Retinol is the only active ingredient that acts on collagen in three steps:

• repair (the damage caused on fibers over time)
• stimulation (of new fibers of collagen)
• protection (once it inhibits the collagenase).

In addition, it regulates the altered activity of the melanocyte thereby reducing spots on the skin and stimulates the proliferation of epidermal keratinocytes (exfoliating action).
Nicotinamide reduces the transfer of melanosomes to keratinocytes (depigmentating action), stimulates the proction of new collagen, protects the skin from free radical activity, regulates the synthesis of ceramides (hidrating action) and prevents inflammation of the skin.