Andarine (S-4)

A scientific study published in 2005 examined the effects of Andarine S-4 on the skeletal muscles, bones, and pituitary glands of castrated male rats. A treatment protocol (3 and 10mg/kg S4- Andarine for 8 weeks) was commenced 12 weeks after castration. Andarine (doses 3 and 10 mg/kg) restored soleus muscle mass and strength and levator ani muscle mass to that seen prior to castration or in intact animals.

In another animal study, the osteoanabolic activities of it were compared with that of dihydrotestosterone (DHT). When S-4 was administered to orchiectomized rats for 4 weeks, their femur bone mineral density and levator ani muscle weight were increased as markedly as DHT. However, prostate weight was not elevated over the normal at any doses tested.

This makes S4 an investigational Selective androgen receptor modulator for possible treatment of conditions related to muscle wasting, osteoporosis, and benign prostatic hypertrophy (BPH). It has the ability to mimic many of the beneficial pharmacologic effects associated with testosterone.