# Tribulus Terrestris Update



## 3752 (Jan 7, 2005)

*Richard B. Kreider, PhD, FACSM*
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I recently came across a web site promoting the ergogenic value Tribulus terrestris. The site claimed that

Tribulus supplementation would naturally boost testosterone levels leading to greater gains in muscle

mass and strength during training. Is this true? This article discusses what we know and don't know

about Tribulus terrestris so you can make an informed decision of whether to add this supplement to your training table.
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*Background*
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Tribulus terrestris is a plant (also known as puncture weed/vine or caltrops) that is mainly grown in sandy

soil environments. It produces a fruit that is protected by a spiny burr. The extract from the fruit has

been used in herbal medicine as a diuretic, for colic pains, and to fight hypertension and

hypercholesterolemia (1,2). It has also been shown to increase testosterone levels (3) and improve sexual

function in animals (3-5) as well as to reduce symptoms of angina pectoris in heart patients (6).

Excessive intake of Tribulus terrestris has been reported to cause neuromuscular disorders in sheep (7-8).

The active agent in Tribulus is believed to be protodioscin. Protodioscin is a precursor to

dehydroepiandrosterone (DHEA). As you may know, DHEA and androstenedione are precursors to

testosterone. As one ages, androgen levels decline. Therefore, DHEA and androstenedione

supplementation have been theorized as a means of naturally increasing testoserone levels particularly in

older individuals. Although Tribulus is a precursor to DHEA, Tribulus is believed to indirectly affect

testosterone levels by stimulating the release of leutinizing hormone (LH). LH serves to stimulate the

natural production of testosterone. Theoretically, moderately increasing testosterone availability during

training may promote greater gains in strength and muscle mass.
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*Does Tribulus Terrestris Work?*
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Well, as you know, the theoretical rationale behind many supplements sounds promising. However, the

promises often fade when one looks at the scientific evidence supporting the theories. Tribulus is no exception. To date, there are only a handful of studies that have investigated the effects of Tribulus

terrestris supplementation on hormone regulation, sexual function, health, and/or training adaptations.

Most of these studies have been conducted in animals. Although several web sites claim that Tribulus

terrestris supplementation markedly increases LH and testosterone levels, I was only able to find two

published studies that have investigated the effects of Tribulus terrestris supplementation on training

adaptations in humans.

In the first study, Antonio and colleagues (9) evaluated the effects of Tribulus terrestris supplementation

during training on body composition and performance. In a double blind and randomized manner, 15

resistance-trained males ingested either 3.21 mg/kg/day of a placebo (P) or Tribulus terrestris (T) for eight

weeks during a standardized resistance-training program. Prior to and following supplementation,

subjects completed dietary inventories, a mood state psychological inventory, and had body composition

(skinfolds and hydrostatic weighing) and total body water (bioelectrical impedance) measurements

determined. The subjects also performed a maximum repetition tests on the bench press and leg press at

100% and 200% of body weight, respectively. Results revealed that Tribulus terrestris supplementation

had no significant effects on changes in mood states, total body weight (P +0.6, T +0.9 kg), total body

water (P +0.9, T +0.3 liters), hydrostatically determined percent body fat (P +0.2, T +0.0 %), or gains in

bench press (P +28.4, T +3.1 %) or leg press (P +26.1, T +28.6 %) muscle endurance. Although LH and

testosterone levels were not assessed in this study, results indicated that Tribulus terrestris

supplementation (approximately 250 mg/day) during resistance training had no significant effects on body

composition or training adaptations.

