Most of these products are testosterone supplements or testosterone gel, as these are the only products that have been tested to be testosterone based.
Many of the testosterone products on the market today are very expensive and contain very few ingredients. When you look at this page, there will be many things you need to look for if you're on a budget, but it will not be a complete guide to all the things that you can buy. So if you know of any other sites that I have missed, or if you have any questions, please post them in the comments and I will try to address them. The most important thing is that you don't take testosterone supplements to increase your muscle mass. The products that are available on the market are not testosterone based and therefore they will not build muscle. You should look for testosterone based testosterone supplements that will build muscle and increase strength, speed and endurance in general. In most cases, these will be the ones that contain testosterone, but there are other things that you will need to look for. The products on the market are expensive and it is wise to avoid them.