AUTHORITY NUTRITION

Does Tribulus Terrestris Really Work? An Evidence-Based Look

Written by Grant Tinsley, PhD on October 5, 2017

Many of today's popular dietary supplements come from plants that have been used medicinally since ancient times.

One of these botanicals is Tribulus terrestris, which is purported to have a variety of health benefits, including reduced blood sugar and cholesterol, altered hormone levels and increased sexual function and libido.

This article tells you everything you need to know about this plant, its health effects and whether you should consider consuming it as a dietary supplement.

Tribulus Terrestris

Tribulus terrestris is a small leafy plant. It’s also known as puncture vine, Gokshura, caltrop and goat’s head (1).

It grows in many places, including parts of Europe, Asia, Africa and the Middle East (2).

Both the root and fruit of the plant have been used medicinally in Traditional Chinese Medicine and Indian Ayurveda medicine (3).

Traditionally, people have used this plant for a variety of potential effects, including to enhance libido, keep the urinary tract healthy and reduce swelling (3).

Today, Tribulus terrestris is widely used as a general health supplement, as well as in supplements that claim to increase testosterone levels (4).

Summary: Tribulus terrestris is a plant that has been used for a variety of potential health benefits for many years. It is popular as a general health supplement and as an ingredient in testosterone booster supplements.

Although people often take Tribulus terrestris for its potential effects on sexual function and testosterone, it has also been studied for other important effects.

One study examined the effects of taking 1,000 mg of Tribulus terrestris per day in 98 women with type 2 diabetes.

After three months, women taking the supplement experienced lower blood sugar and cholesterol levels, compared to those who took a placebo (5).

Animal studies have also shown that Tribulus terrestris may reduce blood sugar levels, help protect against blood vessel damage and help prevent increases in blood cholesterol (6, 7).

While these findings appear promising, more research is needed before this plant can be recommended for these health benefits.

Summary: Preliminary evidence shows that Tribulus terrestris may improve blood sugar control and cholesterol in people with diabetes. However, research in humans is limited.

A quick online search for Tribulus terrestris supplements shows that many products made with the plant are focused on boosting testosterone.

One review analyzed the results from 12 major studies on the plant’s effects in men and women aged 14–60. The studies lasted from 2–90 days, and the participants included healthy people and those experiencing sexual problems.

The researchers found that this supplement did not increase testosterone (4).

Other researchers found that Tribulus terrestris may increase testosterone in some animal studies, but that this result is not usually seen in humans (8).

Summary: Despite marketing claims, Tribulus terrestris does not appear to increase testosterone in humans. This conclusion is based on studies in men and women of various health statuses and ages.

Even though this supplement may not increase testosterone, it may boost libido.

Some researchers found that when men with reduced sex drives consumed 750–1,500 mg of Tribulus terrestris daily for two months, their sexual desire increased by 79% (4, 9).

Also, 67% of women with very low libidos experienced increased sexual desire after they took supplements of 500–1,500 mg for 90 days (4).

Other studies have also reported that supplements containing the herb enhanced sexual desire, arousal and satisfaction in women with low libido (10).

However, studies in men with erectile dysfunction have yielded mixed results.

Some research shows that taking 800 mg of this supplement per day may not effectively treat erectile dysfunction (11).

However, other reports showed significant improvements in erections and sexual satisfaction with a dose of 1,500 mg per day (12).

While it seems that Tribulus terrestris may improve libido in women and men, more research is needed to clarify the extent of the sexual effects of this supplement.

Summary: Research has found that Tribulus terrestris may improve libido in women and men with reduced sex drives. Studies on the herb as a treatment for erectile dysfunction have shown mixed results, with higher doses appearing to be more beneficial.

Active individuals frequently take Tribulus terrestris supplements to improve their body composition by increasing muscle or decreasing fat (13).

This may be partly due to the herb’s reputation as a testosterone enhancer, though research shows it may not actually live up to these claims.

