Tribulus Terrestris benefit, side effects, supplement extract, testosterone, research studies
Review of supplement dosage, frequency of use, and combining it with other aphrodisiac herbs that enhances sexuality in men and women
November 16 2019 by Ray Sahelian, M.D.

Benefit and side effects, review, does it work?
Tribulus terrestris, also called "puncture vine," is a plant used around the world. It improves sexual function in humans. What does modern science have to say about this herb? Does it improve athletic performance, does it influence testosterone levels? Does this herb improve sexual performance, erectile function or libido?
   This article reviews the benefits and side effects.

Tribulus Extract 500 mg, 60 pills
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This tropical vine is common in sandy soils throughout India, Pakistan, Sri Lanka and other parts of the world. It can be used by both men and women. It can be combined with other aphrodisiac herbs such as avena sativa, catuaba, ginseng, horny goat weed, maca, muira puama, mucuna pruriens, tongkat ali and yohimbe as long as the dosage of each is a fraction of a capsule.
 

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Suggested use for tribulus products: Use one tablet in the morning on an empty stomach. Take at least 2 or 3 days off each week from use
For a more effective sexual enhancer, try Passion Rx with Yohimbe. Buy Tribulus Terrestris supplement extract, Passion Rx libido booster for men and women, maca herb, tongkat ali, or horny goat weed. You can alternate their use each day.

Latest review of human studies
Effective in women with low sexual desire
DARU Journal of Pharmaceutical Sciences 2014. Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study. This study, done in Tehran, Iran, tested the safety and efficacy of Tribulus terrestris in women with hypoactive sexual desire disorder during their fertile years. Sixty seven women with hypoactive sexual desire disorder were randomly assigned to Tribulus terrestris extract (7.5 mg/day) or placebo for 4 weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured at baseline and after 4 weeks after the end of the treatment by using the Female Sexual Function Index. At the end of the fourth week, patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI, desire, arousal, lubrication, and satisfactionI. Frequency of side effects was similar between the two groups.
   My comments: When I first read the abstract, it did not make sense to me that the dosage was 7.5 mg a day. But then I found the whole article and it said that a syrup was prepared from the ethanolic extract of Tribulus terrestris. There was 3.5 grams of ethanolic extract in every 5 ml of the syrup. The dosage was 7.5 ml of the syrup, not 7.5 mg. Therefore the dosage was roughly 5 to 6 grams of the herb a day.

Gynecol Endocrinol. 2018. Efficacy of Tribulus Terrestris for the treatment of premenopausal women with hypoactive sexual desire disorder: a randomized double-blinded, placebo-controlled trial. We performed a prospective, randomized, double-blind, placebo-controlled trial, with 40 premenopausal women reporting diminished libido, receiving Tribulus terrestris or placebo. Patients treated with the plant aphrodisiac experienced improvement in desire, sexual arousal, lubrication, orgasm, and satisfaction. Women receiving T. terrestris had increased levels of free and bioavailable testosterone. T. terrestris might be a safe alternative for the treatment of premenopausal women with hypoactive sexual desire disorder as it was effective in reducing the symptoms, probably due to an increase in the serum levels of free and bioavailable testosterone.

Not effective in men with erectile dysfunction, dose may have been too low
Actas Urol Esp. 2014. Tribulus terrestris versus placebo in the treatment of erectile dysfunction: A prospective, randomized, double blind study. This study done in Spain selected thirty healthy men ove rthe age of 40 with erectile dysfunction. Patients were randomized into two groups of fifteen subjects each. The study group received 800mg of Tribulus terrestris, divided into two doses per day for thirty days and the control group received placebo administered in the same way. At the dose and interval studied, Tribulus terrestris was not more effective than placebo on improving symptoms of erectile dysfunction or serum total testosterone.
   My comments: The dosage in this study was 800 mg, there is no mention whether it was an extract. The dosage in the trial on women as mentioned above used several grams a day.

