We restrict this review to three major health effects associated with oral supplementation of Pycnogenol ® : (i) prevention of UV radiation-induced skin damage, (ii) modulation of skin pigmentation and (iii) improvement of skin barrier function/extracellular matrix homeostasis, because they are supported by human in vivo studies. We thus do not discuss in vitro studies on the effects of Pycnogenol ® on cultured skin cells because their clinical relevance remains to be shown, and we did not include studies on the topical application of Pycnogenol ® on mouse or human skin either [5–7] .