OTC testerone boosters

Young Gun

A Scientific Analysis of Over-the-Counter Testosterone Boosters
by Jay McCombs

Introduction

Question One: What do you get when you mix 19 molecules of carbon, 28 molecules of hydrogen, and 2 molecules of oxygen? It could be a lot of things, but maybe (if you are lucky) it could order into 17beta-Hydroxyandrost-4-en-3-one. Sound familiar? That's right, it's your friend and mine testosterone.

Question Two: How can you increase your body's natural production of testosterone? That's a tougher one. Pro-hormones are no longer easily obtained legally and personal stashes will soon dwindle, making this question even timelier.

In the next few pages I will review the scientific literature through exhaustive searches of Medline, CINAHL, EBM, and SPORTDiscus with regard to some of the most popular Over-the-Counter testosterone boosters currently on the market. I will examine the possible mechanism of action for each and assess whether any of these alleged testosterone boosters have a positive effect on testosterone production, exercise performance, or both.


Tribulus Terrestris

The first on the list is of course Tribulus Terrestris, specifically the steroidal saponin protodioscin. Tribulus has long been used in various cultures as an aphrodisiac and treatment for sexual dysfunction. The theory then follows that this increase in libido is probably due to increased levels of androgens, which would also mean that Tribulus generates some type of ergogenic effect. So what does the research say?

First lets look at several studies conducted on animals that examined the aphrodisiac properties of Tribulus. The first study investigated the response of corpus cavernosal tissue isolated from rabbits that were fed Tribulus for eight weeks [1]. After harvesting, tissues were then exposed to protodiscin, contractile agents, and relaxant agents. Tissue strips from treated rabbits showed an increased rate of relaxation when administered various relaxing agents after said tissue was constricted with norepinephrine. This indicated that Tribulus seemed to have some effect on the rabbits’ ability to get erections; however, no specific mechanism could be pinpointed.

Follow up research ensued. The next two studies, conducted on castrated rats, examined variables that essentially investigated how sexually aroused the rats were [2, 3]. The researchers found that Tribulus supplementation definitely appeared to increase the rats libido. Again however, an exact mechanism could not be found.

The latest study by the same researchers tried to determine the mechanism of action by which the mice and rats each appeared to experience heightened arousal levels [4]. Once again, rats were fed Tribulus for 8 weeks. Immunoreactivity studies were performed on the androgen receptor (AR), while Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) levels were taken from the rat paraventricular nucleus in order to determine activity.

The researchers found activity at both receptors increased over control; however, this muddied the waters a bit. NADPH-d neurons are the same that contain NOS. Previous research indicated these neurons were inhibited by increased androgen activity. The researchers attributed this to effects mediated through the conversion of androgens to estrogen, which would then increase the number of NADPH-d neurons. The end result was the same: Tribulus undoubtedly heightened arousal, but whether this was a result of increased androgen levels was unclear.

So, rats having sex is fun to watch, but we want to get buff, right? Well, lets talk about primates. Primates given Tribulus intravenously showed a transient (read, 30 minutes) increase in testosterone and DHT and a longer increase in DHEAS (an increase of about 25-50% for about 120 minutes), which might be helpful with DHEA mediated effects on sexual function if your testosterone was low [5]. Otherwise, this effect probably would not be noticeable.

In my opinion, the nail in Tribs coffin comes from the following two studies. The first study examined body weight, body composition, maximal strength, dietary intake, and mood states of subjects before and after 8 weeks of taking either a Tribulus extract or a placebo [6]. No significant change was found in any of these parameters after supplementation with Tribulus when compared with the placebo group.

The next study evaluated claims that LH and subsequently testosterone levels were increased above normal after ingesting Tribulus extracts [7]. Baseline levels of testosterone and its metabolites in urine and serum were established for all subjects. Participants were then fed a heaping gram of Tribulus daily for 4 weeks. Testosterone levels were checked routinely, and researchers found no significant increase in hormone levels beyond normal day to day variations. This research is the most significant and relevant to our discussion here today. It was conducted on humans and looked for the two variables we are most concerned with: increasing testosterone and, in turn, increasing exercise performance—and in both of these studies Tribulus failed to do either.

I just briefly want to discuss the Sopharma research. This research was not included in this review for several reasons. It has not been published in a reputable English language journal and subsequently peer reviewed; and, subsequent research has been unable to elicit the same results when conducted in a similar manner [7].

In my opinion Tribulus is not useful for increasing androgen levels in healthy males or improving exercise performance. There may be some effect on individuals with androgen deficiencies where Tribulus acts as a precursor to deficient DHEA, but at this time the only conclusion that can be definitively drawn about Tribulus is that it seems to be quite effective at making castrated rats horny [8].


