It doesn’t matter which sport you follow or what team you support. At some point most of us will come across that one player who, for the life of us, we just can’t see the point of.

They make the squad almost every week, everyone else seems to sing their praises, but as far as you can see they don’t appear to contribute much of anything.

For the life of you, you just don’t understand why they keep getting picked.

In the field of natural testosterone boosting one such controversial pick would be the flowering plant tribulus terrestris. Increasingly a mainstay of various supplements on the market, significant questions still hang over this fashionable ingredient’s effectiveness and basis for inclusion.

Namely: Does tribulus terrestris actually work?

Tribulus terrestris is fairly common throughout the world, occurring in warmer climes such as Africa, South Asia, Australia and the more tropical parts of Europe. It is known more informally in some areas as the ‘puncture vine’ owing to the plant’s tough thorns which are capable of piercing any bicycle wheel unfortunate enough to ride over it.

Indeed the word tribulus is derived from the Latin ‘to tear.’ Plenty of prominent supplements now not only merely include tribulus (or ‘trib’) in some form, but make it absolutely central to their claims of being able to heighten testosterone, help build muscle and invigorate libido.

This must be based on some advances in research shedding light on solid new evidence of genuine effectiveness. Right??

Um, well, not really as it turns out. Compared to several other popular ingredients, trib has been relatively under studied. The results of what little research has been done hardly square with the veritable jamboree given to it by sections of the supplements industry.

In 2007 for example researchers at Southern Cross University in New South Wales, Australia tested trib on twenty four elite rugby players; the men were split in to two groups, one of which was given 450 mg of tribulus terrestris, while the others were given a placebo. Over the course of five weeks, during which their weightlifting performances were monitored, there was found to be no difference between the two sets.

Results later published in Journal of Strength and Conditioning Research stated that trib gave no advantage discernible advantage as far as attempts to build strength or muscle mass or decrease body fat.

Similar results were described in a year 2000 issue of the International Journal of Sports Nutrition and Exercise Metabolism, following tests by a team from the Exercise Biochemistry Laboratory at Iowa State University. Twenty young men were again given a placebo or a supplement containing 750mg of trib and asked to lift weights three times a week for a period of eight weeks.

Once more results showed that the supplement neither raised testosterone nor measurably altered strength.

A year later too, in 2001, researchers from the Human Performance Laboratory at the University of Nebraska gave trib (3.21 mg per kilogram of body weight) to a portion of fifteen healthy bodybuilders, aged 18 to 35. Subjects were asked to perform another standardised weightlifting routine three days a week, specifically designed to work all muscle groups.

At the end of the experiment, trib was found to have contributed in no way to bodily changes, be it muscle gain or weight loss. Both samples had improved strength and endurance to roughly the same extent.

So tribulus is little or no help in improving strength and muscle mass, but what about the declarations that it can be the best thing to happen to your sex life since the work of Barry White? Well unfortunately, what scant evidence there is to support this has largely been obtained through tests on animals.

In 2012 a study found that trib improved sexual activity in what were termed ‘sexually sluggish’ albino lab rats and in a separate experiment a year later tribulus was shown to improve erections in a sample of 8 rabbits, both when the rabbits where given tribulus orally as a supplement, as well as when isolated cells were incubated in tribulus solution.

Being very generous, I suppose you could say that these findings at least indicate that tribulus does something, but in a perfect world there would have to be much more human based clinical testing before we decided trib was useful for something other than an after-hours party in a pet shop.

The fact that there isn’t more research being done into the effects of trib on sex drive, performance or testosterone doesn’t suggest to me that medicine is missing a trick particularly, simply that those white coated boys and girls are smart enough to know when they’ve hit something of a scientific cul-de-sac.

So why is it in so many supplements? And is it safe?

Let’s deal with the latter first; most evidence suggests that trib is not harmful. Certain animal studies in the past have pointed to the possibility of muscle coordination disturbances following ingestion of tribulus in high quantities and one study suggested it may serve to enlarge the prostate, but neither has been proven conclusively.

Likewise there have been reports of bodybuilders developing gynaecomastia – enlarging of the breast tissues – after use, but this symptom is common enough to bodybuilders that it would be difficult to categorically pin solely to trib intake.

The reason why so many men are still taking tribulus is purely down to some supplement manufacturers persisting with the ingredient in spite of a distinct dearth of real evidence that it works.

There are a few of reasons why they might be choosing to do this, none of which exactly cover them in glory.

  1. Firstly and most obviously, if your product’s whole shtick is built on trib and you admit trib is largely discredited, you don’t have a product.
  2. If trib is just one of numerous constituent parts of a supplement, an element which in all probability neither helps nor hinders the user can be handy for padding out components. Often the busier an ingredient list looks the more technical it appears, the more technical it appears the more credible it seems and the more credible it seems, the more likely it is to sell.
  3. It could also be the case that some makers are reluctant to withdraw trib altogether suddenly for fear of causing alarm or raising questions about the legitimacy of other ingredients.
  4. Lastly there’s always the chilling outside chance that some makers – far from just ignoring the research because it may negatively affect their balance – simply don’t know the research, don’t follow it and aren’t interested in it.


The fact of the matter is that any supplement genuinely interested in being healthy and effective will always follow the science. And that science tells us that tribulus terrestris’ reputation should be as shredded as those bicycles tyres which have gone over it in the past.

Treat any product which contains it with suspicion, because there really isn’t anything to justify it’s inclusion.

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