Call me a stickler for ‘truth in advertising.’ Or just count me as someone who gets annoyed by all the brazen claims made about “testosterone boosting” supplements that get bandied about in the name of selling product at the expense of unsuspecting newbie bodybuilding consumers. When addressing the question “does Tribulus work”, the image that gets under my skin is that of online videos in which bodybuilding supplements resellers sit at a table and “review” some well-known bodybuilding pills, powders, and potions. These guys will shamelessly display a bottle of Tribulus Terrestris and with nary an acknowledgment of the very legitimate question “does Tribulus work”, they’ll tell you “how” it works with a straight-faced assumption that it does. It’s as if any positive claims that were ever presumed about a product, whether hypothesized or even purely imagined, are repeated as fact if that’s what’s expedient for the supplement sellers. I’ve just heard a couple of them repeat the following worn-out claim:
“Tribulus works to raise testosterone levels by increasing luteinizing hormone to the testes.”
But the question “does Tribulus work” has never been definitively answered within the realm of human studies. In fact, some research suggests that it has no positive testosterone-boosting effect in healthy human males at all. Apparently, this doesn’t stop some supplement hawkers from assuming the animal studies are positively conclusive and ripe for extrapolating that tribulus will increase T-levels in humans. Evidence doesn’t support that assumption. Keep this in mind the next time you’re browsing bodybuilding supplements and a store clerk tells you “tribulus raises testosterone”… as if it’s fact.
‘Does Tribulus Work’: What do the studies show?
There are two likely reasons why a guy might be interested in the “does tribulus work” question: 1) He’s a bodybuilder or athlete interested in raising endogenous testosterone levels for greater strength and muscle gains. 2) Suspected low testosterone levels have caused a flagging libido that he wants to regain. In either case, if tribulus has significant positive effect on raising testosterone, the effects should be anecdotally measurable. And in the case of reason number one, a heightened libido would likely be the acute effect en-route to better muscle gains if tribulus did trigger any significant increases in testosterone.
The notion that extracts of tribulus terrestris (a flowering plant of Europe, Asia, Africa, and Australia) can boost testosterone levels is supported by evidence of animal studies. The most prominently cited of such studies seems to be one done by Gauthaman K, Adaikan PG, Prasad RN, in 2002 and published right here in PubMed. The researchers sought to determine whether tribulus terrestris possesses aphrodisiac properties in castrated rats. They divided the rodents into five groups of eight subjects each and tested them for eight weeks. Two groups (one castrated and one “intact”) received distilled water (a placebo). Another two groups (one castrated and one intact) received doses of testosterone (10 mg/kg body weight). The fifth group was castrated and received 5mg/kg bodyweight of tribulus terrestris. All the rodent’s body weight and prostate weight were measured, along with measurements of six sexual behavior parameters.
So what were the results; “does tribulus work” as an aphrodisiac in rats?
“Statistical significance” from this study showed that it does. As expected, all groups of castrated rats showed decreases in body weight, prostate weight, and sexual behavior. However, compared to the ‘control group’ (placebo) of castrated rats, both the testosterone and tribulus treated groups of castrated rats showed slight increases in body weight, prostate weight, and sexual behavior. The researchers concluded that the increase in these parameters among the tribulus terrestris treated rodents was probably due to aphrodisiac activity from the plant’s androgenic properties.
It might be worth noting that the dosage of tribulus terrestris given to the rats in this study was not excessive; equivalent to about 400 mg. daily of tribulus for a 180-pound man.
The few human studies done on tribulus terrestris, however, do not substantiate the findings of animal research done on the plant. One such study was performed on twenty-one young men (ages 20-36) in Bulgaria and published in the Journal of Ethnopharmacology. In this experiment, the men were divided into three groups of seven subjects each. One group was given 10 mg/kg of bodyweight of tribulus terrestris. A second group of seven guys was given 20 mg/kg of bodyweight of tribulus. The other seven (the control) was given a placebo. The groups were tested for four weeks with the experimental subjects taking three even dosages per day of their respective amounts of tribulus. Measurements of the test subject’s serum testosterone, androstenedione, and luteinizing hormone were taken before supplementation began – four times during the experiment – and once at the conclusion of the four weeks.