Sexual behavior and enhancement
Life Science 2002. Animal studies have found TT to be helpful as a sex booster. Sexual behavior and intracavernous pressure (ICP) were studied in both normal and castrated rats to further understand the role of tribulus as an aphrodisiac. ICP refers to blood flow into the corpus cavernosa of the penis. Adult rats were divided into groups of 8 each that included distilled water treated (normal and castrated), testosterone treated (normal and castrated) and tribulus treated (castrated). Compared to the castrated control, treatment of castrated rats (with either testosterone or tribulus extract) showed increase in prostate weight and ICP. There was also an improvement in sexual behavior as evidenced by an increase in mounting frequency. Aphrodisiac properties of Tribulus Terrestris extract Protodioscin in normal and castrated rats.
   In my personal and professional experience, this herb does seem to have a positive influence on sexual enhancement. I personally have noticed improved sexual performance after a few days of use.

J Pharmacology Pharmacotherapy 2012. Evaluation of the aphrodisiac activity of Tribulus terrestris in sexually sluggish male albino rats. To study the effect of acute and repeated dose administration of lyophilized aqueous extract of the dried fruits of Tribulus terrestris on sexual function in sexually sluggish male albino rats. In order to assess the effect of chronic T. terrestris exposure on the hypothalamus--pituitary--gonadal axis, testosterone level estimation and sperm count were carried out. Twenty-eight-day oral toxicity studies were carried out to evaluate the long-term effects of the TT administration on different body systems. A dose-dependent improvement in sexual behavior was observed with treatment as characterized by an increase in mount frequency, intromission frequency, and penile erection index, as well as a decrease in mount latency, intromission latency, and ejaculatory latency. Chronic administration produced a significant increase in serum testosterone levels with no significant effect on the sperm count. No overt body system dysfunctions were observed in 28-day oral toxicity study. Findings of the present study validate the traditional use of T. terrestris as a sexual enhancer in the management of sexual dysfunction in males.

Testosterone effect, does it increase or decrease?
I have read some websites that claim it increases testosterone levels and I have come across one human trial in women that supports this. Even if it does, I don't know whether it would do so consistently if tribulus is taken for prolonged periods. Animal and human studies have shown conflicting results.

Q. I want you to know that taking tribulus terrestis for two months my total testosterone level went from 162 to 328, my Dr. said keep using it. I have no more menopause hot flashes and sweats. Thank you very much for your product.
   A. We would be interested in more feedback from women who use tribulus to know whether this herb has an influence on menopausal hot flashes or testosterone levels.

Q. Doesn't raising testosterone levels in males, specifically tribulus, increase prostate cancer risk?
   A. Very few studies have been done to determine the long term influence of tribulus terrestris supplement use in terms of testosterone production or release. I do not think it has a meaningful influence on long term testosterone levels. Also, there is no reason to take it daily for months or years.

Journal Ethnopharmacology 2015. Pro-sexual and Androgen Enhancing Effects of Tribulus terrestris: Fact or Fiction. Historically, aphrodisiacs have had a reputation for making sex more achievable and satisfying. It has been long believed that Tribulus terrestris possesses aphrodisiac properties purportedly attributed to its ability to influence levels or mimic function of sex hormones. However, reliable scientific evidence supporting these purported bioactivities are scant and far from conclusive. Analysis of phytochemical and pharmacological studies in humans and animals revealed an important role for TT in treating erectile dysfunction and sexual desire problems; however, empirical evidence to support the hypothesis that this desirable effects are due to androgen enhancing properties of tribulus is, at best, inconclusive, and analysis of empirical evidence from a comprehensive review of available literature proved this hypothesis wrong. While the mechanisms underlying tribulus aphrodisiac activity remain largely unknown, there is emerging compelling evidence from experimental studies in animals for possible endothelium and nitric oxide-dependent mechanisms underlying the aphrodisiac and pro-erectile activities.

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   The potent herbal extracts in this natural aphrodisiac formula include ashwagandha, catuaba bark, cnidium, damiana, horny goat weed, maca, mucuna pruriens, muira puama, tongkat ali, tribulus and yohimbe. A version is available without yohimbe bark extract.

Angina pectoris (chest pain)
Tribulus terrestris has been studied in China and found to reduce the frequency of angina pectoris attacks but I have not yet come across Western studies regarding its role in heart health.

Athletic performance, exercise
Does tribulus terrestris have an influence on testosterone release or enhance testosterone production? One study in rodents indicates that tribulus has an influence on androgen receptors located on brain cells in the hypothalamus. Another animal study found TT use did increase testosterone levels. However, a human study done in Australia in 2007 did not find the herb to have a major influence on muscle mass growth, nor did tribulus seem to influence blood testosterone levels in humans to any great extent. Animal and human studies have shown conflicting results in regards to its influence on testosterone levels. This herb is legal to use in all professional sports. I doubt that it offers any significant athletic performance benefits.

