Can I mix hyaluronic acid serum and collagen and use it in my face without burning or damaging my skin?

Ok I got a client that is selling me some products for a gift for my girl. She said that she mix hyaluronic acid serum, sun block, vitamin e cream swiss collagen complex vitamin a and d and vegetal oil and and that this wont do any damages to her skin that is good for anti wrinkles. Is this true can this mix of creams can be made and use together for human skins?