Posted by Another Jeff on March 26, 1997 at 12:03:56:
I know the earlier part of our previous discussion is waaaaay down the page at the
bottom just above the posting form so lets continue here. Rather than go into the
hypothalamus/testicular axis and the reasons why I think tribestan increases spermatogenesis
(increased GnRH results in increased LH, ABP, and testosterone?), I would very much
like an honest critique about this article found on the net. In particular if you are
familiar with the studies mentioned and the sponsors of those studies (Sopharm?).
Thanks man- I value your opinion. Here is the article excerpt:
...Early studies using animals clearly demonstrated Tribestan's effects on some
key reproductive functions. Among the findings in rats treated for 7-20 days
with moderate-to-high oral doses were marked increases in spermatogenesis
(sperm production) and improvements in the quality, motility and survival time
of sperm. Studies on boars administered Tribestan at 70 mg per kilogram of
bodyweight per day for 10 days demonstrated a dramatic recovery of libido
and improved sexual reflex time, even in those animals with established
prolonged impotence.
The research of greatest interest to bodybuilders and other athletes are clinical
studies conducted at the Chemical Pharmaceutical Institute. Tests on healthy
men ages 28-45 demonstrated that three tablets (250 mg each) taken for just
five days increased testosterone levels by a significant 30% or more (Milanov,
Maleeva and Taskov, Sopharma documentation, 1981). That would help
explain the popularity of the product with world-class Bulgarian athletes,
especially before competition.
The mechanism by which Tribestan produces this effect is believed to be
through stimulation of the secretion of leutinizing hormone (LH, a
gonad-stimulating hormone produced by the pituitary gland). The only catch in
the study was that in some cases, an increase in the level of estradiol occurred
as well. While it could enhance growth-hormone secretion and overall mass
increases, this could bode poorly for those who are highly susceptible to
gynecomastia (male development of female-type breast tissue) or insulin
resistance. In women, follicle-stimulating hormone, but not LH, and estradiol,
but not testosterone, were increased. This differential effect allows Tribestan
to be effectively used by both sexes to stimulate reproductive function.
Additional studies sponsored by the Chemical Pharmaceutical Institute were
carried out on 212 males, ages 14-60, at three sites: the Higher Military
Medical Institute, and the institutes of Endocrinology, Gerontology and
Geriatrics, and Obstetrics and Gynecology at the Bulgarian Medical
Academy. All individuals studied had reproductive disorders of some type,
ranging from impotence to hypogonadism to infertility. Tribestan was
administered in doses generally ranging from 750-1,500 mg per day for an
average of 30-60 days.
The results confirmed the previous work in that testosterone levels increased
in many cases, as did libido, frequency and strength of erections and the
sexual reflexes (recovery from sexual activity). Other positive changes
observed in a number of cases were a reduction of cholesterol and positive
psychological effects such as improved mood and increased self-confidence.
No adverse effects were noted in any of the clinical studies, and additional
research using animals demonstrated no adverse effects on the central nervous
or cardiovascular systems. Administration of Tribestan had a mild diuretic
effect in several cases in the human trials.
Toxicity was found to be extremely low both in acute studies (the oral dose
required to kill 50% of rats tested, the LD subscript 50, is more than 10
grams per kilogram of bodyweight) and over extended periods (23 months at
oral doses of up to 150 mg per kilogram of bodyweight per day). No known
negative effects presently exist when Tribestan is used as a nutritional
supplement or when used as adjunctive therapy (under a physician's guidance)
in the absence of other prescribed medications.
Right now, fewer than a handful of products in the U.S. contain any
preparation of the Tribulus plant, but that's likely to change soon. Although
m&f writer Mauro Di Pasquale, MD, rates Tribestan as questionable in his
Bodybuilding Supplement Review based on the lack of significant scientific
substantiation of any anabolic effects in athletes, I'm willing to go out on a limb
on this one and suggest that it appears to have real potential for bodybuilders.
Time will tell.
SPECIFIC PHARMACOLOGICAL ACTIVITIES OF TRIBULUS
MALES - Increases libido (sexual desire); improves strength of
erection and spermatogenesis (formation and development of sperm);
may increase the level of testosterone (a hormone secreted by the
testes, the most potent natural anabolic-androgenic hormone).
FEMALES - Increases libido; improves ovulation effect; decreases the
vasomotor symptoms accompanying menopause; reduces apathy and
aggressiveness.
Before joining muscle & fitness, Jim Wright, PhD, served as chief of the
Exercise Science Branch, U.S. Army Fitness School. He also directed
research in exercise physiology at the U.S. Army Research Institute of
Environmental Medicine and has participated in many investigations of
muscle physiology and performance. The author of more than 60
professional publications, Wright consults for several federal and state
agencies and athletic organizations, and serves as technical reviewer for
professional journals. In the early '70s, he was a National Collegiate
Powerlifting Champion.
The above is an excerpt of an article. It mentions studies that prove elevated
testosterone from oral tribestan doses. Please comment- THANKS.
AJ