STRUCTURE, COMPOSITION & PHARMACOKINETICS
The key compounds found in Tribulus terrestris are extracted from the aerial (above ground) parts of the plant. The subsequent extract contains a whole host of phytoactive and phytodynamic ingredients, the most predominant being protodioscin and its related steroidal saponins. As we now know, protodioscin is the key compound in Tribulus that is most beneficial to the user. However, where it's grown, when it's harvested, and how it is processed, all play a critical role in the potency and efficacy. Unfortunately, most trib-based supplements actually contain only negligible amounts of protodioscin, making the quality of your tribulus supplement a real issue if you're looking for true benefits. Researchers have credited protodioscin's physiological effects as being the main source of Tribulus' T-boosting power because of its remarkable ability to enhance testosterone precursors such as dehydroepiandrosterone1 and dehydroepiandrosterone sulphate.2 As a result, and simply stated, protodioscin-rich Tribulus extracts have been shown to directly elevate the "master" of all muscle-building hormones, testosterone, and its precursor, luteinizing hormone.3
MECHANISM OF ACTION : How does Tribulus terrestris work?
Various mechanisms have been suggested regarding the exact cause for the beneficial effects of Tribulus. Experimental studies dating back to the late 1970's propose three possible mechanisms, which fit today's understanding of performance and body composition manipulation. These mechanisms include, first and foremost, testosterone elevation, also Nitric Oxide (NO) release and diuretic effects (water retention control). So let's take a closer look at how Tribulus terrestris stimulates these powerful biochemical effects in our bodies to enhance performance and physique transformation.
Several hormones stimulate the body's own production of testosterone. The two most important and potent stimulators of testosterone secretion are again luteinizing hormone (LH), which is secreted from the pituitary gland and also gonadotrophic releasing hormone (GnRH) from the hypothalamus. This regulatory system controlling testosterone is often referred to as the hypothalamic-pituitary-testicular axis. It operates under a classic negative feedback control. When testosterone levels are low, LH and GnRH stimulate testosterone production. When testosterone is high, LH and GnRH can be inhibited, subsequently shutting down the body's natural production of testosterone. In a groundbreaking study by Milanov et al. (1981), eight healthy male subjects aged 28 to 45 years were administered 250 mg of Tribulus terrestris, three times daily at 8-hour intervals for 5 days. Hormonal levels were determined before and after the intake of the protodioscin including luteinizing hormone (LH). As you can see in Figure.1, LH levels are markedly elevated following supplementation. Further work by Koumanov et al., also showed similar elevations in LH levels following Tribulus extract supplementation.
But what about its effects on testosterone, the hormone that signals new muscle growth, fat loss and strength gains?
In the same study, authors show that Tribulus supplementation in humans increases plasma testosterone by an impressive 40% (See Figure.2). As many studies have shown, elevation of testosterone by only a few percentage points is highly correlated with increased muscle strength and decreased fat mass. The interesting thing is that these elevations were achieved with an early generation of low-potency tribulus terrestris yielding only minimal levels of protodioscin. On-going research is currently underway to determine the impact high levels of protodioscin have on testosterone elevation. Researchers speculate that the net increase may be many times that of what was observed in those early studies. This belief is further supported by the truly impressive feedback from athletes who have used the new generation of protodioscin-rich tribulus products. (For an excellent review on this area see Herbst and Bhasin 2004).4
NITRIC OXIDE (NO) STIMULATION
In addition to being a potential modulator of blood flow, Nitric Oxide (NO) can significantly impact muscle contractility and nutrient metabolism. In particular, recent human data indicates that NO plays a role in muscle glucose uptake5 and is vital for sustained performance and recovery from exercise. In essence, these studies point to the massive impact NO metabolism can make on your muscle function and your nutrient delivery potential. So what is the link between Tribulus and NO synthesis? Well, there are at least two solid studies suggesting Tribulus stimulates the release of nitric oxide. The first study is indirect in that it measures behavior rather than physiological response, and suggests Tribulus increases NO release from nerve endings which stimulate the Corpus Cavernosum (tissue responsible for erection) and increases blood flow.7 The second study directly measures nitrergic neurotransmission.6 Further data has revealed that in healthy patients, 250 mg per day of Tribulus for three months increased sexual desire in 67% and erectile function in 62% of the participants.7 What was even more interesting is that in some patients these effects were experienced in 10 days or less!