In fact, research is also very limited on whether the plant improves body composition or performance in active individuals and athletes.

One study examined how Tribulus terrestris supplements affected the performance of elite male rugby players.

The men took the supplements during five weeks of weight training. However, by the end of the study, there were no differences in improvements in strength or body composition between the supplement and placebo groups (14).

Another study found that eight weeks of taking this supplement with an exercise program did not improve body composition, strength or muscle endurance more than a placebo (15).

Unfortunately, no research is available on the effects of Tribulus terrestris in exercising women. However, it’s likely that these supplements would also be ineffective in this population.

Summary: Tribulus terrestris does not seem to increase muscle, decrease fat or improve exercise performance more than a placebo.

In addition to the potential health effects discussed already, Tribulus terrestris may have several other effects in the body:

  • Fluid balance: This plant may act as a diuretic and increase urine production (16).
  • Immune system: Immune system activity in rats has been shown to increase when they are given this supplement (17).
  • The brain: As part of a multi-ingredient supplement, Tribulus terrestris may have antidepressant effects in mice (18).
  • Inflammation: A test-tube study showed possible anti-inflammatory effects (19).
  • Pain relief: High doses of this supplement may provide pain relief in rats (20).
  • Cancer: Test-tube research has shown a possible anti-cancer effect of Tribulus terrestris (21).

However, almost all of these effects have only been studied in animals or test tubes, and even then, the evidence is very limited (3).

Much more research, both in animals and humans, is needed to find out whether Tribulus terrestris has these effects.

Summary: Although many people speculate about the health effects of Tribulus terrestris, there is very limited support for many of these claims. Much of the existing research has been conducted in animals or test tubes, not humans.

Researchers have used a wide variety of doses to assess the effects of Tribulus terrestris.

Studies investigating its potential blood sugar-lowering effect used 1,000 mg per day, while research examining libido enhancement used doses from 250–1,500 mg per day (4, 5).

Other studies prescribed dosages relative to body weight. For example, several studies have used doses of 4.5–9 mg per pound (10–20 mg per kg) of body weight.

So, if you weighed about 155 pounds (70 kg), you might take a dose of 700–1,400 mg per day (4).

Saponins in Tribulus Terrestris

Saponins are chemical compounds in Tribulus terrestris, and they are thought to be responsible for its health benefits.

Many supplements list the dose along with the percentage of saponins, which refers to the amount of the supplement that is made up of these compounds.

It is common for Tribulus terrestris supplements to contain 45–60% saponins. Importantly, a higher percentage of saponins means that a lower dose should be used, as the supplement is more concentrated.

Minimal Side Effects

Several studies using a variety of dosages have reported minimal side effects and no safety concerns (12, 22).

Uncommon side effects include minor stomach cramps or reflux (10, 12, 22).

However, a study in rats raised the concern of potential kidney damage. Also, one case of toxicity associated with Tribulus terrestris was reported in a man who took it to prevent kidney stones (23, 24).

Overall, the majority of studies do not show that this supplement has harmful side effects. However, it is important to consider all the potential risks and benefits.

If you want to use Tribulus terrestris, make sure you discuss the appropriate dose with your healthcare provider.

Summary: Most studies have reported that Tribulus terrestris does not cause major side effects. However, stomach cramps are an occasional side effect, and limited evidence has shown a potential risk of toxicity.

Tribulus terrestris is a small leafy plant that has been used in traditional Chinese and Indian medicine for many years.

While it has a long list of potential health benefits, many have only been studied in animals.

In humans, there is some evidence that it may improve blood sugar control and cholesterol levels in people with type 2 diabetes.

And although it doesn’t increase testosterone, Tribulus terrestris may improve libido in men and women.

However, it won’t improve body composition or exercise performance.

While most research shows that this supplement is safe and causes only minor side effects, there have been isolated reports of toxicity.

As with all supplements, you should consider the potential benefits and risks before taking Tribulus terrestris.

An evidence-based nutrition article from our experts at Authority Nutrition.

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