Retin a thins the outer layer. Its good to have thick skin why men age less than women as women have thinner skin. Yes retina helps with collagen production therefore thicken deeper layer of skin but the outer thickness i find is important to retain especially if there were no wrinkles present. As thick skin holds it structure. Now if there were wrinkle already present then good to slough that off with retin aI haven't noticed any difference with my skin with oral and topical minoxidil, im using retin-a though, maybe that is helping, i do have fine lines under my eyes but that's because i stupidly applied retin-a under my eyes and it damaged the thin skin and gave me lines. Hope they go away in time.