DISCUSSION
Many studies have shown that HA can improve skin aging, and it also shows significant protective effects in UV‐induced photoaging models, while also showing the potential to promote skin healing.In this study, the skin hydration results of the young group were interesting, because oral HA could further improve their skin hydration level although their skin HA levels are relatively sufficient. Then, it can be speculated that oral HA may enhance the activity of AQP3 in skin,In addition, the effect of oral administration of HA on skin hydration is not monotonic. When skin moisture rises to a certain level, it will maintain at this level or slightly decrease, but would be always higher than the initial value (0 week). Apart from its intrinsic mechanism, this phenomenon may also result from the outbreak of COVID‐19. Around the 10Also, the negative impact of COVID‐19 can be seen in dermis density. The placebo group presented a significant lower value at the 12