Thread: Trenbolone: a potent anabolic with reduced estrogenic/androgenic potential

Trenbolone: a potent anabolic with reduced estrogenic/androgenic potential
by Anthony Roberts

With summer less than 8 weeks away, steroid users are looking towards anabolics like trenbolone, which has a reputation for building muscle without any fat gain or water retention. A 2010 study gave insight into some of the mechanisms of action behind tren, confirming what most of us have known for years:



Steroids. 2010 Jun;75(6):377-89. Epub 2010 Feb 4.
Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activity.

Yarrow JF, McCoy SC, Borst SE.

Geriatric Research, Education & Clinical Center, VA Medical Center, Gainesville, FL 32608, United States. jfyarrow@ufl.edu

Abstract

Recently, the development of selective androgen receptor modulators (SARMs) has been suggested as a means of combating the deleterious catabolic effects of hypogonadism, especially in skeletal muscle and bone, without inducing the undesirable androgenic effects (e.g., prostate enlargement and polycythemia) associated with testosterone administration. 17beta-Hydroxyestra-4,9,11-trien-3-one (trenbolone; 17beta-TBOH), a synthetic analog of testosterone, may be capable of inducing SARM-like effects as it binds to androgen receptors (ARs) with approximately three times the affinity of testosterone and has been shown to augment skeletal muscle mass and bone growth and reduce adiposity in a variety of mammalian species. In addition to its direct actions through ARs, 17beta-TBOH may also exert anabolic effects by altering the action of endogenous growth factors or inhibiting the action of glucocorticoids. Compared to testosterone, 17beta-TBOH appears to induce less growth in androgen-sensitive organs which highly express the 5alpha reductase enzyme (e.g., prostate tissue and accessory sex organs). The reduced androgenic effects result from the fact that 17beta-TBOH is metabolized to less potent androgens in vivo; while testosterone undergoes tissue-specific biotransformation to more potent steroids, dihydrotestosterone and 17beta-estradiol, via the 5alpha-reductase and aromatase enzymes, respectively. Thus the metabolism of 17beta-TBOH provides a basis for future research evaluating its safety and efficacy as a means of combating muscle and bone wasting conditions, obesity, and/or androgen insensitivity syndromes in humans, similar to that of other SARMs which are currently in development.

source

Originally Posted by heavyiron

Parabolan (Trenbolone) was manufactured for human consumption many decades ago by Negma, also called Haxabolan. There have been both human and animal studies.

Right, but all of these studies refer to humans in them and are all very recent. Just seemed strange is all.