So what were the results; “does tribulus work” for boosting luteinizing hormone and testosterone levels in twenty and thirty-something-year-old-guys?
Well, not according to that experiment. It showed no statistical significance at all between the guys that got the tribulus and the ones who got the fake pills.
Another human study, this one done on elite rugby players in Australia, sought to determine if tribulus terrestris would improve testosterone levels and strength gains within a five week period of supplementation. The twenty-two subjects were divided into two groups of eleven. One group received one daily dosage of 450 mg. of tribulus while the control group received a placebo. Both groups underwent their usual pre-season heavy weight-training regimen while the researchers monitored their strength gains, muscle gains, and urinary testosterone/epitestosterone (T/E) ratios. An increase in this ratio would be the easiest way of determining if testosterone levels have risen significantly.
So what were the results; “does tribulus work” in improving ‘T-levels’, strength gains, and muscle gains in elite male athletes?
It didn’t in this test. Although all the subjects gained strength and muscle from their workouts, there were no significant increases among those using tribulus versus those taking the placebo. Furthermore, researchers found no increase of the T/E ratio in the tribulus-taking group.
Are the studies cited here (among a few others) conclusive in answering the question “does tribulus work?” Hardly; the question seems worthy of bigger and better studies with higher dosages of this supplement. All I can do for now is provide my own anecdotal feedback about high dosages of the most purportedly concentrated and “potent” tribulus terrestris on the market.
‘Does Tribulus Work’: Is it just a ‘concentration’ and ‘dosage’ thing?
Some people insist that tribulus terrestris really is effective at raising testosterone if only taken at a potent concentration and high enough dosage. I’m willing to accept this hypothesis, while currently only inclined to expend the resources to test it anecdotally, not scientifically. I’d love to see better-controlled and bigger human experiments done on this product. For now, however, I’m relegated only to personally testing the “hottest” tribulus product every few years – usually when a company claims to have maximized the dosage and percentage of ‘steroidal saponins’ within the product.
Just such a new tribulus product was recently released on the market. It’s called Trib X 90, and it’s purported to contain 90% saponins in each of the 750 mg. capsules. Saponins are what’re believed to be the active ingredients in tribulus terrestris, and I’d only ever seen a maximum percentage of 45 until this product came out. Wow, it’s got double that amount. If tribulus works to raise testosterone in high dosages of potent concentrations, this stuff should deliver the goods.
And I didn’t “test” it in a sparing manner. I went all-out and took up to 6 capsules of Trib X 90 per day. That’s going as high as 4.5 grams of daily intake of tribulus. Of course, I started out with two capsules per day and built up slowly to that max dosage to be sure my body didn’t have a negative reaction to large amounts. I took 2 capsules per day for one week – 4 capsules per day for the second week – and 6 capsules per day for another eight days. This got me through the entire contents of the 90-capsule bottle in just a little over three weeks.
By-the-way, my decision to test this stuff on myself at high dosages was personal; I’m not recommending that anyone reading this should do the same. And be sure to consult your physician before making the decision to use the product (at any dosage) yourself.
So what were my results; ‘does tribulus work’ anecdotally (for me) at high dosages of maximum concentrations?
That’s a negative. I experienced no tell-tale effects of “jacked-up” testosterone. The only physiological effect I noticed was a temporary increase of an “antsy-like” energy… but no different than what I might have gotten from a daily dosage of 5-hour energy drink.
Proponents of tribulus terrestris might argue that ‘increased energy’ was a positive effect of higher testosterone. Maybe… I can’t say for sure because I didn’t have any blood tests done before or during the time I used the product. What I can say for sure is that my muscle building progress derived from a unique and already extremely effective training system remained the same. Also, I noticed no sudden jump in libido from this very high dosage of tribulus.
Admittedly, I have no way of knowing if there’s truth-in-labeling being practiced by the company whose tribulus product I used. Also, I admit to ‘testing’ it for a relatively short period of time with the notion that it should begin showing results in three weeks if it ever would at all.
Does tribulus work? My personal recommendation is that people not waste their money on this stuff. There’s too much evidence showing that even if you get some benefits from the product, they won’t be nearly commensurate with the monetary costs.
In conclusion, I would love to hear feedback and opinions on the “does tribulus work” question. Your comments are welcome and encouraged.