For those of you that aren't aware, most protein supplements nowadays come in the form of dried powder that you mix with water or milk to turn into a shake. You can also get some in the form of snack bars and even tablets. They started being used by top tier athletes and those wishing to push their bodies to the max to help performance on the day of competition but also pre and post competition / workout to boost performance and recovery. In recent years they have become more mainstream and have become very popular in the public eye. Large numbers of people now take supplemental protein with the aim of improving the nutrition and health.
Our bodies need protein to build muscle and repair the stress caused by working out, it's how we get stronger. The amount of protein we need varies with our body weight. The recommended guidelines are to consume between 0.8 and 1.5 grams of protein per kilo of body weight. You could push that upper limit up to 2g if you're in the midst of a particularly intensive 'bulking' program where you're looking to heap on huge volume of muscle mass. But for the genres, public your 1.5g per kg is generally plenty. The really good news is that most of us will be getting this, or even more, from our normal day to day diets. A portion of chicken breast will give you 50g or so, a few eggs will give you 20g and a glass of milk about 10g. And there you have enough protein for someone that weighs about 100kg.
So even if you think that's not enough (which it is) you can then go and have a 30g serving of protein in the form of a shake. That wouldn't be too bad but what they don't tell you is the other ingredients in a typical protein shake... And that's what you need to worry about a bit more. Here's a list of some ingredients you'll find in varying amounts in different shakes.
Sugar - up to 7 spoons of sugar (perfect if you want to put on fat or mess with insulin levels)
Artificial sweeteners (linked to cancer and brain damage)
Soy (contains phyto-estrogens)
MSG (similar issues as artificial sweeteners)
Some may find protein supplements do help them, and there are ones available with reduced artificial / bad contents, but they're not many of the mainstream ones. If you feel you need a protein shake then take you time, shop around and find a relatively natural one with low sugar levels. It might not taste gear, but it'll be better for you!
If you want our real, honest advice though - get your protein from 'real' food sources as much as you can and you'll get the added benefits of fit,aims and minerals in their actual forms too!