“Natural HGH Release”: Can it be stimulated?
“Does CrossFit Work”; does it provide the epitome of fitness?

“Does Long Jack Work”; Does it improve testosterone levels?

There’s obviously a huge market for men who want to improve testosterone levels. Why else would products with claims of doing so be so conspicuously popping up in cheesy TV and radio ads? They publicize claims of improving libido and solving any embarrassing erectile malfunctions. They carry promises of burning belly fat – of raising energy levels and even potentially improving our golf swings. While a resurgence of ‘T-levels’ could very well contribute to these and other positive effects, it remains questionable whether any presently known ergogenic substances can significantly improve the production of endogenous testosterone.

A popularly marketed supplement for boosting testosterone is a botanical called eurycoma longifolia, or “long jack” for short. It’s extracted from the root of an Asian shrub known as Tongkat Ali. The plant is most prevalent and extensively harvested in Indonesia and Malaysia where its extracts have long been used for aphrodisiacal purposes. This historical use would certainly bode well for its prospects as a possible sex hormone enhancer.

Dep_5313922-Tongkat-ali-jackSo the question is…“does long-jack work”; can it increase testosterone?

By merely taking the words of its marketers at face value, you’d think the stuff reverts all middle-aged men back to their testosterone-driven, pimply-faced, pubescent versions of themselves – complete with spontaneous “arisings” every few minutes that simply come from frequent and random sexual thoughts (not sure I’d want to go back to that again).

A few rodent studies show evidence that the “does long-jack work” question can be answered in the positive; it’s boosted the testosterone of some lab rats. Anecdotal feedback is mixed, however, suggesting the question “does long-jack work” should be answered with the qualification of it depending heavily on product quality and dosage. Adding to the well-advised idea of keeping a healthy skepticism about such products is the discovery that there are companies selling bogus versions of Tongkat Ali extract. Imagine that – as if it hadn’t too long been a common theme in the “hormone boosting” supplement niche for people to knowingly sell stuff that doesn’t work.

With the questionable scruples of a good many supplement companies as our backdrop, let’s delve a little deeper in our investigation of the “does Long Jack work” question.

‘Does Long Jack work?’ Maybe… at a hefty dosage

A study of male rats done in Penang, Malaysia demonstrated the aphrodisiacal effects of eurycoma longifolia. Researchers gave the middle-aged rodents various fractions of ‘long jack’ at 0.5g/kg of bodyweight for 12 weeks as compared to a control group that received a dosage of saline.

So what were the results; does long jack work?

To put it in slang vernacular, the rats receiving the ‘long jack’ turned into some “horny old goats.” Whether this was due to significantly increased testosterone levels was not tested or documented, but one can surmise this to be the case.

It should be noted, however, that the rats received quite a hefty dosage – equivalent to a 170-pound man ingesting almost 40 grams daily of ‘long jack.’ To put this in perspective, notice that the typically marketed product claiming to contain “potent” dosages of ‘long jack’ list amounts of 300 mg to 500 mg on their labels. Assuming these products have actual Tongkat Ali extracts in them, a person would need to consume 80 to 130 capsules per day to get the dosage the rats received. Whew… expensive! Since these marketers recommend taking 3 or 4 capsules of their products per day, they’re not even in the ballpark of caring whether their products are consistent with study results.

An Italian study at the University of Modena had a similar finding. In this study, rats showing different levels of “sexual sluggishness” were given Tongkat Ali root extract (long jack) for 6 to 12 days. The rat’s testosterone levels increased and so did their “mounting behavior.” Even the rodents that had been sexually impotent became motivated and sexually active due to the testosterone-boosting effects of something in the plant’s extract. However, this occurred with similar dosages of 500 mg./kg. of body weight. Again, to put this in human perspective, it would be relative to a 200 pound man consuming about 45 grams of ‘long jack’ per day.

The question is: Does ‘long jack’ work in humans at lower dosages than were used in rodent tests? According to anecdotal evidence… “yes”, but a measurement of extract strength comes into play.

‘Does Long Jack work?’ Maybe… at the right extract ratio

To make the “does long jack work” question just a little more complicated, it can only be answered with consideration of the strength of extract in the product. That makes sense since the active ingredients are separated from a plant root that has many other properties. Consequently, Tongkat Ali extract (‘long jack’) comes in strengths of 1:50, 1:100, 1:200. These ratios indicate the amount of root that was used to boil out the extract. A 1:50 ratio means that 50 grams of root were used to remove each 1 gram of active extract. Obviously, the most potent products would be those containing a 1:200 ration; 200 grams of Tongkat Ali root to obtain each one gram of extract.

