Most people tend to overlook the weight of recessed wood medicine cabinets with mirrors. Avoid this costly mistake. Since you are purchasing a recessed cabinet, it means that you are cutting a hole in the wall so the product can be "inserted." The primary concern is the support of the cabinet.
If you are cutting through concrete, then the weight won't be a big problem. The concrete should be strong enough to handle most recessed cabinets. If you are cutting through a wooden wall with a hollow interior, then you need to consult with a contractor. If the recessed cabinet is too heavy, the wall alone might not be able to support the weight.