It is done in three to four sessions at three to four week intervals. Skin under the eye thickens over four to eight weeks, which is how long collagen takes to form as the particles dissolve. The eye area is thin, so building up across sessions rather than placing a lot at once is safer.

It fills slightly the moment it goes in, and the change in thickness appears over four to eight weeks. The hyaluronic acid included draws water in immediately, while the collagen formed as the particles dissolve takes time. So the early plumpness and the later thickness arrive at different points.

Rejuran Eye uses regenerative ingredients to help the skin recover on its own. Juvelook Eye has particles that dissolve and prompt collagen, so beyond recovery it adds a little more filling. If hollowness is part of the concern, choose Juvelook Eye; for texture and fine lines, Rejuran Eye.