Retinoic acid cream is not a skin whitening product and does not have the effect of whitening the skin and usually does not lighten the skin on the neck. Retinoic acid cream is a keratolytic agent that induces normal keratinization of the epidermis and also removes keratin plugs, so it is commonly used in the treatment of conditions such as acne vulgaris and follicular keratosis. The drug can also affect melanin production in melanocytes, thus reducing melanin formation, and can be used to reduce skin pigmentation, but has no effect on normal melanocytes, so it should not be used for whitening. When used externally, retinoic acid cream can cause burning sensation, erythema, flaking and other symptoms of skin irritation, and should be used in accordance with medical advice. It is contraindicated for those who are allergic to the drug, lactating women, and women during the first 3 months of pregnancy. The skin of the neck is exposed to sunlight and the color of the skin is darker than other parts of the body. If whitening is needed, it is recommended to go to a regular institution and consult a professional doctor.