RAD140, also known as testolone, is a new investigational drug which has become popular among bodybuilders, who claim that it has muscle-building effects. RAD140 belongs to a class of compounds called selective androgen receptor modulators, or SARMs
SARMs bind to androgen receptors that are found in different areas of the body. Normally, these receptors interact with androgens, which are a group of steroid hormones. Androgens like testosterone, dihydrotestosterone, and androstenedione are naturally produced by the body
SARMs and testosterone tend to have similar effects because they work on the same receptor. The intended targets of SARMs include the muscles, bones, and liver
SARMs are of particular interest to researchers because they are selective about where they work. They mostly target muscle and bone tissues, and appear to have minimal effects on the prostate and other organs. Because of this, some researchers believe that SARMs could potentially treat hormone-related or muscle-wasting disorders with fewer side effects than existing treatments.
This potential has also made SARMs a popular choice over testosterone or steroids for bodybuilders. Although testosterone and steroids boost muscle growth, they also have unwanted effects on the prostate and reproductive organs, among others.
Mechanism of Action
RAD140 works by selectively stimulating androgen receptors in the body. It targets receptors in the muscle and bone and has had little to no observed effect on the reproductive organs.
This compound stimulates muscle growth by promoting the development of muscle cells and proteins.
The selective ability of SARMs is not fully understood yet. According to some researchers, they may target and selectively activate different proteins than testosterone. This results in only certain androgen receptors – mainly in the muscles – being activated.
The chemical structure of RAD140 is very different from the structure of steroid hormones like testosterone. Thus, the pathways that convert testosterone into other hormones (like estrogen) cannot act on testolone. This means that it is impossible to get estrogen related side effects from RA140.
Based on a study in rats, some researchers have suggested that RAD140 could activate receptors in injured regions of the brain. In the brains of rats given RAD140, MAPK activity increased, thus protecting neurons from damage. RAD140 activates androgen receptors in muscles, but not in most other tissues. Some researchers believe that this reduces testolone’s potential to produce side effects (compared to testosterone or other steroids), but more research is needed.
RAD140 (Testolone) vs. Ostarine
Ostarine, also known as Enobosarm, is a popular SARM that has undergone limited testing in humans. One clinical trial has investigated ostarine’s ability to prevent the drastic weight loss (cachexia) caused by severe illnesses.
RAD140 and ostarine are both SARMs; some researchers have found minimal effects on the prostate and reproductive organs, but without high-quality clinical studies, we can’t know if this is truly the case.
Anecdotally, testolone and ostarine differ when it comes to their effects on muscle and fat. According to anecdotal reports from people who use SARMs, ostarine has milder muscle-building effects and is better for fat loss. It’s the usual choice for “cutting cycles” and for those that want to gain modest but lean muscle mass. On the other hand, many of these same anecdotes report that RAD140 is a stronger SARM that provides better muscle growth. It’s a more popular choice for bulking.
Remember that none of these anecdotes have ever been tested in clinical research, and they should all be taken with several large grains of salt. People’s reports of their own experience can be interesting, but they cannot replace high-quality, placebo-controlled studies conducted by experts in the field.
Bodybuilding resources usually recommend a dosage of 10 to 30 mg per day for men and 5 to 10 mg per day for women.
Users typically cycle RAD140 for 8 to 12 weeks. The off-cycle can vary: some recommend they last as long as the cycles, while others think that a shorter off-cycle of 6-8 weeks is sufficient. Some users have stayed on as much as 30mg of RAD140 for three years straight with no negative effects on sex drive or health.
Veterans will tailor these depending on their labs, checking to see how the cycles affected their liver markers and hormone balance.
