Over the past few years, there have been quite a number of studies (particularly in rodents) that have tested tongkat ali in relation to sexual effects, with positive results. Here's a detailed discussion of one of them.
The effects of tongkat ali were studied on the libido of male rats after dosing them with up to 800 mg per kilogram of body weight twice daily for 10 days (this is quite a high dose if the same dose is given to humans -- do the math: 800 mg tongkat ali powder times 70 k). Results showed that tongkat ali produced a dose-dependent increase in mounting frequency; that is, the number of times the male rats tried to mount the female rats increased as the dose given to the rats increased. In addition, the rats given tongkat ali displayed more frequent and vigorous licking and anogenital sniffing towards the receptive females. Furthermore, the rats dosed with tongkat ali spent more time grooming their genitals compared to the rats who were not given the plant. Genital grooming may be interpreted as self-pleasuring since the rats were most likely enjoying the sensation of touching themselves. The researchers noticed another interesting finding: while the rats who had not received tongkat ali showed normal behavior within the cage such as exploration and climbing the cage wall, the rats given tongkat ali hung around the females instead of exploring the cage. In terms of the human species, this may be interpreted as a man spending more time in the kitchen helping his wife dry the dishes than in the den half-asleep in a Lazyboy chair with the remote control in the left hand and a can of beer in the right while tuned to ESPN :)
Several studies (see bottom of this page) have tested tongkat ali in rodents to determine whether this plant has aphrodisiac properties.

Tongkat Ali mechanism of action
Little is known regarding the exact mechanisms of action of tongkat ali. Recent studies indicate that the root contains several compounds including beta-carboline alkaloids and quassinoid-type glycosides, including eurycomaoside. How these compounds and many others in tongkat ali influence hormonal release or the human sexual response is not clearly understood (at least by me) at this time. I have read promotional material by some vitamin companies and articles in health magazines that tongkat ali enhances testosterone production or release. Apparently some human trials have been conducted in Malaysia that indicate tongkat ali influences testosterone. However I have not been able to definitively confirm this claim through a Medline search. I would not be surprised if compounds within tongkat ali, such as glycoproteins, do influence blood or brain levels of testosterone. Whether this effect on testosterone continues with prolonged use is not fully understood. I would also not be surprised if compounds within tongkat ali influence sexuality in ways other than just testosterone or hormone effects.

Long term side effects of Tongkat ali
Since long term human trials with tongkat ali have not been published, it would be best to take breaks from use. One option is to take tongkat ali 2 days on, 2 or more days off. Each person is different and will find their own best schedule.
It is somewhat difficult to find the right dose and extract of tongkat ali that works without causing insomnia, and that's where an experienced herbalist who has wide knowledge with this plant is crucial in terms of formulating the right product with the right amount and extract potency of tongkat ali.

Tongkat ali and energy
It is true that tongkat ali increases energy levels, and here again the right dose is crucial since too high a dose will give insomnia, leading to fatigue the next day. However, if you take the right amount which wears off by evening, then you'll be just fine and happy. It is thought that tongkat ali increases energy levels through its actions on ATP.

Tongkat Ali and Cancer
Beta-carboline alkaloids isolated from tongkat ali have demonstrated significant cytotoxicity against human lung cancer (A-549) and human breast cancer (MCF-7) cell lines. In plain English, this means that some compounds in Tongkat ali can kill cancer cells. The practical significance of this finding in humans is not clear at this time.

Tongkat Ali and Malaria
Scientists have found that, in addition to its sex-enhancing effects, compounds within tongkat ali have anti-malarial properties. Some of these anti-malaria compounds are known as quassinoids .

Ecological concerns
Tongkat ali is harvested in the wild and there is a concern that increasing popularity will deplete the natural preserves. Early steps are being taken to cultivate the tongkat ali tree in large plantations.

