Hello, It is recommended to use 40k cavitation head three to four times a week, and each time for about 10 minutes on one part. And It is recommended to use the negative pressure head once a week. If you have sha on your back after doing it, do it a second time after recovery. The radio frequency head can be used every day. It is ok if the skin is slightly red. It usually takes 10 to 15 minutes. Each probe must be used with products, essential oils, lotions, creams, and gels are all OK. Do not dry burn the probe