Is Tribulus Terrestris Good for You, and Are There any Side Effects?

Tribulus terrestris, commonly known as cow hoof, goat head, or puncture vine, is a plant in the caltrop family. Benefits of tribulus terrestris are that it is antimicrobial and it lowers inflammation and potential side effects include digestive upset and increased risk of blood clots.

Tribulus terrestris is an herbal remedy and supplement. Early research suggests it might improve heart health, lower inflammation, and boost libidos. 

Tribulus terrestris, commonly known as cow hoof, goat head, or puncture vine, is a plant in the caltrop family. It’s native to warm, tropical areas in the Mediterranean, Southern Asia, and Africa. This plant is a small, silky, hairy shrub with a slender, brown root and spiky fruit shaped like hooves. 

Tribulus roots and fruits are old medicines used for thousands of years in China, India, and other parts of Asia. In traditional healing systems, like Ayurveda and traditional Chinese medicine, Tribulus has been used for itchy skin, infertility, low libido, kidney diseases, and heart problems. 

People have used Tribulus as medicine for a long time. While more research is necessary, early animal studies show the herb might have some benefits. 

Antimicrobial

Lab dish and animal studies show that Tribulus extracts impede the growth of some types of bacteria that commonly cause urinary infections, like E. coli. Other studies show that tribulus might help treat a vaginal infection called bacterial vaginosis. 

A small human study compared medication for bacterial vaginosis to treatment with an herbal Tribulus suppository. Both groups had improved symptoms after 1 week, suggesting the suppository worked as well as the medication. The suppository was a mix of herbs, though, so it’s hard to know if the Tribulus was beneficial. 

Lowers inflammation

COX-2 is an enzyme that helps make hormone-like substances called prostaglandins. These prostaglandins can regulate inflammation. One study shows that Tribulus extracts in mice blocked COX-2 activity, suggesting it has anti-inflammatory properties. 

Might lower blood pressure

Tribulus might also lower blood pressure. Experts gave Tribulus extract to mice with high blood pressure and found that it had a relaxing effect on blood vessels at low doses. When blood vessels relax or dilate, a process called vasodilation, blood can flow through better. The study suggested that Tribulus extracts might interact with a chemical called nitric oxide, which causes this relaxing effect. 

Might help sexual dysfunction

There are lots of claims that Tribulus helps with problems getting and keeping an erection, known as erectile dysfunction, but the results of studies are mixed. Some studies show that Tribulus extract helped men with low hormones caused by aging. After 3 months of treatment, testosterone levels rose and erectile dysfunction improved.

Men with erectile dysfunction and a low sexual desire disorder also saw improvement after taking Tribulus. One study found that those who took the extract for 12 weeks had improved orgasms, desire, and overall satisfaction compared to those who didn’t take it. They also had no severe side effects.

However, other studies show Tribulus has no effect on erectile function. In a small group of healthy men with spontaneous erection problems, experts gave some participants a Tribulus extract and some a placebo pill twice daily for 30 days. They measured testosterone and erectile symptoms and found Tribulus wasn’t any more beneficial than the placebo. 

While it’s not clear that Tribulus helps erections, it might help treat sexual problems in women. Female sexual dysfunction is diagnosed when you have ongoing problems with loss of sexual desire, pain during sex, or problems with orgasm. A few small studies found that women who took Tribulus for 4 weeks had a better overall sexual function, including improved arousal and desire and diminished pain.

Might help male fertility

It’s not clear that Tribulus helps boost testosterone levels; the studies show mixed results in animals and in humans. However, an animal study found that Tribulus extract slightly raised sperm production after 28 days. It didn’t have any effect on hormones or treat hormone-sensitive tissues, though. 

Based on this early research, Tribulus might help male fertility by increasing sperm, but more research is needed. 

Might ease pain 

Tribulus Terrestris might also help ease pain. Early animal studies show that high doses of Tribulus extract treated pain in rats. It was less effective than morphine but more so than aspirin. Researchers injected the herb extract directly into the mice, though, so the results may be different from supplements taken orally by humans. 

The majority of studies show that Tribulus is safe with minor side effects. There are a few reports of more serious side effects related to high doses or long-term treatment, though. 

Digestive upset

The most common side effects are digestive symptoms like nausea, vomiting, diarrhea, and stomach cramps. Heartburn and irritation of the lining of your digestive tract are also common.  

Reports of liver and kidney damage

High doses and long-term use of Tribulus might cause liver and kidney damage. There is one report of sudden kidney failure and severe jaundice in a bodybuilder who took Tribulus for an unknown amount of time. A young man also experienced sudden kidney and liver damage after taking high doses of Tribulus extract for kidney stones. 

Might increase the risk of blood clots

There are three case reports of blood clots in patients who took a supplement containing Tribulus while also taking a blood thinner called clopidogrel. It’s hard to know if the herb directly causes these effects, though, or if they’re caused by other ingredients. 

Other drug interactions

Based on animal and lab dish studies, Tribulus terrestris supplements could interact with other medications. In theory, it could interact with blood pressure pills and cause your blood pressure to drop too low. It could also interact with diuretics and antidiabetic medications.

People have used Tribulus for a long time, and it is probably safe for most to consume, but there is very little research on its health benefits for humans. If you’re thinking about taking Tribulus, talk to your doctor and pharmacist first.