Andarine (developmental code names GTx-007, S-4) is a

selective androgen receptor modulator Selective androgen receptor modulators (SARMs) are a class of drugs that tissue selectivity, selectively activate the androgen receptor in specific tissue (biology), tissues, promoting muscle and bone growth while having less effect on male re ...

(SARM) which was developed by GTX, Inc for the treatment of conditions such as muscle wasting,

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in Bone fracture, fracture risk. It is the most common reason f ...

, and

benign prostatic hyperplasia Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, urinary retention, inability t ...

(BPH), using the

nonsteroidal antiandrogen A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens lik ...

bicalutamide Bicalutamide, sold under the brand name Casodex among others, is an antiandrogen medication that is primarily used to treat prostate cancer. It is typically used together with a gonadotropin-releasing hormone (GnRH) analogue or surgical remo ...

as a lead compound. Development of andarine for all indications has been discontinued, in favor of the structurally related and improved compound

enobosarm Enobosarm, also formerly known as ostarine and by the developmental code names GTx-024, MK-2866, and S-22, is a selective androgen receptor modulator (SARM) which is under development for the treatment of hormone sensitive cancer, androgen rece ...

(ostarine; GTx-024; S-22). Andarine is an orally active

partial agonist In pharmacology, partial agonists are drugs that bind to and activate a given Receptor (biochemistry), receptor, but have only partial Intrinsic activity, efficacy at the receptor relative to a full agonist. They may also be considered Ligand (bio ...

of the

androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

(AR). In intact male rats, 0.5 mg andarine daily was shown to reduce prostate weight to 79.4%, and non-significantly increased

levator ani The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis. It is attached to the inner surface of each side of the ...

muscle weight. In castrated male rats, this dose restored only 32.5% prostate weight, but 101% levator ani muscle weight This suggests that andarine is able to competitively block binding of

dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone primarily involved in the growth and repair of the prostate and the penis, as well as the production o ...

to its receptor targets in the prostate gland, but its partial agonist actions at the androgen receptor prevent the side effects associated with the antiandrogens traditionally used for treatment of BPH. Andarine was first described in the literature by 2002. It completed phase 1

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

s for

cachexia Cachexia () is a syndrome that happens when people have certain illnesses, causing muscle loss that cannot be fully reversed with improved nutrition. It is most common in diseases like cancer, Heart failure, congestive heart failure, chronic o ...

in 2003. Three phase 1 trials (1a, 1b, 1c) were completed with the drug involving 86 healthy male and female volunteers. Phase 2 trials were planned for 2004. However, development of andarine was discontinued, reportedly due to findings of visual disturbances in clinical studies. Andarine is thought to have been the first SARM to enter human clinical trials.

References

{{Androgen receptor modulators Abandoned drugs Carboxamides Phenol ethers Selective androgen receptor modulators Trifluoromethyl compounds

See also

References