If your have fine or thinning hair, a common problem for many men, too much conditioner can weight it down but the right amount of conditioner can give your hair extra body and make it appear fuller. Too much conditioner can make your hair look oily, damp or weighted down no matter what type of hair and conditioner you use. It is important to rinse your hair thoroughly to remove all the conditioner to avoid excess buildup, oil, and grease.