The depth of mesotherapy injections for the scalp can vary depending on the specific type of treatment and the area being targeted. In general, mesotherapy injections are typically administered at a depth of 4-6 millimeters into the scalp tissue. This depth allows the nutrients and medications to be absorbed into the hair follicles and scalp tissue, where they can stimulate hair growth and improve scalp health.    However, the depth of the injection can be adjusted based on the individual's hair and scalp condition, as well as the specific type of treatment being used. In some cases, a shallower injection may be used to target the surface layers of the scalp, while in other cases a deeper injection may be necessary to reach deeper layers of tissue.