Anabolic processes tend toward "building up" organs and tissues . These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules . Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass. Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids , which stimulate protein synthesis, muscle growth, and insulin .  The balance between anabolism and catabolism is also regulated by circadian rhythms , with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day. 
When first administering steroids, a man will have an increase in sexual function. This unfortunately is only temporary as your body becomes used to the steroid in its system. With prolonged use of a steroid, eventually, the man will feel less sexual desire, and will be less capable of maintaining an erection. Luckily, this is only temporary as well and can even be totally prevented with the use of substance such as Gonakor and HCG. Also when the steroid use is discontinued, the body’s natural level of testosterone (like the immune system) will certainly be suppressed.
You should take protein and creatine as your key supplements or a Weight Gainer product if you want to gain maximum mass. Take a whey protein shake 2 to 3 times per day with one serving being just before your Halo immediately after training and take creatine monohydrate powder or a creatine tablet (like Creakic or Creadex). Start off taking 4 servings per day for the first 5 days and thereafter take 1 to 2 servings per day (2 on training days and 1 on non-training days). To gain mass at the fastest rate, you can either do the Nitro/Cell stack (Nitro 3 times per day and Cell-Tech twice on training days and once on non-training days - always take one serving of Nitro immediately, followed by Cell-Tech right after training) OR you can use a weight gainer like Mutant Mass (along with powdered creatine) or Mass-Tech or Muscle Fuel Anabolic (which already contain creatine). If your diet is good (high in calories and protein), go with the Nitro/Cell stack, if your diet isn't so good, go with one of the mass gainers - start off with 2 to 3 scoops twice daily and increase until you are gaining the desired amount of weight per week (1/2 to 2 kilos).