ZMA

Next we'll take a look at ZMA, a combination of Zinc Monomethionine Aspartate (30mg), Magnesium Aspartate (450 mg) and Vitamin B-6 (10.5 mg). The theory behind ZMA is simple: zinc and magnesium are important in the production of steroids and B-6 is important in energy production, two things crucial to athletes. If you become deficient in any of the ingredients in ZMA you see a subsequent decrease in androgen production and performance in general--and there is evidence that a number of diets may be deficient in all three [9-22]. In addition, high protein intake and exercise can increase daily B-6 requirements. Lastly, intake of other minerals can affect the absorption of magnesium and zinc, making supplementation attractive [23-27].


But what evidence is there to show that ZMA intake increases exercise performance or testosterone levels? In vitro research clearly illustrates how supplementation with magnesium can decrease the amount of testosterone bound to human serum albumin, thus, increasing free testosterone [28]. Another study, this time actually conducted on people, showed an increase in performance in untrained males after 7 weeks of supplementing with magnesium [29].

Another interesting effect of both zinc and magnesium is their influence on cortisol secretion. Fourteen-day supplementation with magnesium decreased cortisol secretion in male subjects during ergometer testing. A study conducted with oral dosages of zinc ranging from 25 mg to 50 mg showed an inhibitory affect on cortisol secretion over 240 minutes [30, 31]. This evidence suggests that ZMA supplementation could cause performance increases and an increase in testosterone via the decrease of the catabolic hormone cortisol.

In conclusion, ZMA supplements definitely have the potential to increase testosterone production and performance in individuals deficient in any of the constituent ingredients. The likelihood of raising testosterone production above physiological maximums seems unlikely given the nature of the effect of the product; therefore, supplementation with ZMA should be looked at as a preventative measure to make sure testosterone levels don’t fall below peak.

Androstenetrione


Now let's look at a totally different approach to increasing testosterone production. Androstenetrione, marketed by Ergopharm under the name 6-oxo, is a proven aromatase inhibitor (AI) (aromatase is the enzyme responsible for the conversion of androgens to estrogen) and has been used extensively as a legal, over-the-counter source for post-steroid-cycle therapy in order to help restore the reduced testosterone production that results from exogenous androgen use [32-36].



Recently, an interest in androstenetrione as a standalone means to increasing testosterone has peaked. The theory is simple: decrease the amount of estrogen reaching the brain (a potent stimulus to decrease the hormones that cause androgens to be made) and see the body try and correct the drop by an increase in the production of androgen and estrogen precursors. Since you are taking a substance that is reducing the body's ability to make estrogen from said compounds, the only other option is an increase in testosterone to maintain the same amount of estrogen.

While there is a paucity of clinical research on the effects of androstenetrione on testosterone levels (actually only one study regarding the sexual differentiation of castrated rats) there is ample research on the effects of other aromatase inhibitors and their effect on hormone production [37]. Several recent studies showed that hypogonadal elderly men showed an increase in testosterone while using an AI [38, 39]. Perhaps the most relevant and exciting research in the area shows an acute decrease in estradiol. This research also shows an increase in LH and subsequent increases in testosterone in both young and old men supplementing with an AI [40]. Theoretically, androstenetrione should largely work in the same way.

Conclusion

For those of you that just like to skip to the end, I'll give you a quick summary of my findings regarding Tribulus, ZMA and androstenetrione. There is no published literature that indicates any benefit to supplementing with Tribulus in regards to increasing testosterone or exercise performance. ZMA shows promise as a preventative supplement, much like a multivitamin, with the goal of maintaining testosterone production at its peek. Androstenetrione shows the most promise of increasing levels of testosterone production above physiological norms by modulating the signals that tell your body to make more hormones.

Young Gun

Just to further piss all over the I love tribulus people

J Ethnopharmacol. 2005 Jun 30; [Epub ahead of print] Related Articles, Links


The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men.

Neychev VK, Mitev VI.

Department of Chemistry and Biochemistry, Medical University, 2 Zdrave str., Sofia-1431, Bulgaria.

