The Right Chemistry: Is Tongkat Ali root 'nature's Viagra'? Don't bet on it

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Joe Schwarcz, Special to the Montreal Gazette

Published on: November 27, 2014 | Last Updated: November 27, 2014 5:34 PM EDT

Talk about getting to the root of the problem. Literally.

The “problem” is decreased libido, and at least according to Chris Kilham, a.k.a. the “Medicine Hunter,” the answer may lie in the root of the Tongkat Ali tree, native to Malaysia and Indonesia. Kilham has forged a career searching for medicinal plants on behalf of herbal supplement manufacturers, but his biography is silent about his educational background. It does play up his books, which promote the benefits of cannabis, acai berries and dragon’s blood, as well as his frequent television appearances, especially on the Dr. Oz Show, which is not known for selecting guests based on scientific expertise.

Kilham tickles the fancy of interviewers with his interest in psychoactive and psychedelic plants like kava and ayahuasca, but it is talk of substances that may provide a boost in the bedroom that garners widespread publicity. Kilham opines that “when you give people Tongkat Ali, it’s Chinese New Year in their pants.” And the companies he works for like the fireworks idea, too. Naturex is rolling out a “quality” extract of Tongkat Ali root that it claims is a “natural, easy and affordable way to regain your manhood,” and at least in the eyes — and apparently other body parts — of one satisfied woman featured in an ABC Nightline interview, your womanhood as well.

There is no doubt that Tongkat Ali is destined to get a chunk of the multi-billion dollar sexual dysfunction market, but will it deliver the goods?

Various extracts of the roots of Eurycoma longifolia, the tree’s proper botanical name, do have a history of folkloric use for the treatment of malaria, fever, fatigue, high blood pressure, impotence and loss of sexual desire. But folklore is not scientific evidence. For such, we look to PubMed, a listing of published papers catalogued by subject and author. There are numerous studies exploring the properties of Tongkat Ali, just as there are for all sorts of plants with reputed medicinal uses. Over 100 compounds have been isolated from the tree’s root and their molecular structures determined. Quite an achievement! Many were found to have some biological activity in vitro, meaning in laboratory studies using cultured cells. Some extracts were reported to prevent the multiplication of breast cancer cells, others inhibit the activity of the parasite that causes malaria. Nothing unusual here, thousands of plant-derived compounds have biological activity in the laboratory without ever proving to be of any clinical value. Now, what about the supposed aphrodisiac effect?

A number of studies have explored this possibility, but almost all involved animals. Rats have been shown to increase their ano-genital sniffing activities, as well as their mounting frequency. Castrated males increase their sexual activities when given an oral extract, but not as much as when treated with testosterone. E. longifolia extracts also “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 treated males during a 30-minute observation period.” I’m not sure what a “quick flip” of a rat penis means, or whether this would be a desirable trait for a man. Another study showed a 20-per-cent increase in libido after 10 weeks of supplementation with an herbal extract that included E. longifolia. The problem is that the study was carried out with boars.

Now let’s see what’s up with people. Actually, not much. Chris Kilham ballyhoos the work of Dr. Johari Saad “who is called by many the King of Tongkat Ali” and has carried out “painstaking research” to show that the use of Tongkat Ali root extract significantly increases testosterone production. Apparently it was also too painstaking to publish the research, because no reference to it or to Saad is to be found on PubMed. Only two human trials are listed, both of which show a measurable increase in testosterone levels, with one claiming an improvement in muscle strength as determined by a handgrip test, the other finding that men taking an extract had fewer complaints according to the Ageing Males’ Symptoms Scale, a standardized rating scale. Not exactly the evidence needed to turn Tongkat Ali into a blockbusting drug, a “household name,” as Chris Kilham hopes. He is in fact willing to stake his reputation on what has been referred to as “nature’s Viagra.” I don’t think I would do that.

Joe Schwarcz is director of McGill University’s Office for Science & Society ( He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.


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