It is done in three to four sessions at two to four week intervals. Change appears between two weeks and two months and varies greatly by product, because hydrating types and collagen-stimulating types work differently. You need the product name to gauge the schedule.

Hydrating types show right after the session; regenerative or collagen types over one to two months. Hydrating types draw water in immediately, while regenerative and collagen types require the skin to respond and produce for itself. What goes in changes the waiting time entirely.

For dryness choose a hydrating type; for thin, sensitive skin a regenerative one; for lost volume a collagen type. Even among skin boosters the target problem differs, so choosing wrongly means no change even after completing the course. Confirm the product name and volume in advance.