Int J Sport Nutrition Exercise Metabolism. 2000. The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males.
The purpose of this study was to determine the effects of the herbal preparation Tribulus terrestris on body composition and exercise performance in resistance-trained males. Fifteen subjects were randomly assigned to a placebo or tribulus (3.2 mg per kg body weight daily) group. There were no changes in body weight, percentage fat, total body water, dietary intake, or mood states in either group after an 8-week exercise (resistance training) and supplementation period. This study shows supplementation does not enhance body composition or exercise performance in resistance-trained males.

J Strength and Conditioning Research 2007. The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players.
Twenty-two Australian elite male rugby league players were match-paired and randomly assigned in a double-blind manner to either a TT or placebo group. All subjects performed structured heavy resistance training as part of the club's preseason preparations. A tribulus terrestris extract (450 mg each day)) or placebo capsule was consumed once daily for 5 weeks. After 5 weeks of training, strength and fat free mass increased significantly without any difference between the two groups. No between-group differences were noted in the urinary testosterone / epitestosterone ratio.

Phytomedicine 2008. The hormonal effects of Tribulus terrestris and its role in the management of male erectile dysfunction - an evaluation using primates, rabbit and rat.
Tribulus terrestris extract was administered intravenously in primates for acute study. Rabbits and normal rats were treated with orally for 8 weeks. In addition, castrated rats were treated either with testosterone cypionate or tribulus terrestris orally (5mg/kg daily for 8 weeks). Blood samples were analyzed for testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone sulphate levels. In primates, the increases in testosterone, DHT and DHEAS were statistically significant. In rabbits, both testosterone and DHT were increased compared to control, however, only the increases in DHT were statistically significant. In castrated rats increases in testosterone levels by 51% and 25% were observed with testosterone and tribulus terrestris extract respectively that were statistically significant. The herb increases some of the sex hormones, possibly due to the presence of protodioscin in the extract.

J Sport Health Sci. 2017. Tribulus terrestris extracts alleviate muscle damage and promote anaerobic performance of trained male boxers and its mechanisms: Roles of androgen, IGF-1, and IGF binding protein-3.

Weight lifting or training
I have been told that tribulus terrestris is good to use when weightlifting and that the testosterone in it is helpful for building muscle. Is it effective for body building purposes for a man.
   There are no studies to prove this herb is effective for weightlifting or bodybuilding.

I am a 63 yr old male. I am lifting weights to maintain body strength. I was advised to take two Tribulus Terrestris capsules before and two after my work out. I work out every other day. I have high blood pressure controlled by medication. Was the advice I was given correct.
    We don't think this herb is a good option for those considering weight lifting or body building. Creatine and protein supplements are more appropriate.

Blood pressure effect
Antihypertensive and vasodilator effects of methanolic and aqueous extracts of Tribulus terrestris in rats.
J Ethnopharmacol. 2006. Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Safat, Kuwait.
It was concluded that extracts of Tribulus terrestris possess significant antihypertensive activity in spontaneously hypertensive rats. The antihypertensive effects appeared to result from a direct arterial smooth muscle relaxation possibly involving nitric oxide release and membrane hyperpolarization.

Cancer influence

Breast cancer
The inhibitory effect of saponins from Tribulus terrestris on Bcap-37 breast cancer cell line in vitro
Zhong Yao Cai. 2003.
Saponins from tribulus terrestris had potent inhibitory effect on Bcap-37 cell line in a concentration-dependent manner.

Kidney cancer
Experimental study of saponins from Tribulus terrestris on renal carcinoma cell line
Zhongguo Zhong Yao Za Zhi. 2005.
Saponins can significantly inhibit the growth of renal carcinoma cell in vitro, partially, by apoptosis.

Prostate surgery, cancer
I am six years post prostatectomy with a 0.01 PSA level. Is there a risk in taking tribulus? The research seems unclear.
   I am not aware of any research specifically on its role after prostate removal and prostate cancer, but I do not suspect the occasional use will have much of an influence.

