Body building

I am more into regular exercise than muscle building, but if I needed to build muscle I would need bodybuilding supplements as my natural frame is slight, and I don't have any spare bulk (ie. fat) to turn into muscle.
If fitness is your thing, then moderate use of supplements with a regular exercise regime and a really good diet should help you to get to to a good level of fitness. It is important however to get good advice and take things steady. It is too easy to get carried away in the early stages and do yourself some tissue damage by going at it too hard. Muscles are developed by the existing muscles actually tearing and then reforming in a larger form. Steady tearing will be reasonably painful, but is to be expected, excessive exercise can give you long-term problems.
It is important to understand exactly what the supplements can do to your body in both positive and negative ways before you start using them.