Because steroids are lipophilic, they diffuse easily through the cell membranes, and therefore have a very large distribution volume. In their target tissues, steroids are concentrated by an uptake mechanism which relies on their binding to intracellular proteins (or " receptors ", see below). High concentration of steroids are also found in adipose tissue, although this is not a target for hormone action. In the human male, adipose tissue contains aromatase activity, and seems to be the main source of androgen-derived estrogens found in the circulation. But most of the peripheral metabolism occurs in the liver and to some extent in the kidneys, which are the major sites of hormone inactivation and elimination, or catabolism (see below).
RAD 140 : Testolone studies are still being produced, but it has been known to have equal potency and effectiveness to that of LGD4033. Dosages ranged between 20mg to 30 mg per 24-36 hours for maximum skeletal muscle hypertrophy. Safe durations for research have been tolerated for up to 12 weeks, however, developing trials may indicate tolerance for up to 24 weeks. It is important to note that RAD140 systematically regulates the neuroexcitatory amino acid Kainate which activates glutamate receptors in the brain. Kainate acid’s role in neuronal cell death (specifically in the hippocampus) has been shown to be a primary contributor to Alzheimer’s disease. RAD140 has demonstrated positive results in the prevention of Kainate acid production and medical based research published by The Endocrine Society suggests RAD140 can improve brain health through neuroprotective properties in as little as 13 days (Jayaraman, 2014). This characteristic of nonsteroidal SARMs is not added in the General Benefits section of this article because it is exclusive only to RAD140.