Product name: Andarine
Synonym: S-4, GTx-007;S4
CAS No.: 401900-40-1
Packing: 1kg/foil bag
Appearance: White crystalline powder
Andarine (GTx-007, S-4) is an investigational selective androgen receptor modulator (SARM) developed by GTX, Inc for treatment of conditions such as muscle wasting, osteoporosis and benign prostatic hypertrophy,using the non-steroidal androgen antagonist bicalutamide as a lead compound.
What is S-4?
As a research chemical, S-4 belongs to a class of chemicals known as SARMS or selective androgen receptor modulators. Like typical androgens, SARMS bind to the androgen receptor however SARMS create selective anabolic activity.
Compared to testosterone and other anabolic steroids and pro hormones, the advantage of SARMS such as S-4 is that they do not have androgenic activity in non-skeletal-muscle tissues.
S4 was designed for treatment of conditions such as muscle wasting, osteoporosis and benign prostatic hypertrophy, using the non-steroidal androgen antagonist bicalutamide as a lead compound.
As an orally active partial agonist for androgen receptors, S-4 is effective in not only maintaining lean body mass but actually increasing it.
How does it work?
Selective androgen receptor modulators (SARMS) bind to the androgen receptor and demonstrate osteo (bone) and myo (muscular) anabolic activity.
Binding and activation of the Androgen receptor alters the expression of genes and increases protein synthesis which ultimately builds muscle.
SARMS such as S4 can cause muscle growth in the same manner as steroids, however unlike testosterone and other anabolic steroids, SARMS (as nonsteroidal agents) do not produce the growth effect on prostate and other secondary sexual organs.
SARMS not only represent a new potential treatment option for a wide spectrum of conditions such as muscle wasting diseases (from age-related to AIDS or cancer-related), but they also have immense potential for muscle building for Bodybuilders, fitness and athletes.
S-4 in particular binds to the androgen receptor in muscle and bone to a third of the affinity of Testosterone.
Uses of S-4:
Losing Bodyfat (Cutting)
Cutting is the environment where S-4 truly shines.
Certain steroids are considered “cutting” steroids such as Winstrol and Anavar. These steroids don’t offer too much in large gains in muscle mass but are very effective in leaning out the body. The SARM S-4 has very similar properties.
The presence of androgen receptors in human preadipocytes and adipocytes suggests that androgens may contribute, through regulation of their own receptors, to the control of adipose tissue development. As S-4 shows this binding affinity to the AR, it demonstrates the similar fat burning effects. S-4 also shows a decrease in LPL (lipoprotein lipase) which is an enzyme that causes lipid accumulation.
S-4 also fits into a cutting protocol for the concurrent reduction in body fat with maintenance of muscle mass in a hypocaloric environment.
One of the most disheartening outcomes of cutting is the loss hard earned muscle mass. The drop in metabolic rate and hormone levels (T3, IGF, Testosterone etc) with the lack of calories is a perfect catabolic environment for loss of muscle tissue.
As S4 has both anabolic and androgenic effects in muscle tissue, it will not only help with fat loss, but maintain and even increase muscle mass when cutting.
S-4 causes increases in vascularity and promote a very nice, “quality”, hard look to the users muscles, with little or no water retention.
In this way S-4 can be compared to Winstrol, without the harsh hair loss or extreme adverse effects on cholesterol.
Also other popular steroids/Prohormones used for cutting such as winstrol or epistane can have a notable effect on drying out of the joints. S-4 doesn’t suffer such consequences so the athlete is still able to lift heavy in order to maintain/increase muscle mass and strength.
Another advantage S-4 offers for cutting is that it doesn’t give the painful pumps associated with other popular steroids/Prohormones. Back and calf pumps are particularly detrimental for cutting as it limits the ability to perform cardio.
A dosing protocol of 50-75mg for 4-8 weeks will give good recomp effects
Diet must also be optimized to where calories are just above maintenance with at least 30% coming from lean sources of protein to get the best recomp effect.
Of course, the recomp effects could be even greater if stacked or combined with a more anabolicSARM such as Ostarine.
S-4 Dosing for cutting:
A 50mg dosing protocol for 6-8 weeks is ideal for cutting purposes for the majority of users.
However due to the vision side effects, if running at these doses some like to follow a 5 on 2 off protocol where S4 is used for 5 days followed by a 2 day break (then this cycle is repeated).