Tongkat Ali Research Update
Induction of apoptosis by Eurycoma longifolia jack - tongkat ali - extracts.
Anticancer Res. 2005 May-Jun;25(3B):2205-13.
Extracts of the plant tongkat ali have been shown to possess cytotoxic, antimalarial, anti-ulcer, antipyretic and plant growth inhibition activities. The present study investigated the effects of extracts and their chromatographic fractions from the root of tongkat ali on the growth of a human breast cancer cell line, MCF-7. Our data indicated that tongkat ali extracts and fractions exert a direct antiproliferative activity on MCF-7. The bioassay-guided root fractionation resulted in the isolation of three active fractions, F5, F6 and F7, which displayed IC50 values of (6.17+/-0.38) microg/ml, (4.40+/-0.42) microg/ml and (20.00+/-0.08) microg/ml, respectively. The resultant from F7 purification, F16, exhibited a higher cytotoxic activity towards MCF-7, and a certain degree of selectivity against a normal breast cell line, MCF-10A. These results suggest that tongkat ali extract F16 has antiproliferative effects on MCF-7 cells by inducing apoptosis through the modulation of Bcl-2 protein levels.

Sexual arousal in sexually sluggish old male rats after oral administration of Eurycoma longifolia Jack - tongkat ali.
J Basic Clin Physiol Pharmacol. 2004;15(3-4):303-9. Ang HH, Lee KL, Kiyoshi M.
School of Pharmaceutical Sciences, University Science Malaysia , Minden , Penang , Malaysia .
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 tongkat ali, 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 tongkat ali increased yawning by 50% and stretching by 16% 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.

Eurycoma longifolia Jack enhances sexual motivation in middle-aged male mice.
J Basic Clin Physiol Pharmacol. 2003;14(3):301-8.
Tongkat Ali was investigated for sexual motivation activity in adult, middle-aged male mice and in retired breeders. Each mouse received 500 mg/kg of one of 4 fractions of tongkat ali : chloroform, methanol, butanol, and water, whereas the mice in the control and yohimbine groups received 3 ml/kg of normal saline and 30 mg/kg of yohimbine daily respectively for 10 d. The results show a transient increase in the percentage of male mice responding to the right choice after chronic consumption of the fractions with 50 percent of the adult middle-aged male mice treated with tongkat ali and yohimbine scoring the right choice after 8 and 5 days post-treatment respectively. In conclusion, this study has shown that tongkat Ali continues to enhance sexual motivation in adult, middle-aged male mice and in retired breeders.

Effects of Eurycoma longifolia Jack ( Tongkat ali ) on sexual qualities in middle aged male rats.
Phytomedicine. 2003;10(6-7):590-3.
The effects of tongkat ali were studied on the sexual qualities of middle aged male rats after dosing them with 0.5 g/kg of various fractions of tongkat ali whilst the control group received 3 ml/kg of normal saline daily for 12 weeks. Results showed than tongkat ali enhanced the sexual qualities of the middle aged male rats by decreasing their hesitation time as compared to controls. Besides these, there was a transient increase in the % of the male rats responding to the right choice after chronic administration of 0.5 g/kg tongkat ali, with more than 50% of the male rats scored right choice after 2 weeks post-treatment. However, there was no sexual enhancement of the middle aged male rats which consumed normal saline since only 45-55% of the male rats responded to right choice throughout the investigation period. Hence, this study shows that tongkat ali enhanced the sexual qualities of the middle aged male rats, further supports the folk use of tongkat ali as an aphrodisiac.

Effect of Eurycoma longifolia Jack ( Tongkat Ali ) on libido in middle-aged male rats.
J Basic Clin Physiol Pharmacol. 2002;13(3):249-54.
The effect of increasing doses of various fractions of tongkat ali extracts on libido was examined in middle-aged male rats. The results showed that a high dose (800 mg/kg) of all tongkat ali extracts significantly increased mount frequency (MF) over that of untreated controls, but had no effect on the frequency of intromission or ejaculation. Methanol, chloroform, water, and butanol tongkat ali fractions exhibited MF of 2.5, 2.6, 2.5 and 2.6, respectively, in adult, middle-aged male rats, and retired breeders versus 2.3 in untreated controls. The results of this study show that tongkat ali extracts can increase libido in middle-aged male rats.