QUALITY & SAFETY
With all herbals, there are issues of quality, selection and storage. Where was the plant harvested? What time of year was the plant taken? How was it stored and packaged? How were the active ingredients extracted?
To date, every positive study has used a Bulgarian source of Tribulus terrestris (specifically from the southern region), and it seems there is something in the plant harvested from this part of the country that provides particularly high concentrations of protodioscin. Bulgarian trib is half the battle to attaining true body-changing potency. The other half involves the processing, which will be further addressed shortly. One thing's for certain--the quality and effectiveness of Tribulus products is always dependent on its protodioscin content, and to a somewhat lesser degree, its total saponins content. To ensure consistent potency, the manufacturer should be using HPLC (High performance liquid chromatography) to calculate the content of protodioscin, furastanol saponin and total saponins in each batch of Tribulus. Below is just one example showing identification of protodioscin using HPLC. The large peak at 24 minutes in the protodioscin content of the Tribulus sample should be much larger than all other peaks as it is the most important active ingredient. (See Figure 3)
One important issue prior to the use of any compound is its safety profile, and in fact, Tribulus is one of the safest on the market. Researchers Tanev and Zarkov were the first to examine the toxicological and safety aspect of Tribulus extract and protodioscin administration. They concluded that the Tribulus extracts could be included in the group of practically nontoxic substances. Human data in a series of studies has also shown no negative consequences to the use of Tribulus extracts over a range of dosing protocols.8,9,10 In addition, toxicological studies,11 teratogenic studies12 as well as clinical check ups3,13,14 show that Tribulus extracts have a very good tolerance and no undesired mental or physiological side effects. Now that studies and real-world results have shown Tribulus is safe as well as effective, how should you be using it? Well, first of all, as with all supplements, be sure to follow the label instructions for suggested use before ingesting. And then beyond that, the general recommendation is as follows: because protodioscin is rapidly released into the body after ingestion, you should take it immediately pre-workout to get the greatest release of testosterone. If you can afford to double dose, late afternoon/early evening might also be advantageous as this is the time when testosterone levels are at their lowest. Another reason to take Tribulus close to exercise is that blood flow is greater at this time, which should consequently generate greater effects on androgen release.
ANDROTEST--THE INDUSTRY'S PROTODIOSCIN CONTENT LEADER
As noted earlier, the origin of the Tribulus and the extraction procedures used are the essential factors to ensuring maximum potency and optimum results. And the fact is, only one product on the market puts it all together to provide maximum effectiveness. AndroTest uses Bulgarian Tribulus extract that is standardized to contain an unprecedented 40-48% protodioscin, 60% furastanol saponins, and 80% total saponins. ProSource puts this southern Bulgarian trib through a "multiple extraction" process (sometimes up to 20 extractions) to yield what lab tests have shown to be the absolute most potent Tribulus on the market. Most companies put the raw tribulus through maybe one or two extractions that yield much less protodioscin content. Although these inferior products will be cheaper, that is because they will be far less potent and significantly less effective. As one of our Research & Development staffers said:
A POWERFUL ANABOLIC SYNERGY
The AndroTest formula was designed to promote maximum testosterone elevations via a synergistic approach that combines two of the most potent natural T-boosters known to science. The other key active ingredient in this potent stack is "Tongkat Ali" (Eurycoma longifolia Jack), standardized for quassinoid content (including eurycomalacton, eurycommanon, and eurycomanol). In fact, it is the same proprietary extract, called LJ-100-- that is used in impressive human studies done at a major university15 and recently presented at a prominent medical conference16. One study found that after 3 weeks of LJ-100 use, DHEA levels increased 47%, SHBG (sex hormone binding globulin) decreased 66%, and the Free Testosterone Index escalated 73%. In the Quality of Life questionnaire (to LJ-100 users) 91% of the subjects reported improvement in the sexual component, 73% reported improvement in the physical component, and 82% noted improvement in the psychological component. In just a short time, the Tongkat ali extract not only helped improve androgen levels, but helped contribute to a greater sense of well being. Another study found subjects who performed an intense training regimen over 5 weeks and supplemented with Tongkat ali increased their strength by over 40 percent, while increasing fat-free mass, and reducing body fat17.
