There is a cotton swab in it, one end is white and the other end is blue. Break off the blue end, and then apply white to the DNA anti-counterfeiting part of the outer packaging box, which will turn red, and then wipe it off by hand and turn it back to white. You can also call to confirm.

But I still advise LZ not to eat, and the side effects are unbearable. I dare not eat for a week.