Machine_Pulley_CurlsThe staunchest advocates of ‘Tongkat Ali’ recommend staying away from any products with labels depicting ‘LongJack’, ‘Tongkat Ali’, or ‘Eurycoma Longifolia’ without specifying the ratio of the extract. That makes sense; since the ratio is important, withholding this information would seem an obvious practice to avoid for proving the reputability of the product based on the ingredients therein. Regardless, many products on the market simply have Eurycoma Longifolia listed as an ingredient among others on the label. This is almost a guarantee that the ‘longjack’ in the product will have little or no effect.

Another factor in answering the “does long jack work” question is product quality. Again, the anecdotal evidence provided by those who’ve used the extract and stand by the claim that it raises testosterone provide rules-to-live-by with regard to this. They say that only extracts from plants of ten years or older are effective. They assert that the active ingredients must be painstakingly boiled out of large amounts of the plant roots as opposed to the root powder being merely extracted and stuffed in capsules along with cellulose fillers.

Something of high importance along with the “does long jack work” question is product safety. Tongkat Ali plants only grow in certain parts of South East Asia. That’s where it’s harvested and where product manufacturing takes place. Of the two countries that grow most of it (Malaysia and Indonesia), it’s said that Indonesian sources are the best choice. This is because there've been allegedly potentially dangerous levels of mercury detected in Malaysian Tongkat Ali.

‘Does Long Jack work?’ Maybe… if the source is reputable

Of considerable importance in the “does long jack work” question are the many counterfeit versions of the product. The demand for real Tongkat Ali is greater than supply, making it an expensive supplement. For this reason as well as the intrinsic remoteness of the plant sources, it’s a prime asset for fake versions. Since any ‘long jack’ counterfeiter can bet on both price sensitivity and inaccessible product verification among a big segment of the market, a huge potential exists for price undercutting with large margins. This is the textbook scenario for a substance to have a larger-than-normal percentage of counterfeit varieties.

That would likewise make eurycoma longifolia a prime object for false negative feedback. If the question “does long jack work” can be answered with a “yes” only in the case of real aged root extracts being used in high enough doses, then the threshold for adequate product potency is high. Anything short of this standard would likely be ineffective. If the stuff actually can increase testosterone, one has to wonder how many product triers many have concluded otherwise due to fake or inadequate product potencies.

I’d love to get feedback (positive or negative) from readers who’ve used ‘Long Jack’ for muscle building, libido enhancement, or health benefits. Your comments are appreciated.



I have tried tongkat capsules. I used 2-3 300 mg (1:200 ratio) capsules daily. They unquestionably had effect. After about a month I noticed reduced fat ratio and increased muscle mass, abs got more defined. Scientific studies have also indicated increased lean body mass compared to placebo in trials.
It should be cycled with 5/2 weeks on/off cycles for best result. Only undesirable side effect I noticed was somewhat increased acne. It is very important to check up source/supplier for good quality extract before buying.


Great article.. i enjoyed reading your article ... thanks for sharing your article...


Hello Dai,

Thank you for the kudos on my article.

I take it you've never tried the supplement that's the topic of the article? I'd love to hear any honest feedback from anyone who's tried Tongkat Ali. I personally haven't.

I think 'Grape Seed Extract' can indirectly raise free testosterone levels. Although it's never been extensively researched for this effect, it has been shown to be an aromatase inhibitor. This means it can reduce the conversion of testosterone to estradiol, which leads to higher net testosterone levels.

I've heard and experienced anecdotal evidence to support this. At relatively high doses (at least a gram daily), I've noticed my bodybuilding gains improve.

I should probably mention, however, that I would not recommend or dissuade anyone from using high doses of Grape Seed Extract. Nobody knows if there are long term side effects. I can only say that I've never experienced any, and I've taken a lot of it. Back in the late nineties, I briefly worked for a buddy of mine who marketed it. He'd show his appreciation by throwing a case my way every once in a while. I wound up with such a high personal inventory that I just ended up taking a handful of the capsules three times a day.

A lot of older guys who used it said they noticed more "unhindered activity down there" (to put it very prudishly :-)

Please drop by again when you get a chance.


Great article. A question for you Scott is there a reliable supplement out there to boost testosterone. Being a guy in my fifties naturally my testosterone is lower than what is was as a young man and, wanting to get the best bang for my buck working out. I would like to know if there is an effective and reliable testosterone booster that actually does what it says it will do.

Is there such a product (supplement) without going to see the doctor?

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