Every now and then , especially when stressed, I get splits at the corner of my mouth ( not herpes ). The only thing that stops it and fixes it is if I take B2 , which is Riboflavin. Some compounds do not include B2. I think it is related to nerves, so maybe a compound would help you, but as all supplements, it takes time and constancy. Although with my problem, I can feel a difference in a few hours once I start taking them. It took me years to find out what to take, even a few dermatologists doubt me.