cool mamaaa says:

There are thousands of supplements out there from one a day vitamins to the stuff only pro’s need. SO this is kind of a broad question.
Pros- They can give your body vitamins, minerals and other things it needs that you don’t get from normal eating.
They can help you build muscle or lose fat.
They can give you energy.
Cons- Some supplements are bogus and don’t help you at all. Stay away from any “miracle” supplements online. Nothing out there is the end all cure all.
The FDA does not regulate supplements so we end up with things like ephedrine, which has killed people.
Some supplements add to chemicals your body already produces. Creatine is an example. It can help you build muscle but after 3 or 4 weeks, your body will start producing less. You have to cycle the creatine, taking time off or your just wasting money.
My best advice is to go to a health store (like GNC) and tell them what your looking to do. They’ll be able to guide you to the supplements you need. There are a LOT of choices and it can get expensive so it’s best to figure out exactly what you need so you don’t blow your money.
If your looking to gain, go with whey protein. Down one shake before you work out and another when you finish.
I haven’t tried it, but I have heard a lot of good things about NO supplements. They give you a boost of energy and help you focus for better workouts. No-Xplod seems to be really popular but it ain’t cheap.