Cholesterol and lipids
Effect of saponin from Tribulus terrestris on hyperlipidemia
Zhong Yao Cai. 2003.
The preventive and therapeutic effects of saponin on diet-induced hyperlipidemia in mice have been studied. It showed that in preventive experiment the tribulus terrestris saponin could significantly lower the levels of serum total cholesterol and triglyceride. 

Energy and fatigue fighter
Tribulus has some energy boosting abilities, as do ginseng, cordyceps, maca, and tongkat ali. MultiVit Rx multivitamin formula is a great option for energy enhancement. As with most herbs, I recommend taking breaks from use.

Menopause, perimenopause?
Q. I recently started taking Tribulus to alleviate symptoms of perimenopause (specifically urogenital dryness and inflammation). It does indeed help, and I’m curious how it works. I wanted to try DHEA, but it’s not available over the counter in Canada. Tribulus was recommended as an alternative. I know you generally recommend taking breaks from any herbal supplements discussed on your website. That recommendation notwithstanding, I’m wondering if you think there’s any utility in cycling it with the menstrual cycle – for example, in the same way that some people recommend using wild yam to align or mimic the rhythm of progesterone through a month’s cycle.
   A. I don't have any experience or knowledge using this herb for menopause or perimenopause but my suggestion is to use it as infrequently as possible for long term use, and cycling it is an option.

Mechanism of action, how does it work?
Tribulus terrestris may work by relaxing smooth muscles and increasing blood flow into the corpus cavernosa. The relaxant effect observed is probably due to the increase in the release of nitric oxide from the endothelium and nerve endings. Since the herb relaxes smooth muscles, this may account for its benefits in abdominal colic. The role of  this herb on testosterone production or release needs to be evaluated further before any statements can be made with confidence. Most people notice the benefits on the third or fourth day of use.

Korean J Urol. 2013. Effects and Mechanism of Action of a Tribulus terrestris Extract on Penile Erection. Department of Urology, Gyeongsang National University Hospital, Jinju, Korea. The relaxation effects and mechanism of action of the T. terrestris extract on rabbit corpus cavernosum were investigated in an organ bath. The intracavernous pressure (ICP) was calculated after oral administration of the extract for 1 month to evaluate whether the relaxation response of the CC shown in the organ bath occurred in vivo. Additionally, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in the corpus cavernosum by immunoassay. The T. terrestris extract induced concentration-dependent relaxation of the CC in an organ bath. The mechanism included a reaction involving the nitric oxide/nitric oxide synthase pathway and endothelium of the CC. Moreover, in an in vivo study, the TT extract showed a significant concentration-dependent increase in ICP. Accordingly, the TT extract may improve erectile function.

Historical uses
In Turkey, it is commonly used in folk medicine for blood pressure and cholesterol. In Europe, it has been used in folk medicine throughout history, as far back as the Greeks, for wide-ranging conditions as headache, nervous disorders, and sexual dysfunction. In China and India, this herb has been touted for use in liver, kidney, urinary, and cardiovascular remedies.

What's in the herb and the plant?
The fruits of tribulus contain a number of different substances including saponins (protodioscin, furostanol), glycosides, flavonoids, alkaloids, resins, tannins, sugars, sterols, and essential oil. Recently, two new saponins have been isolated: Terrestrinins A and B, .
   A frequently mentioned substance in tribulus terrestris is protodioscin, which some claim is one of the active substances within this plant. When different samples of tribulus were analyzed, significant differences in the composition of saponins were observed depending on the origin and plant part used. One analysis of products showed considerable variations of 0.17 to 6.5 % in protodioscin content.

Availability of supplements
Tribulus is most often found in combination with other sex-enhancing herbs in various libido products. This herb is also sold by itself often in a dosage ranging from 250 to 750 mg. It is found in a variety of extract potencies. Some examples of tribulus extracts include 20 percent saponins, 40 percent saponins, 45 percent saponins, 60 percent saponins, 20 percent protodioscin, 40 percent protodioscin.

How many different types of tribulus extracts are available?
   The ones I have seen are the following: Tribulus terrestris powder, 10% extract, 20% extract, and 40% extract. There are others but the above are the most commonly used.

