LGD-3303 like LG121071, was developed by Ligand Pharmaceuticals. The chemical structure of LGD-3303 resembles that of LGD-4033, another SARM developed by Ligand Pharmaceuticals.

LGD-3303 is a drug which acts as a selective androgen receptor modulator (SARM), with good oral bioavailability. It is a selective agonist for the androgen receptor, producing functional selectivity with effective dissociation of anabolic and androgenic effects, acting as a partial agonist for androgenic effects, but a full agonist for anabolic effects.[1] It has been investigated as a possible treatment for osteoporosis, and was shown in animal studies to enhance the effectiveness of a bisphosphonate drug.

RAD 150, also known as TLB 150, is the esterified version of the popular SARM, RAD 140. RAD 140 has been studied most thoroughly on male gonadectomized rats suffering from neurodegenerative decline due to decreased androgen levels. Overall, the fascinating study conducted by Jayaramen et. Al came to the conclusion that in male rats, supplementation with RAD 140 had neuroprotective effects on the brain via MAPK signaling. Additionally, the study found that treatment with RAD 140 was actually just as effective in protecting against cell death as testosterone treatment Study.. In addition to providing neuroprotection, testing of RAD 140 in juvenile monkeys over a 28 day period was shown to have led to an average of 10% increase in body weight. Through the use of DEXA scans it was found that the weight gain was primarily lean muscle mass.

Esterification occurs when a substitution reaction takes place. The specific substitution reaction that occurs when a compound becomes an ester, is derived from a carboxylic acid. The hydroxyl group (-OH) of the carboxylic acid is replaced with an alkyl (-O-) group. Esterification occurs when the carboxylic acid is exposed to heat and a strong acid, normally sulphuric acid. In some cases, various other strong acids such as hydrochloric acid will be used in order to catalyze the substitution reaction Study..

RAD 150 is the esterified version of RAD 140. The main structural difference between the two compounds is the group of benzoate esters that were added during the substitution reaction of esterification. Adding the group of benzoate esters increases the alkalinity of the compound thus making it more stable than RAD 140 itself Study.. In order to synthesize RAD 150 from Testolone, it has to undergo the process of esterification. During the substitution reaction, a group of benzoate esters is added to Testolone in order to turn the compound into its esterified version, accounting for the main structural difference between the two compounds. By adding the benzoate ester group, the compound now has increased alkalinity, thus indicating that the esterified compound is more stable than Testolone Study. Additionally, in a similar fashion to other esterified SARMs, the bioavailability and the half-life of RAD 150 are increased. With increased bioavailability, the compound is absorbed much faster, and with increased half-life the compound is active for far longer than RAD 140, the nonesterified compound. This indicates that by esterifying RAD 140 there are additional potential benefits that are added. Furthermore, when comparing Testolone to RAD 150, RAD 150 is similar to other esterified SARMs with an increase in half-life and bioavailability. By increasing the half-life of RAD 150, the compound is considered active for a longer period of time than when supplementation with Testolone. Additionally, when bioavailability is increased, the compound is absorbed at a faster rate. It can be concluded that when Testolone undergoes esterification, there are several additional benefits that can be derived from the resulting compound, RAD 150.

YK-11 (also known as myostine) is a selective android receptor modulator that has been clinically proven to partially activate the android receptor, as well as act as a myostatin inhibitor.

Researchers Lee et. Al published a fascinating research study featuring YK-11 as a muscle-building/ muscle sparing compound in the condition of sepsis.

By giving groups of mice two different doses of YK-11 for ten days through their food (oral administration, 350mg/kg and 700 mg/kg), they found that there were significant differences in how these groups reacted to a peritoneal injection of e.coli.

Researchers noted that YK-11 inhibited the action of the myostatin, a hormone that stops muscle growth in mammals Study. .

Not only did mice receiving the YK-11 retain their body mass through the disease process, but they also were noted to have a favorable fat to muscle ratio, meaning less fat and more lean tissue than their non-dosed counterparts.

Researchers also discovered that treated mice were able to recover muscle mass lost in the back and thighs, after being exposed to the systemic E. coli. Muscle cells also resisted atrophy when compared to the control group.

In addition to the impact on the muscles of these mice, there were implications for the immune response to gram-negative bacteria as well. YK-11 decreased the negative side effects of bacterial disease in the body including a decrease in the endotoxin excreted by the bacteria, and a decrease in the lungs of inflammatory cytokines.

Biomarkers indicating organ damage were also significantly decreased, including markers in the liver and kidneys (AST, ALT, and BUN). Usage of YK11 also improved the clearance of the deadly bacteria from the mice’s organs. Study.

It is also interesting to note that researchers also examined the survivability rate from sepsis, and mice treated with YK-11 were more likely to survive to the 72-hour mark than those not treated with YK-11, and treated mice had little to no evidence of bacterial colonization in their major organs.

S23 is an orally available selective androgen receptor modulator or SARM. Originally developed by GTX as a form of hormonal male contraception in rats,it exhibits a high affinity for the androgen receptor with a Ki of 1.7 nM. Researchers, Jones et. Al published a research study comparing the effectiveness of S-23 in both castrated and intact male rats.

In castrated male rats, the effective dose of S23 in the prostate was 0.43 mg/d and 0.079 mg/d in the levator ani muscle. In intact male rats, doses greater than 0.1 mg/d of S-23 suppressed levels of luteinizing hormone (LH) by more than 50%. Furthermore, this dose of S-23 corresponded with decreased size of the prostate and increased size of the levator ani muscle Study. In intact males treated with S-23 as well as estradiol benzoate (to maintain sexual behavior), after 10 weeks there was no sperm found in the testis in four out of the six subjects and no reported pregnancies in all six of the subjects. After the treatment, infertility was completely reversed and 100% of the mating trials resulted in pregnancy.

The effects of S23 on muscle mass and body fat are comparable to the effects of anabolic steroids. In a study conducted in male rats it was discovered that while being treated with S23, the overall body weight and fat mass of the rats decreased. As it was previously mentioned, rats being treated with S23 were also given estradiol benzoate (EB) to maintain sexual behavior. EB is considered an estrogen which is known to cause muscle loss, however, when combined with S23 the effects of the estrogen were canceled out and the muscle mass of the male rats increased Study. . Additionally, in another study using rats, the effectiveness of S23 was tested against muscle loss due to long-term usage of glucocorticoids. This study also looked into the effects of S23 on castration-induced atrophy. In both cases, there was muscle loss but by supplementing S23 and testosterone to the rats the dexamethasone-induced dephosphorylation of Akt is blocked. Overall this study indicated that using S23 may be a more effective way of treating glucocorticoid-induced muscle loss Study.

LYN-X

Super concentrated formula

LYN-X formulation

possible side effects

Super concentrated formula

LGD3303

RAD150

YK11

S23

possible side effects