How will I know that the effect will be real not just a placebo effect? 

To obtain clinically relevant results, the minimum pulsing field strength must be at least 3-5 milli Tesla (30 to 50 Gauss). In order to generate piezoelectricity inside bones and cells the field strength must exceed 10 milli Tesla (100 gauss). There are various large and expensive coil systems mounted on arms or beds, but none of these systems can generate energy higher than 100 gauss.