Tribulus side effects, caution, safety, risk, danger, adverse reaction
No significant tribulus side effects have yet been reported in the medical literature regarding its use by humans as part of a clinical trial, but there have been case reports of individuals abusing this herb and having certain complications. Rare cases of kidney damage have been reported when misused, overused, or taken together with other herbs or medications that can put stress on the kidneys.
   Little is known about the long-term use of TT consumption in humans. As with most herbs, it is best to take breaks from use in order to minimize potential long term adverse effects. When sheep consume tribulus terrestris as 80% of their diet, liver damage and other changes occur. In my personal experience, and feedback from patients, I have noticed and heard the following tribulus terrestris side effects: more energy, feeling warmer, slightly faster heart beat, restlessness. These adverse event are dose dependent. I personally do not notice the tribulus side effects on dosages less than 300 mg, but these adverse effects are more common above 500 mg.

Tribulus terrestris-induced severe nephrotoxicity in a young healthy male.
Nephrol Dial Transplant. 2010. Clinical Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
We report a case of hepatotoxicity, nephrotoxicity and neurotoxicity in an Iranian male patient who used the plant's extract to prevent kidney stone formation. He presented with seizure and very high serum aminotransferases and creatinine after consuming herbal water for 2 days. Discontinuation of the herbal remedy resulted in improvement in symptoms and normalization of his liver enzymes.

Prostate enlargement, BPH, PSA level
Any reason to be concerned in using it having BPH benign prostate enlargement? Does it influence the prostate gland and PSA levels?
   A. We have not seen any research regarding a connection between tribulus terrestris and prostate enlargement, BPH, and PSA levels. But, as with most supplements, we advise taking breaks from use and this minimizes any potential problems.

Withdrawal
I have not seen any evidence of significant withdrawal symptoms after discontinuation.

Research studies
Cell Physiol Biochem. 2013. Cellular and molecular mechanisms in vascular smooth muscle cells by which total saponin extracted from Tribulus terrestris protects against artherosclerosis.

Hypoglycemic effect of saponin from Tribulus terrestris
Zhong Yao Cai. 2002.
The level of serum glucose, cholesterol and triglyceride was reduced by saponin from Tribulus terrestris. Serum SOD activity of the mice was increased by the saponin.

Sexual behavior and intracavernous pressure (ICP) were studied in both normal and castrated rats to further understand the role of tribulus containing protodioscin as an aphrodisiac. Adult Sprague-Dawley rats were divided into five groups of 8 each that included distilled water treated (normal and castrated), testosterone treated (normal and castrated, 10 mg/kg body weight, subcutaneously, bi-weekly) and tribulus treated (castrated, 5 mg/kg body weight, orally once daily). Decreases in body weight, prostate weight and ICP were observed among the castrated groups of rats compared to the intact group. There was an overall reduction in the sexual behaviour parameters in the castrated groups of rats as reflected by decrease in mount and intromission frequencies (MF and IF) and increase in mount, intromission, ejaculation latencies (ML, IL, EL) as well as post-ejaculatory interval (PEI). Compared to the castrated control, treatment of castrated rats (with either testosterone or tribulus extract) showed increase in prostate weight and ICP that were statistically significant. There was also a mild to moderate improvement of the sexual behaviour parameters as evidenced by increase in MF and IF; decrease in ML, IL and PEI. It is concluded that tribulus extract appears to possess aphrodisiac activity.

Supplement emails
What can you tell me about tribulus terrestris and osteoporosis in men or women by virtue of testosterone increase?
    A. In order to know how whether this plant is effective for osteoporosis, at least a one year study has to be done in women. No such study has been done, therefore it is not possible to say whether TT is an appropriate herb for the treatment of osteoporosis. Other options have been studied much better. Furthermore, even if the plant extract stimulates testosterone release, are the effects consistent over time? Will there be side effects with long term daily use? What is the appropriate dose for adequate testosterone release without other negative consequences? All these questions have not been determined.

Are there hazardous side effects of using Tribulus terrestris and Viagra simultaneously? Can the minimum dose of 25 mg of sildenafil citrate can be taken along? What is the duration of a dosage?
    It is always a good idea, before mixing herbs and pharmaceutical drugs, to first learn how each one work by itself. In the case of tribulus terrestris one can learn the effects by taking in the morning at one capsule a day for at least 4 or 5 days. When combining medications and herbs the dosage of each should be reduced. Each person has a different dosage at which the benefits and side effects will be noticed. Tribulus and other herbs take a few days to start working so there is no point in taking the supplement the same day as a Viagra pill. One can take the herbal pill two or three days in a row before planned sexual activity and then take Viagra, Cialis or Levitra on the day of sexual activity. The effects of tribulus can last a day or two after the last dose.

