The following reasons need to be considered when the skin darkens after whitening injection: 1. When injecting whitening injections, it is necessary to inject the hypertonic liquid of whitening injections from the vein like usual infusion, and it takes 40-60 minutes each time to complete the whitening injection process. To the second injection, an interval of at least 5 days is needed. The whole process requires 10 injections of whitening injections, the interval is too short, the injection time is too short, the number of injections is reduced and other factors will affect the whitening effect, and even the problem of getting darker; 2, one of the main components of whitening injections is tranexamic acid, also known as tranexamic acid, is a coagulant drug, after intravenous injection, it will be metabolized through the kidneys, liver, if the drug content in the whitening injection is illegal or inferior products If the drug content in the whitening injection is illegal or inferior, it is easy to cause metabolic disorders in the liver and kidneys, so the skin will become darker and darker, and even damage the liver and kidney organs; 3. After improving to a certain extent through whitening injection, if the beauty lover neglects the daily basic maintenance, the skin color naturally cannot remain white and soft, because the skin will be affected by external factors, such as environment, sunlight, air, etc., and internal factors, such as endocrine, diet, etc., thus causing skin problems. Therefore, if beauty lovers want to inject whitening injections, they should choose regular institutions, use regular products, be familiar with the injection time of whitening injections, and do a good job of sun protection and skin care measures after the injection of whitening injections to maintain good results.