Nandrolone Decanoate

Nandrolone decanoate is a popular steroid which is structurally similar to Testosterone, minus a carbon atom at the 19th position. This creates a steroid that exhibits less androgenic properties compared to that of Testosterone, resulting in the conversion to a weaker metabolite- dihydronandrolone, not DHT. Androgenic related side effects are still possible, but are likely to be of a less occurrence compared to that of the likes of Testosterone. Nandrolone decanoate has been shown to have a lower tendency to convert to estrogen. Estrogen related side effects are possible, but are usually confined to those who use excessive dosages of the steroid, or those who are sensitive to such side effects.

Boldenone Undecanoate

Boldenone Undecylynate 200 for IM injection, contains Boldenone Undeclynate(1,4 androstadiene-3-one17B-ol).  It was developed for veterinary use, mainly for treatment of horses.  The activity of Boldenone is mainly anabolic, with low androgic potency.  It has a very long half-life, with minimalblood levels present up to 8 weeks after its discontinued use.
 
Boldenone will increase nitrogen retention, protein synthesis, increase appetite, and stimulate the release of EPO from the kidneys.  If intended for bodybuilding, the drug is usually used in conjunction with a potent androgenic steroid such as testosterone as the "base."  Boldenone has a low rate of "aromitization", which means it deoes not convert to estrogen easily and does not cause water retnetion.

Trenbolone Acetate

Trenbolone Acetate has a binding affinity for androgen receptors five times stronger than testosterone.  Once metabolized the drug has an effect on increasing nitrogen uptake by skeletal muscle. Leading to an increase in protein synthesis.  Ancillary effects are increased appetite and a decrease in the rate of catabolism.

Trenbolone is highly effective and recommended for contest preparation.  It has been proven to show that it is not metabolized by aromatase and 5a-reductase. Therefore prohibiting its conversion to estrogen and DHT. As a result undesired water rentention and estrogenic effects are prevented.

Masteron

Masteron is a synthetic derivative of dihydrotestoterone, displaying highly anabolic effect that is resonsible for increases in muscle density and hardness. It also creates a maderate anabolic effect that creates positive nitrogen balance along with the promotion of protein synthesis. 

Masteron does not aromatize.  Therefore, water retention is not an issue and therefore provides a great contest prep drug.