Ultimate Nutrition Testostro Grow HP - I bought the product to test for myself whether I felt a difference in athletic performance, the increasing libido factor not playing a part as I didn't have any problems in that area. I took the product, 1 tablet (500mg Tribulus Terrestris (aerial, 45% saponins)) for 4 days. The first day taking the product, I immediately noticed an erection lasting until the next morning. The next day, I felt great at the gym. However, on the third day, my sex drive was almost completely gone, and I had nothing to blame but the Tribulus. I didn't use any other supplements or medication at the time. So I stopped taking the Ultimate Nutrition Testostro Grow HP, but the 'normal' sex drive hasn't come back since.
   A. Ingredients in this product are: Amount per serving: Chrysin (100% pure) 800mg Tribulus Terrestris (aerial, 45% saponins) 1500mg Saw Palmetto Extract (fruit) 200mg Nettle Root Extract (0.8% sterols) 155mg Avena Sativa Extract (10:1) 90mg Indole-3-Carbinol (I3C) 40mg Daidzein 30mg Hawthorne Extract (fruit) 130mg Cucurbita Pepo Extract (10:1) 120mg Alpha Lipoic Acid 160mg. With so many different ingredients it is difficult to say what all the interactions are. A good option is to take a break from all supplements for a couple of weeks to allow your body to rebalance itself.

I was told I have slightly lower testosterone than is usual. I have man boobs (probably because in the past I drunk a lot of bourbon; In the present because I drink a lot of soy milk) and at the gym it was suggested I take supplements with Tribulus terrestris. Is that right? Would it help me get rid of my man boobs through exercise and that herb extract?
   A. We doubt this herbal product would be of benefit in reducing man boobs. Exercise is more likely to be of benefit.

More details about the plant
Puncturevine is a prostrate annual herb that grows from a simple taproot. It produces numerous stems, up to several feet long, that are much branched and arise from the crown to produce a dense mat. The fruit is a woody burr with sharp, rigid spines (strong enough to puncture bicycle tires or penetrate shoe soles). Tribulus is Latin for "three-pointed, a caltrop," the shape of which is suggested by the three-pronged fruit, and referring to the caltrop, a military weapon, an iron ball with projecting spikes. It is a serious weed in pastures, roadsides, waste places, vacant lots and cultivated fields. The spines of the tribulus fruit can cause damage to the feet of animals and are a nuisance to children. If growing in orchards or vineyards, it is a problem to the fruit pickers. If grazing animals happen to eat a bur, it may cause injury to the mouth, stomach, and intestines. The foliage is toxic to livestock, especially sheep, when consumed in large quantities.
   This plant is found throughout the United States, except along the northern tier from Montana to New England. It is also found in Asia, South Africa, the Mediterranean region, South America, and Australia. Tribulus terrestris was introduced into the United States with livestock imported from the Mediterranean region. It has become widespread since then. The fruits or berries are the parts most often used in traditional medicine. The composition of different substances within tribulus is likely to vary depending on which part of the world it grows.

History
In China it is used in a number of conditions affecting the liver and kidney as well as the cardiovascular and immune systems. The role of tribulus terrestris in eastern European folk medicine for muscle strength and sexual potency led to two decades of formal (though secret) government-sponsored studies. The development of a formula for tribulus terrestris, along with the rise of a market economy in eastern Europe, has rapidly expanded its use over the last decade. Tribulus terrestris herb is now sold as a standardized pharmaceutical preparation for muscle strength and sexual potency throughout Europe, the Middle East, and Asia.

Forms Available
Tribulus Fruit extract 20% saponins, 40%
Also available are 20% Protodioscin and 40% Protodioscin
Various misspellings include terrestis, tribulous, terrestrus, terristrus, tribulas
 

Other products online:
Physician Formulas Tribulus
Supplement facts and amount per pill: Tribulus Terrestris extract 400 mg each pill (standardized to 40 % saponins)
Now Foods, TestoJack 100, 120 Veggie Caps