**3. General characteristics of anti-obesity medical devices**

Unlike anti-obesity drugs that act chemically through specific receptors, anti-obesity medical devices act rather mechanically. They do not have systemic absorption, specific metabolism, or receptors. Their research and development pattern follow specific models. The terminology used for medical devices differs slightly from that used for drugs (e.g., sham instead of placebo, effectiveness instead of efficacy). With some medical devices, it is not possible to use a sham for ethical and/or technical reasons. Compared to drugs, medical devices have different effectiveness dynamics. Unlike drugs, for some anti-obesity medical devices, there is no compliance issue with the device use since the device is placed in the body for several months and there is no need for repeated administration that might be affected by the subject's discipline. Because there is no systemic absorption, there are no side effects related to the impact of medical devices on different organs through the bloodstream. The regulatory systems ruling antiobesity medical devices are based on short product life cycles. The marketing and sales of anti-obesity medical devices are based on different models as compared to drugs.