Proponents of Tribulus terrestris supplementation have suggested that the dosage in the previous study

may have been insufficient, that Tribulus terrestris may be more effective when coingested with other

anabolic precursors, and/or that Tribulus terrestris may have a greater impact on untrained subjects

initiating training. However, research findings from a study by Brown and associates (10) do not support

these contentions. In the first part of this study, 10 subjects were evaluated to determine the effects of

ingesting a placebo or anabolic precursors on hormone levels. Subjects had fasting blood determined and

then ingested a placebo or a supplement containing 100 mg androstenedione, 50 mg DHEA, 250 mg

Tribulus terrestris, 195 mg Chrysin, 100 mg Indole-3-carbinol, and 180 mg Saw palmetto. Blood samples

were obtained every hour for six hours. Results revealed that anabolic precursor supplementation

significantly increased androstenedione levels. However, no significant differences were between the

placebo and anabolic precursor trials in LH, follicle stimulating hormone (FSH), estradiol, free

testosterone, or total testosterone levels. These findings suggest that although anabolic precursors may

increase androstenedione levels, they have no significant acute effect on other androgenic or estrogenic

hormones.

In the second phase of this study, 20 untrained young male subjects participated in a 3-day per week

resistance training program for 8-weeks. In a double blind and randomized manner, subjects ingested a

placebo (P) or a supplement containing 300 mg androstenedione, 150 mg DHEA, 750 mg Tribulus

terrestris, 625 mg Chrysin, 300 mg Indole-3-carbinol, and 540 mg Saw palmetto (Andro-6) every day

during weeks 1, 2, 4, 5, 7, and 8 of training. Fasting blood samples were obtained prior to

supplementation and after 2, 5, and 8 weeks of supplementation. Body composition (via skinfolds and

hydrostatic weighing) and one-repetition maximum (1RM) upper and lower body strength tests were

determined at 0, 4, and 8 weeks of supplementation. In addition, muscle biopsies were obtained prior to

and following the supplementation/training interventions to assess changes in muscle fiber diameter.

Results revealed that chronic Andro-6 supplementation during training increased fasting androstenedione,

estradiol, and estrone levels while decreasing high-density lipoproteins (HDL) levels. No significant

differences were observed in LH, FSH, total testosterone, free testosterone, or estriol levels. Moreover,

no significant differences were observed between groups in changes in body composition, muscle fiber

diameter, or gains in 1RM strength. These findings suggest that ingesting Tribulus terrestris (750

mg/day) with other anabolic precursors does not significantly affect body composition or training adaptations.
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*Bottom Line*
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Despite popular claims, there currently appears to be little if any data supporting the ergogenic value of

Tribulus terrestris supplementation for resistance-trained athletes. Additionally, *studies that have **evaluated the ergogenic value of other anabolic precursors in younger athletes have shown little to no*

*benefit with some potentially dangerous side effects.* My advice is to stay away from these types of anabolic precursors unless recommended by your physician.
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*References:*
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1. Bucci LR. Selected herbals and human exercise performance. *Am J Clin Nutr. *72:624S-36S, 2000.

2. Arcasoy HB, Erenmemisoglu A, Tekol Y, Kurucu S, Kartal M. Effect of Tribulus terrestris L. saponin mixture on some

smooth muscle preparations: a preliminary study. *Boll Chim Farm*. 137:473-5, 1998.

3. Dimitrov M, Georgiev P, Vitanov S. Use of tribestan on rams with sexual disorders. *Vet Med Nauki*. 24:102-110, 1987.

4. Adaikan PG, Gauthaman K, Prasad RN, Ng SC. Proerectile pharmacological effects of Tribulus terrestris extract on the

rabbit corpus cavernosum. *Ann Acad Med Singapore*. 29(1):22-6, 2000.

5. Adimoelja A. Phytochemicals and the breakthrough of traditional herbs in the management of sexual dysfunctions. *Int J*

*
Androl. *23(Suppl 2):82-4, 2000.

6. Wang B, Ma L, Liu T. 406 cases of angina pectoris in coronary heart disease treated with saponin of Tribulus terrestris.
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*Zhong Xi Yi Jie He Za Zhi. *10:85-7, 1990.

