Andarine is an orally active partial agonist for androgen receptors. It is less potent in both anabolic and androgenic effects than other SARMs. In an animal model of benign prostatic hypertrophy, andarine was shown to reduce prostate weight with similar efficacy to finasteride, but without producing any reduction in muscle mass or anti-androgenic side effects.
This suggests that it is able to competitively block binding of dihydrotestosterone to its receptor targets in the prostate gland, but its partial agonist effects at androgen receptors prevent the side effects associated with the anti-androgenic drugs traditionally used for treatment of BPH.

What are the functions of Andarine S4?

1. For Cutting. Andarine's properties are very alike with steroids Anavar and Winstrol, the only difference is that S4 can better provide lean muscle gains. In fact, there have been many cases of bodybuilders gaining up to 3 pounds of lean muscle while on a caloric deficit! S4 displays the same binding resemblance to AR, hence presenting similar fat burning effects. S4 can also minimize LPL (lipoprotein lipase) - an enzyme that causes lipid accumulation and plays a role in storing adipose tissue (excess body fat). The AR oxidizes this adipose tissue and uses it as its preferred energy source, allowing the body to decrease excess fat at an amazing rate.
2. For Bulking. S-4 isn't the sarm that comes to mind when we think "BULKING", but it's properties in muscle gain shouldn't be overlooked. During the holiday season, many people take advantage of the excess food and snacks available and jump on some well known bulking SARMs such as LGD 4033 or RAD 140. While there isn't an enormous 15 lb leap in muscle like these "bulk specific" products, S-4 can provide relatively large muscle gains and utilize these excess calories to provide an extra 8-10 lbs in muscle while also keeping the body relatively lean. This steady increase in muscle mass can limit the amount of work one needs to do for a leaner summer body.

How does Andarine S4 work?
SARMS themselves bind to the AR (androgen receptor) and demonstrate osteo (bone) and myo (muscular anabolic activity. When something binds and activates the AR, it alters the expression of genes and increases protein synthesis, which in turn builds muscle. SARMS cause muscle growth in the same method as steroids, the difference being that SARMS do not enhance the growth of ones prostate and other sexual organs. SARMS do not cause the many problems that anabolics can cause. SARMS do not have toxicity, in some circumstances only cause minimal suppression, allowing for a rapid recovery, as opposed to steroids that can cause long term problems from the high rates of suppression and provide a sense of well being each day that many steroids cannot cause.