Reading Time: <1 minute Since our opening, our clinic has been producing doctor's cosmetics in-house. We purchase cosmetic raw materials from raw material manufacturers and compound them in-house to produce a vitamin C derivative lotion, which is a basic cosmetic. There are few doctors who are familiar with the basic knowledge of weight loss and manufacturing methods required for producing cosmetics, so we have released the only video in Japan, the third volume of the series ``Tips for Producing Doctor's Cosmetics for Doctors,'' so that even those without the knowledge of a private practitioner can easily produce doctor's cosmetics in-house. The advantage of producing in-house is that fine adjustments are possible, and preservatives can be used to adjust the amount of methylparaben or change to phenoxyethanol, etc., and preservative-free formulations can also be produced. General cosmetics contain various preservatives to allow a three-year shelf life. There is an advantage in being able to produce so-called ``raw'' cosmetics, and it can also be used by those who are resistant to the addition of preservatives. However, cosmetics that do not contain any preservatives are prone to oxidation and may actually be harmful to the skin, so be careful. When performing cosmetic dermatology treatment, it is essential to have a minimum level of knowledge about the ingredients and manufacturing of cosmetics.