... can be kept for a long time ( Notice: The lifetime of collagen is from 3 to 5 years) Cosmetology nursing knowledgeNormal SkinIt ... skin and the central panel as for oily skin and use skin care products made especially for combination skin.Sensitive skinThis type of ... of bleaching,waxing,threading,perfumes,temperature extremes,soap etc and for men sun,perfumes,shaving cream etc.Avoid products with dyes ...