The synthesis of nicotinamide is based on nicotinic acid as raw material. After a series of reactions, the nicotinamide obtained may contain a certain amount of nicotinic acid residue. In addition, when nicotinamide is in a non-neutral PH state, it produces niacin, which is a kind of composition. Niacin is a kind of component that can cause skin allergy. When the amount of niacinamide is added more, the sensitization rate will be increased, because the content of niacin in it also increases, thus increasing the stimulation of the skin.
If our skin can not tolerate nicotinamide (depending on the individual’s physical condition), it may cause damage to the skin. The impurity niacin in nicotinamide raw materials will cause skin irritation. People with sensitive skin may have redness, dry itching, and other allergies when using high-content nicotinamide skin care products, which is also the manifestation of what we call intolerance to nicotinamide. For people with non-sensitive skin, the first use of nicotinamide, can not be taken lightly, or it is recommended that we try, it in the trial without abnormal circumstances in normal use.