What the Research Says about Longjack:
Aphrodisiac - Over the past few years, there have been quite a number of studies that have shown longjack to have sexual boosting properties. The effects of longjack 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. Results showed that longjack 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 displayed more frequent and vigorous licking and anogenital sniffing towards the receptive females. Furthermore, the rats dosed with longjack spent more time grooming their genitals compared to the rats who were not given the plant. Genital grooming may be interpreted as masturbation. The researchers noticed another interesting finding: while the rats who had not received the plant showed normal behavior within the cage such as exploration and climbing the cage wall, the rats given tongkat ali stayed around the females instead of exploring the cage. Longjack also increased the frequency of the rats' erections.

Longjack and Cancer treatment
Beta-carboline alkaloids isolated from longjack, have demonstrated significant cytotoxicity against human lung cancer (A-549) and human breast cancer (MCF-7) cell lines.

Longjack and Malaria
Interestingly, scientists have found that, in addition to its sex-enhancing effects, compounds within longjack have anti-malarial properties.

Longjack Mechanism of action
Very little is known regarding the mechanisms of action of longjack. Recent studies indicate that the root contains several compounds including beta-carboline alkaloids and quassinoid-type glycosides. How these compounds and many others in Tongkat Ali influence the human sexual response is not clearly understood at this time. I have read promotional material by some vitamin companies regarding longjack that it enhances testosterone production, however I have not been able to definitively confirm this claim through a Medline search.

Longjack Availability
Tongkat ali is sold as a powder, and in capsules, sometimes mixed with other herbs. There are a number of extracts available in various potencies, and since each company will have a different way of extracting, it is difficult to give dosages that would be consistently effective.

Longjack Side Effects
High doses of longjack cause insomnia and increased body temperature along with rapid heart beat. Long term effects on human consumption are not known.

Longjack supplement questions
Q. Shen Min product contains zinc, selenium, saw palmetto, pumpkin extract, quercetin, He Shou Wu, Kudzu extracts, soy extract, tomato powder. Do any of these ingredients cancel the sexual effects of Longjack supplement?
   A. We are not aware of any studies that have evaluated Longjack tongkat ali supplements in combination with any of the ingredients present in Shen Min. Our best guess is that longjack would still have a pro sexual effect. We suggest to first learn how each product works by itself before combining.