Naturally produced in the kidneys, pancreas and liver, creatine is transported to muscle tissue where it is transformed into creatine phosphate, from which the energy molecule ATP is produced to regenerate the muscles' ability to contract and generate power during short-burst (anaerobic) activity. This translates to more productive workouts and faster muscle growth.
The exercises that allow you to use the greatest amount of weight are the ones that help you build muscle the fastest. These also happen to be the lifts that allow for the greatest percentage of increases in loading. We’re talking compound (multi-joint) exercises here, done with free weights. You’re not going to grow at nearly the same rate with a workout comprising machine exercises and isolation movements.
The last survivors of the pro-hormone supplements, which were removed from sale last January, estrogen-blocking supplements aren't pro-hormones but do inhibit the enzyme aromatase, which converts androgens into estrogens. In normal men that enzyme is ubiquitous, being present in such tissues as muscle, brain and skin. About 20 percent of the free testosterone circulating in the blood is converted into estrogen by way of aromatase.
While some supplements may in fact provide health benefits, generally speaking, consumers should purchase and use these products cautiously as they are not closely regulated by the Food and Drug Administration (FDA). Also, bodybuilders are advised to discuss supplementation plans with a registered dietitian or primary care physician prior to use to optimize effectiveness and minimize potential harmful consequences. 
For example, say you are pursuing a muscle power objective in which you have decided to perform 3 sets of 8 repetitions each. You'll want to make sure you don't add too much weight so that you are able to perform all 8 repetitions before your muscles are too tired to finish the set. Conversely you'll want to make sure you add enough weight so that you are not simply breezing past the repetitions and finish your sets of plenty of energy still left in the tank. While it may take a few workout sessions to find the right combination, once you'll do it'll be easy to monitor and increase weight as you progress.
You don’t have to, but you can. The typical creatine dose is 5 grams once or twice per day, but it’s sometimes suggested that one should “load” creatine by taking 20 to 25 grams per day for the first week of usage. This is then followed with 3 to 4 weeks of 5 grams per day, then a break for a week or two, then repeat. This may bring about more acute increases in strength and muscle size — creatine will “work” more quickly, in other words — but it’s not necessary.
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function,[572] yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.[573]