7. Bourke CA, Stevens GR, Carrigan MJ. Locomotor effects in sheep of alkaloids identified in Australian Tribulus terrestris.
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*Aust Vet J*. 69:163-165, 1992.

8. Bourke CA. Staggers in sheep associated with the ingestion of Tribulus terrestris. Aust Vet J. 61:360-363, 1984.

9. Antonio J, Uelmen J, Rodriguez R, Earnest C. The effects of Tribulus terrestris on body composition and exercise

performance in resistance-trained males. *Int J Sport Nutr Exerc Metab *10:208-15, 2000.

10. Brown GA, Vukovich MD, Reifenrath TA, Uhl NL, Parsons KA, Sharp RL, King DS. Effects of anabolic precursors on

serum testosterone concentrations and adaptations to resistance training in young men. *Int J Sport Nutr Exerc Metab*.

10:340-59, 2000.
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## Nine Pack (Oct 30, 2006)

Excellent post Paul. I have used trib on a few occassions, and I know it's sometimes recommended for pct, but as there has been a lack of scientific evidence to support it's efficacy, it's just been a 'suck it & see' approach. This is not something I would do with a drug, but an over the counter supplement seemed harmless enough, as worse the case scenario was that I was a few quid down & nothing to show.

I think you're right though, especially when it comes to someone who has used exogenous testosterone as the suppression of natural levels is so significant that even if this stuff did exert some effect, it would be like spitting in a barrel at best. I'll be trying Hack's suggestions for pct this time as I am concerned about crashing hard post cycle, as I will be off for quite some time till my next cycle.


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## fits (Feb 3, 2004)

Very nice article. I have tried trib before and and after a few weeks of taking it i definately noticed some effects, mostly being horny and getting 'excited' at random times i never normally would. tried again recently and i didn't nitice anything......... I like to go by othere peoples experiances rather than just believe articles or some on ethe so called studies, after all some times you read a study that says a particular supp works wonders only to find out that the company that made the supp, financed the study! just as drug companies may finance studies that discredit supps!

some times a suck it and see for yourself appraoch is best :beer1:


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## 3752 (Jan 7, 2005)

i have tried it numerouse times the last being last year when i was off the steroids trying to get the wife pregnant i used 750mg of Trib ed for 2 months and it did nothing ....


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## fits (Feb 3, 2004)

Pscarb said:


> i have tried it numerouse times the last being last year when i was off the steroids trying to get the wife pregnant i used 750mg of Trib ed for 2 months and it did nothing ....


 just out of interest what brand did you use? i cant remember what dose i used i think it was 3 X that though, nd it kicked in after a couple of weeks. as i said second time....nothing. I know chefx recons theres only a few good products about with the active ingredient in them (or enough of it)

Maybe it only works in high doses and for people with lower natural test levels? i know there have been times where i have felt that my levels were low....but then times when its definately not! maybe i fluctuate alot, can any one go and get tested at their GP if they are willing to pay?

I dont think ill pay for trib again unless i hear people talking up a brand with details of their own experiance!


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## DB (Oct 31, 2003)

i was taking 3000mg ED and i reckon i noticed positive effects in PCT

that was bulk powders caps


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## 3752 (Jan 7, 2005)

well the studies say it doesnt work and last year when i was on it (reflex) i had my bloods done before and after my test levels where 3.3 before and after now that is low test.....

i have yet to speak to anyone who has not had to use a stupid amount to see anything and yet to see a posative study on the effectiveness of Trib...


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## SD (Sep 3, 2004)

Nice find Paul,

I tried Tribestan Trib alongside some Ecdysterone, the combination worked in as much as it made me feel stronger but the aggression that came with it was not worth it. Oddly I don't get that aggressive on Test?

I got the Tribestan because Chef said it was the only one that worked, had to import it though.

SD


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## fits (Feb 3, 2004)

i remember them from the supps list. I ordered all of the sups but a lot never did turn up, i did'nt end up paying for them though!


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