There are side effects of cosmetic injections, which may include allergic reaction, infection, uneven face parts, etc. 1. Allergic reaction: after the injection of cosmetic injection may appear allergic reaction, although the probability is very low, but once it occurs, the minor may appear local redness, swelling, pain, itching and other symptoms, the serious may be life-threatening. 2. Infection: after the injection of cosmetic needles, local needle eyes will appear, it is best not to get wet within 24 hours, otherwise it is easy to become infected. 3. Uneven face: within 7 days after the injection of cosmetic injections, it is best not to massage and rub the face, to avoid the spread of the medicine to the muscles that should not be spread inside the face, resulting in uneven face, such as the corners of the mouth have a slight crooked and so on. To inject cosmetic injections, it is recommended to visit a regular hospital to avoid adverse consequences.