"Safety Studies" usually involve having small band-aid like patches placed on the back or upper arm for varying lengths of time to look for signs of skin irritation (redness, itching, or light swelling). Most of the time there is no visible reaction. During that time the participant is required to make scheduled trips into the facility for evaluation.
"Claims Studies" involve using a product at home for a specified period of time, maintaining a diary and then coming back into the facility for evaluation by the clinical investigator or for non-invasive instrument measurements on the skin.
These studies are supervised by clinical investigators, Dermatologists are available in the event of any problems that might occur. Individuals are compensated for their participation and time to the facility.