increasing muscle strength and size.

From Doctor's Desk: Tongkat Ali Helps Support Healthy Male Sexuality and Arousal.

Dr. Simon Chua,
Department of Pharmaceutical Sciences,
Wayne State University 

In a preliminary study at the Reproductive Research Center in Kuala Lumpur , Malaysia , 30married men, aged31-52 years old, took TONGKAT ALI regularly for three consecutive weeks. Interviews indicated that 48% felt healthy, active and energized, and 40%felt increased sexual desire. The subjects showed an increased free testosterone index. Increased testosterone levels help improve libido, energy and muscle mass for bodybuilding. Their levels of DHEA, another critical steroid hormone, gradually increased from 26%after one week to 47% after three weeks. Most subjects demonstrated increased satisfaction in their sexual health and performance.
In addition, animal studies have shown that TONGKAT ALI may increase testosterone availability as well as libido in mice.

Source: Article from the book Molecular Biology of the Cell,
Published on: Sep 1, 2002

From Doctor's Desk: Tongkat Aki Optimizes Male Sex Hormone Balance.

Dr. James Stoxen
(Article Based on a research conducted by his team of doctors)
Department of Medicinal Chemistry and Pharmacognosy,
University of Illinois, Chicago

The production of testosterone (the principal male-determining sex hormone) falls progressively from age 40. Experts call this "partial androgen deficiency of the aging male." Androgens are steroid hormones with specific effects on tissue growth (muscle, fat, skin, hair and others) and brain function. They play important roles in men and women, but are produced in much larger quantities in men. In men after puberty, the testicles produce most androgens, mainly as testosterone. It has been suggested that Tongkat Ali may block negative feedback to the hypo-thalamus and pituitary glands, so the body continues to produce testosterone at elevated levels.

Source: Chapter 39-a from the book Eureka Bioscience Collection ,
Published on: 3 rd Oct, 2003

Evaluation of the potency activity of aphrodisiac in Eurycoma Longifolia Jack. Contributed by: Ang HH, Ikeda S, Gan EK.

School of Pharmaceutical Sciences,
University Science Malaysia , Minden ,
Penang , Malaysia

The butanol, methanol, water and chloroform extracts of the roots of Eurycoma longifolia Jack were studied using various tests of potency of treated male rats. The results showed that E. longifolia produced a dose-dependent, recurrent and significant increase in the episodes of penile reflexes as evidenced by increases in quick flips, long flips and erections of the treated male rats during the 30 min observation period. These results provide further evidence that E. longifolia increases the aphrodisiac potency activity in treated animals.

Source: Journal index for medicine© 2001 John Wiley & Sons, Ltd,
Published on: Dec 2005.