From the industry's leading researchers to world champion bodybuilders to weekend warriors, all of us recognize the vital correlation between testosterone enhancement and significant lean mass gains. You simply can't have one without the other. The evidence speaks for itself. This new generation of protodioscin-rich tribulus represents what may be the single most potent and powerful natural T-booster ever introduced to our industry. In fact, based on all the scientific data and our own personal testing, we are convinced that, when combined with proper training and diet, this amazing compound may very well be the first REAL alternative to synthetic anabolics the sport of bodybuilding has seen to date.
1. Adimoelja,A., and Adaikan, P.G. (1997) Protodioscin from herbal plant Tribulus terrestris L improves male sexual function possibly via DHEA. Int.J.Impot.Res 9 (1).
2. Adaikan, P.G., Gauthaman, K., Prasad, R.N.V., Ng, S.C. (2001) History of herbal medicines with an insight on the pharmacological properties of Tribulus terrestris. Aging Male 4: 163 - 169.
3. Koumanov, F., Bozadzhieva, E., Andreeva, M.(1982) Clinical trial of the drug "Tribestan". Savr.Med 4: 211-215..
4. Herbst KL, Bhasin S. (2004) Testosterone action on skeletal muscle. Curr.Opin.Clin Nutr.Metab.Care 7(3):271-7.
5. Scherrer, U., Randin, D., Vollenweider, P., Vollenweider, L., Nicod, P. (1994) Nitric oxide release accounts for insulin's vascular effects in humans. J.Clin.Invest 94(6):2511-5
6. Gauthaman, K., Ganesan, A.P., Prasad, R.N. (2003) Sexual effects of puncturevine (Tribulus terrestris) extract (protodioscin): an evaluation using a rat model. J.Alt. Comp. Med 9: 257-265.
7. Gauthaman, K., Adaikan, P.G., Prasad, R.N.,Goh, V.H.N., Ng, S.C. (2000) Changes in hormonal parameters secondary to intravenous administration of Tribulus terrestris extract in primates (abstr.6). Int.J.Impot.Res 12 (2): s11.
8. Antonio, J., Uelmen, J., Rodriguez, R., Earnest, C., 2000. The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males. Int.J.Sport.Ex.Metab 10: 208-215.
9. Moeloek, N., Pangkahila, W., Tanojo, T.D. Adimoelja, A. (1994) Trials on Tribulus terrestris on idiopathic ologo-astheno-teratozoosperms. Programme and Abstract book. 6th National Congress Indonesia Society of Andrology and 3rd International Symposium Andrology, Manado, Indonesia.
10. Wang B., Ma, L., Liu, T (1990) 406 cases of angina pectoris in coronary heart disease treated with saponin of Tribulus terrestris . Chung. Hua. Chieh. Ho .Ho .His. Tsa. Chih 10:85-7.
11. Tanev, G., Zarkova, S. (1985) Toxicological studies on Tribestan. Cited in Zarkova S. Tribestan: Experimental and Clinical Investigations. Chemical Pharmaceutical Research Institute, Sofia.
12. Ilieva, Z. (1981) Embriotoxic and teratological studies on Tribestan. Chemical Pharmaceutical Research Institute, Sofia.
13. Protich, M., Tsvetkov, D., Nalbanski, B. (1983) Clinical trial of the preparation Tribestan in infertile men. Akush.Ginekol 22(4):326-329.
14. Viktorov, I.V., Kaloyanov, A.L., Lilov, L. (1982) Clinical investigation on Tribestan in males with disorders in the sexual function. Med.Biol.Inf.
15. M.I.M Tambi, S. Othman, and J.M. Saad "Water-soluble extract of LJ100TM as a potential natural energizer for healthy aging men" Department of Biochemistry, Department of Medicine, University of Malaya, Malaysia.
16. Abstracts of the 8th International Congress of Andrology, 12-16 June 2005, Seoul, Korea. Int J Androl. 2005 Jun;28 Suppl 1:1-133.
17. Hamzah, S., Yusof, A. (2003) The ergogenic effects of eurycoma longifolia jack: A pilot study: (Astr 007): Joint conference BASEM and BASES. Br.J.Sports.Med 37:464-470