Just drink bone broth (gelatin), eat liver and oysters, and vitamin c liek oranges
These are the main things the body needs to build collagen:
glycine
proline
lysine (I think the best source of lysine is actually dairy protein, so don't be afraid of dairy it's good for you. U can get a lot from fat-free skyr)
copper
zinc
vitamin c
I don't think a collagen supplement usually provides all those, and if you get them all from supplement it won't be as good as from food.
also skincare but u probably already do that bottomcroft. most important is moisturizer.