Effect of Eurycoma longifolia Jack (tongkat ali) on orientation activities in middle-aged male rats.
Fundam Clin Pharmacol. 2002 Dec;16(6):479-83.
The effects of various fractions of Eurycoma longifolia Jack were studied on the orientation activities of the inbred, adult middle-aged Sprague-Dawley rats, 9 months old and retired breeders towards the receptive females (anogenital sniffing, licking, mounting), the environment (climbing, raring, exploration), themselves (nongenital grooming, genital grooming) and mobility (restricted, unrestricted) after treating these subjects twice daily for 10 days. Results showed that subjects treated with 800 mg/kg of tongkat ali increased orientation activities towards the receptive females (anogenital sniffing, licking and mounting), increased genital grooming towards themselves and restricted movements to a particular area of the cage but decreased interest in the external environment (climbing, raring, exploration) as compared with the controls during the investigation period. In conclusion, this study gives further evidences that different fractions of tongkat ali modified the orientation activities of the middle-aged male rats.

Effects of Eurycoma longifolia jack on levator ani muscle in both uncastrated and testosterone-stimulated castrated intact male rats.
Ang HH, Cheang HS. University Science Malaysia , Minden , 11800, Penang , Malaysia .
Arch Pharm Res. 2001 Oct;24(5):437-40.
It has been reported that Eurycoma longifolia Jack 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 Tongkat Ali were studied on the laevator 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 Tongkat Ali significantly increased (p<0.05) the leavator 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 Tongkat Ali as an aphrodisiac.

Aphrodisiac evaluation in non-copulator male rats after chronic administration of Eurycoma longifolia Jack (Tongkat Ali).
Fundam Clin Pharmacol. 2001 Aug;15(4):265-8.
The aphrodisiac effect of Eurycoma longifolia Jack (Tongkat Ali) (0.5 g/kg) was evaluated in noncopulator male rats using an electrical cage. Fractions of Tongkat Ali decreased the hesitation time of noncopulator 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 Tongkat Ali 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 Tongkat Ali plant by indigenous populations as a traditional medicine for its aphrodisiac property.

Eurycoma longifolia (tongkat ali) increases sexual motivation in sexually naive male rats.
Arch Pharm Res. 1998 Dec;21(6):779-81.
The aim of this study is to provide evidence on the aphrodisiac property of Tongkat Ali . An electric grid was used as an obstruction in the electrical copulation cage in order to determine how much an aversive stimulus the sexually naive male rat for both the treated with Tongkat Ali and control groups were willing to overcome to reach the estrous receptive female in the goal cage. The intensity of the grid current was maintained at 0.12 mA and this was the intensity in which the male rats in the control group failed to crossover to reach the goal cage. Results showed that Tongkat Ali continued to enhance and also maintain a high level of both the total number of successful crossovers, mountings, intromissions and ejaculations during the 9-12th week observation period. In conclusion, these results further enhanced and strengthened the aphrodisiac property of Tongkat Ali.

Tongkat Ali Malaria Studies
Antiplasmodial studies of Eurycoma longifolia Jack using the lactate dehydrogenase assay of Plasmodium falciparum.
J Ethnopharmacol. 2004 Jun;92(2-3):223-7.
The roots of Tongkat Ali have been used as traditional medicine to treat malaria.

Cytotoxic and antimalarial constituents from the roots of Eurycoma longifolia (tongkat ali).
Bioorg Med Chem. 2004 Feb 1;12(3):537-44.
Sixty-five compounds were isolated from the roots of Tongkat Ali . Among these isolates, four quassinoid diterpenoids were reported from natural sources for the first time. Screening of cytotoxicity, anti-HIV and antimalarial activity of these isolated compounds was also furnished by in vitro assays. Many compounds demonstrated strong cytotoxicity toward human lung cancer (A-549) cell lines and strong cytoxicity toward human breast cancer (MCF-7) cell lines. Some compounds displayed potent antimalarial activity against the resistant Plasmodium falciparum.

More about Tongkat Ali
Unlike most trees which have a horizontal root system, the root of a Tongkat Ali tree grows as much as one meter straight into the ground. This tough fibrous root penetrates deep into the earth to obtain its nutrients. The Tongkat Ali root takes at least five years to mature. Of an older tree (15-20 years), the root itself can grow to a size that is taller than many people.

Tongkat Ali in Malaysia
In the past, tongkat ali roots had to be brewed for long hours to get a bitter extract. Now tongkat ali, which literally means Ali's cane, is packed in pill or tea-bag form and mixed with regular coffee or tea. Ton gkat ali coffee, tea, and even sodas, are now sold in Malaysia's roadside hawker stalls, supermarkets and even in restaurants at five star hotels.

Previous <<< Articles List >>> Next