To some extent vitamin C has a whitening effect. Vitamin C whitening works by removing free radicals. When the body produces free radicals, our melanocytes work twice as hard to fight off free radical damage to the skin. This time vitamin C scavenges free radicals and reduces the stimulation of free radicals on melanocytes, so naturally it can somehow reduce the production of melanin. But we can’t blindly exaggerate the role of vitamin C. Because vitamin C is only one of the many aspects of whitening, whitening also need to directly inhibit melanin production, such as Tranexamic acid, arbutin, resorcinol/hydroquinone is this role, so these substances whitening effect is better. Vitamin C used blindly can have numerous side effects, such as causing scurvy after stopping the drug and increasing the risk of urinary stones. So always use it under the supervision of your doctor. All the above medications should be used under the supervision of a doctor.