OBJECTIVE:: The aim of the current study is to investigate the influence of Tribulus terrestris extract on androgen metabolism in young males. DESIGN AND METHODS:: Twenty-one healthy young 20-36 years old men with body weight ranging from 60 to 125kg were randomly separated into three groups-two experimental (each n=7) and a control (placebo) one (n=7). The experimental groups were named TT1 and TT2 and the subjects were assigned to consume 20 and 10mg/kg body weight per day of Tribulus terrestris extract, respectively, separated into three daily intakes for 4 weeks. Testosterone, androstenedione and luteinizing hormone levels in the serum were measured 24h before supplementation (clear probe), and at 24, 72, 240, 408 and 576h from the beginning of the supplementation. RESULTS:: There was no significant difference between Tribulus terrestris supplemented groups and controls in the serum testosterone (TT1 (mean+/-S.D.: 15.75+/-1.75nmol/l); TT2 (mean+/-S.D.: 16.32+/-1.57nmol/l); controls (mean+/-S.D.: 17.74+/-1.09nmol/l) (p>0.05)), androstenedione (TT1 (mean+/-S.D.: 1.927+/-0.126ng/ml); TT2 (mean+/-S.D.: 2.026+/-0.256ng/ml); controls (mean+/-S.D.: 1.952+/-0.236ng/ml) (p>0.05)) or luteinizing hormone (TT1 (mean+/-S.D.: 4.662+/-0.274U/l); TT2 (mean+/-S.D.: 4.103+/-0.869U/l); controls (mean+/-S.D.: 4.170+/-0.406U/l) (p>0.05)) levels. All results were within the normal range. The findings in the current study anticipate that Tribulus terrestris steroid saponins possess neither direct nor indirect androgen-increasing properties. The study will be extended in the clarifying the probable mode of action of Tribulus terrestris steroid saponins.

Tribulus Terrestris Update
Richard B. Kreider, PhD, FACSM

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 dont know
about Tribulus terrestris so you can make an informed decision of whether to add this supplement to your
training table.

Background
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.

Does Tribulus Terrestris Work?
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.

Bottom Line
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.

The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males.

Antonio J, Uelmen J, Rodriguez R, Earnest C.

Human Performance Laboratory, University of Nebraska, Kearney, NE 68849-3101, USA.

The purpose of this study was to determine the effects of the herbal preparation Tribulus terrestris (tribulus) on body composition and exercise performance in resistance-trained males. Fifteen subjects were randomly assigned to a placebo or tribulus (3.21 mg per kg body weight daily) group. Body weight, body composition, maximal strength, dietary intake, and mood states were determined before and after an 8-week exercise (periodized resistance training) and supplementation period. There were no changes in body weight, percentage fat, total body water, dietary intake, or mood states in either group. Muscle endurance (determined by the maximal number of repetitions at 100-200% of body weight) increased for the bench and leg press exercises in the placebo group (p <.05; bench press +/-28.4%, leg press +/-28.6%), while the tribulus group experienced an increase in leg press strength only (bench press +/-3.1%, not significant; leg press +/-28.6%, p <.05). Supplementation with tribulus does not enhance body composition or exercise performance in resistance-trained males.

Young Gun

Taken from Iron Arena

Young Gun

What's the scoop on ZMA? Does it work?
ZMA is a popular new supplement that claims to increase anabolic hormones and strength in athletes. What is the evidence for these claims of improving athletic performance and overall fitness?

How does ZMA work? (No, but we'll get to that later)
ZMA is a combination of two essential dietary minerals (zinc and maganesium) and vitamin B6. Zinc and magnesium are sometimes not adequately supplied in the diet, while vitamin B6 generally is. The zinc is in the chemical forms zinc methionine and aspartate; the magnesium is in the aspartate form.
There is no scientific evidence for any claim that ZMA has any effects beyond those of taking equivalent amounts of zinc, magnesium and vitamin B6 in any other form.
All of these substances are healthy and thus the combination will also be healthy so long as it is not overdosed.

Are there any side effects?
Possible side effects can arise from taking too much (overdosage).

Zinc: More than 50 mg daily often increases the need for dietary copper; more than 100 mg daily might cause toxic symptoms.

Magnesium: More than 1000 mg daily might cause diarrhea.

Vitamin B6: More than 200 mg per day may lead to peripheral neuropathy (nerve pain in the extremities).

What else do I need to know about ZMA?
A study claiming that ZMA increases anabolic hormones and strength in athletes was conducted by L. R. Brilla, Western Washington University, Bellingham, WA, and V. Conte, BALCO Laboratories, Burlingame, CA.
While their results show statistically significant differences between the ZMA and placebo groups following 8 weeks of intensive training (higher testosterone levels and greater increases in strength) -- the study was significantly flawed.

The beginning levels of zinc and magnesium in these athletes' blood were already low. (Average serum zinc was 0.82 mcg/ml; deficiency threshold is 0.7 mcg/ml. Average serum magnesium was 19.6 mcg/dl; deficiency threshold is 16 mcg/dl.)
Increased exercise raises the body's need for zinc in a variety of ways. The fact that levels of zinc and magnesium dropped in the control groups' blood (to 0.8 mcg/ml of zinc and 18.0 mcg/dl of magnesium) shows that the increased exercise had this expected effect.

So both groups needed more of these essential minerals, probably even before the intensive training, but only one group got it.
What happened here can be understood if one thinks about the normal diet eaten by "members of the University football team" (the study's subjects). Their diet is probably low in zinc, magnesium and B6, if not actually deficient -- which is probably true for most unsupplemented people in the US. High protein intake (undoubtedly consumed by these football players) increases the need for B6, and zinc is particularly important for protein (muscle) synthesis.