The first is the freckle effect, which is a hard indicator. Products that can't see the effect are first labeled as useless and will not be accepted by the public.
The second is safety. Although a freckle removing product is effective, if it is at the expense of health, it will definitely not be accepted by the public, and it will not be worth the candle.
The third is the form. Whether the product has been strictly examined and approved by the state, the safety and quality are guaranteed, and whether there is a property right patent is the only standard for safety, and it is also the most important standard for judging the quality of freckle products.