Tribulus terrestris (family Zygophyllaceae, order Zygophyllales) is a well-known herb often used in Ayurveda, a form of traditional Indian medicine. It’s been used traditionally to promote male virility and sexual health but has also gained popularity in bodybuilding circles due to the claim that it raises testosterone levels.
The herb grows in dry, hot regions all over the world, including Africa, North America, Australia, and southern Eurasia. The main appeal of Tribulus terrestris is that it’s a cheap herb that’s readily available from a variety of regions, and it’s natural.
As a natural herb, it is expected to have fewer side effects than using steroids or similar drugs. Tribulus is one of the first fitness supplements to be marketed as a natural testosterone booster, though evidence to support this claim has been scarce.
Does Tribulus Increase Testosterone?
The central claim made by many advocates for Tribulus terrestris supplements is that it can raise testosterone levels naturally. One of the main active ingredients in tribulus is a compound known as protodioscin, which increases the secretion of luteinizing hormone (LH).
LH is a gonadotropic hormone which controls the function of the ovaries in females and testes in males. An increase in luteinizing hormone should then also result in an increase in testosterone production in men.
The second proposed mechanism of action for tribulus is that it has a mild inhibitory effect on the 5-alpha reductase enzyme. Tribulus could prevent the breakdown of testosterone by inhibiting 5-alpha reductase, increasing overall testosterone levels in the body.
So while this sounds great in theory, does tribulus actually boost testosterone levels? The answer seems to be no. There have been many studies done on the herb in humans, and most of them seem to suggest that Tribulus terrestris has no impact on androgen production in normal men.
It’s not all negative, though, as there is at least one study that shows an increase in testosterone in men with partial androgen deficiency when taking a Tribulus terrestris supplement. (1) However, the overwhelming evidence points to the fact that, no, tribulus doesn’t increase testosterone levels to any notable degree in healthy active men.
Tribulus Terrestris and Bodybuilding
Many supplement manufacturers claim that tribulus works by increasing endogenous testosterone levels in the body, helping you build and retain muscle more efficiently. Since athletes and bodybuilders are the target market for tribulus supplements, many of the human studies have focused on this group of people, but the results have been less than overwhelming.
To date, there is no real evidence to show that tribulus supplementation can improve muscle mass. For example, in one study tribulus did not appear to affect the muscle strength or body composition in a study of rugby players and young men. (2)
While the link between tribulus and testosterone is generally weak, there are still other mechanisms by which tribulus can help bodybuilders achieve their goals. A study of 15 boxers found that while Tribulus terrestris extract didn’t change muscle mass or increase testosterone production, it did alleviate muscle damage and promote anaerobic performance. (3)
It’s important to note that this is just one study and that the results haven’t been replicated anywhere else.
Does Tribulus Help Treat Erectile Dysfunction?
There is one study that looked at older men with partial androgen deficiency (PDAM) and the impact that Tribulus terrestris had on their testosterone and LH levels, as well as on erectile function. The researchers found a statistically significant difference in erectile function and free testosterone levels in the men who took tribulus 3 times a day for three months. (4)
Another study included 180 men between the ages of 18 and 65 years with mild to moderate ED. Participants with ED and hypertension, diabetes, and metabolic syndrome were also included in the study.
Each participant took tribulus three times per day over a 12-week period. At the end of the study, the men reported a significant improvement in sexual function, quality of orgasm, and sex drive. (5)
However, a more sophisticated study that used double-blind testing on a group of 30 healthy men found that a Tribulus terrestris supplement was not effective at improving symptoms of erectile dysfunction. (6) However, this study only lasted over a period of 30 days, which suggests that tribulus needs to be supplemented for a longer period of time to experience its full benefits.
Besides the potential benefits to health already mentioned, Tribulus terrestris may also provide several other positive effects, including:
- Normalizing blood sugar
- Preventing damage to blood vessels
- Maintaining healthy cholesterol levels
- Diuretic ability
- Improving immunity
- Supporting prostate health
- Anti-depressant properties
- Anti-inflammatory effects
- Providing pain relief
- Potential anti-cancer effects
The recommended dosage of tribulus is between 10 and 20 mg per kg (or 4.5 to 9 mg per lb.) of body weight per day. (7) For example, an individual weighing 185 lbs. (or 84 kg) would take between 840-1680 mg per day.
The total doses should split across three times per day, ideally between meals.
While you can get tribulus powder, it basically tastes like wet grass mixed with mud… so, not that great. As an alternative, you can take it in capsules that are produced by supplement manufacturers and stick to their guidelines regarding dosage.
What Are The Side Effects of Tribulus?
Tribulus has been used safely in research studies lasting up to 3 months, and there have been very few mentions of adverse side effects.
While unlikely, some people have reported mild side effects such as gastrointestinal distress, jitteriness, trouble sleeping, or heavy menstrual bleeding in women. In some rare instances, reports of kidney damage have been associated with tribulus supplementation. It’s not known what the long-term safety of tribulus might be.
While there are some uncommon exceptions, it is thought that tribulus is generally safe to take at the dosages mentioned above. If you are taking any other medication, it’s always a good idea to consult with your physician before starting a new supplement.
Since some supplements can interfere with medicines in surprising ways, it’s best to get the green light from your doctor before experimenting on yourself.
In general, some of the claims made by Tribulus terrestris supplement manufacturers aren’t really supported by scientific evidence. While some studies suggest tribulus supplementation does have an impact on testosterone production, these studies were performed in older men with low testosterone counts.
In studies where the subjects were healthy, athletic men, tribulus was shown to have minimal effect on testosterone levels or muscle mass gains. However, the main benefit to taking tribulus would seem to be for it’s ability at improving balance in the body and maintaining overall health.
So if you have low testosterone, or a diminished sex drive, tribulus might help normalize the imbalance. Likewise, if your blood sugar or cholesterol levels are out of whack, you may also experience improvement by supplementing with Tribulus terrestris.
So should you supplement with Tribulus terrestris? For maintaining your overall health, I would say a definite yes, but if you’re looking to boost testosterone specifically, there are better options available.