Devil's Weed: Tribulus Terrestris
The Latin name Tribulus terrestris sounds like an earthy Roman emperor. Some people think it rules among muscle-building supplements. Others argue that this 'emperor' has no clothes. Let's see if this is the supplement to give you pecs of a Roman breastplate and cobblestone abs.
Thorn In Your Ride
Tribulus provides native ground cover to many parts of the world. You probably know it by one of its more ominous-sounding nicknames: Puncturevine, Goat-head, Cat's head or Devil's weed. The flowering fruits of this little herb dry out in late spring and harden to form small, spiked seeds. Mountain bikers or hikers with dogs in the Western United States can thank Tribulus for flat tires, the need to buy thorn-resistant tubes, or constantly pulling thorns out of Fido's paws.
Like all herbs, Tribulus contains many active ingredients. However, its saponins - specifically the steroidal saponin protodioscin - is currently believed to be the principal active nutrient derived from Trib.
Test ... Check One, Two
Tribulus has mainly been used as an herbal testosterone booster, or included in formulations to promote increased muscle mass or strength. For example, when researchers from Lithuania recently provided athletes 625 milligrams of a 40%-saponin-containing Tribulus three times per day for 20 days, they reported that circulating testosterone increased significantly during the first 10 days of the experiment. However, it didn't rise further for the remainder of the study.
If Tribulus does affect testosterone levels, it might do so by increasing luteinizing hormone (LH) or follicle-stimulating hormone (FSH). Another explanation to any rise in testosterone could be that it happens as a secondary response to Tribulus' ability to significantly reduce blood glucose.
Can You See The Difference?
Aside from a few animal studies that have reported increased body weight in response to Tribulus, the limited human data that has been collected hasn't provided clear evidence that Tribulus improves body composition or strength beyond that of a placebo. The caveat, though, is that the dose was likely too low in both studies that have been conducted.
Tribulus is an herb, but it varies from species to species. Just like how wines produced from the same species of grape but grown in different parts of the world will differ, perhaps significantly, all Tribulus herbs/products can't be assumed to be identical.
In this case, protodioscin concentration - which basically tells you how powerful the Tribulus may be - depends on where in the world it was harvested, and what part of the plant was used. The highest concentrations tend to come from Turkey, Macedonia and Bulgaria. Materials from India, China and Vietnam have reported significantly lower concentrations.
Get The Right Stuff!
If Tribulus raises natural testosterone levels, its effects appear to be dose-specific. In other words, the delivery of active protodioscin seems to be effective only within a tight range. Too little or too much, and it doesn't appear to work. The sweet spot seems to be consuming enough Tribulus so you get between 2.3 and 4.6 milligrams of protodioscin per pound of bodyweight per day.
Look for a Tribulus terrestris extract that's standardized to no less than 6% protodioscin and between 40% and 45% total saponins. Again, ideally, the plant from which the supplement is derived will be sourced from Turkey, Macedonia or Bulgaria.
My theory is that if Tribulus increases circulating testosterone, then it probably does so secondary to promoting blood glucose disposal. I recommend taking Tribulus on an empty stomach with water only or a zero- or very-low-calorie drink. On training days, consume one dose when you wake up in the morning, and another prior to training. On non-training days, consume the second dose mid-day. You could consume Tribulus with meals, but I'm more prone to believe that Tribulus works best when blood glucose is at the low end of your normal range.
Herbal Buddy System
Tribulus is commonly stacked with other herbal testosterone supporters, anti-estrogens, cortisol blockers and the like. Personally, I like to keep it simple: Tribulus plus D-Aspartic Acid, Coleus forskohlii, Phosphatidyl Serine and Vitamin D3. If you're 35 or older, add 200 milligrams of DHEA. Sure, there are a ton of other gadgets on the market you could add. Some of them are very cool, and new ones bubble to the surface all the time. But I've never been a fan of the kitchen sink formulations that use too little of too many ingredients.
On Again, Off Again
Some researchers suggested that Tribulus may be what's called an adaptogenic herb. Since adaptogens generally only elicit a significant response while they're working to bring your body back into balance, it may be wise to cycle on and off Tribulus as you would any other adaptogen. For example, you might supplement with Tribulus during periods of extremely intense training or dieting and then cycle-off during recovery phases.
Sexy, Smart And Dizzying
As with any ingredient that might affect blood glucose disposal, you could experience some shakiness or light-headedness if you're extremely sensitive to changes in the amount of glucose present in your blood. Also, if you do experience increased testosterone levels, common side effects are an increase in mental acuity and alertness.
Not Enough Evidence
The data on Tribulus is still inconclusive, but remains promising. The current shortcomings may simply reflect a lack of research to dial-in the correct dosing and dosing conditions to optimize the response. Only time will tell.
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This article is indeed very helpful. I was not sure when I wanted to order this product given many comments, which actually had divided opinions. Though I have already placed the order yet I got more convinced after reading the article. However, I don't agree that Tribulus has an effect on testosterone surge secondary to glucose disposal. This is something unlikely and requires more facts. I say this given my experience in glucose biology.
@atult. My hypothesis on the secondary nature of Tribulus' effects on testosterone is due to the data that has shown a Tribulus to be a hypoglycemic, possibly attributable to an insulinotropic effect on pancreatic beta cells or reduction in hepatic enzyme activity, and the research that has found testosterone levels to be inversely related to blood glucose (Clin Endocrinol (Oxf). 2011 May;74(5):572-8.). However, I'm always interested in learning and don't claim to be an expert in anything other than not being an expert in anything, so I'd love to hear your thoughts on the topic. Thank you - chris
@lostchiekurs. I hope you're referring to Tribulus and not my writing :)
Seriously, I hear that alot with many herbs, so I do genuinely get where you're coming from. My opinion, fwiw, is that herb standardization and the number of "formulation experts" that know little more than poor marketing is what has hurt the herb category's credibility and has led to ingredients such as Trib getting a bad wrap...or ingredients like Ma huang getting pulled from shelves. I always like to compare it to wine - few would argue that a wine from Alabama is not going to be the same as one from Central California; however, most people see an herb for sale and generally think they're all the same except for price. Rain, soil conditions, season of harvest, extraction methods used, etc, all effect an herb's potency just as those same conditions affect the taste of wine.
Regardless, thank you for reading the article. - chris
Another thing to remember is that Trib only brings T levels to high normal, so you are not going to notice any ridiculous strength gains in the gym especially if you are already in high normal range. There is a reason Tribulus is still around after all these years, mainly because of it's saftey, it's effectiveness, and lack of negative sides.
Chris, Great article, very informative. 200mg of DHEA seems a little much though. I have used 50mg DHEA, 625 -725mg Tribulus stack as well as each one alone. From my experience, DHEA brings T levels to above normal but is very suppressive to natural T production. Tribulus on the other hand brings T levels to high normal but doesn't shut the user down. Do you really use 200mg DHEA? Do you experience shut down at all once you stop taking the DHEA?
I got great results off the DHEA Trib stack but have not used DHEA since because of the negative sides ie, acne and shut down. I have continued to use Trib though and to all of the people who say "it's a waste of money" all I can say is it definately works for me, I've been using it for over 10 years with not negative side affects at all.
@dnice60: You're correct, that there's good evidence that DHEA can also negatively impact T:E ratios. However, there's also good evidence that, for some older adults, 200mg DHEA is what's necessary to increase T back to healthy levels. Once normal levels are achieved, a maintenance dose of 25-50mg/d is all anyone would need.