Are you all taking health functional foods for skin care?

I met up with some friends after a long time, and their skin seemed to glow, so I asked them for their secret. I usually diligently apply basic skincare, but they all agreed that I needed to take care of my skin from the inside out. When I looked in the mirror, I saw that my skin looked dull and lacked elasticity, so I thought I should try a health supplement. I wasn't really interested in this before, but it's become clear that my condition is declining, and it's becoming more noticeable. Now that I've looked into it, there are so many brands and it's hard to know which health supplement ingredients are right for me. There are so many different types, from vitamins to probiotics. Could you recommend a good starting point for someone new to health supplements? If you have a routine that you've found effective and easy to follow without side effects, please share it with us.