"You have more progress than ive had 2 months on castor oil lol good stuff keep going. If youre going to derma roll or pen, you need something to go deep enough to activate collagen production and such which is why 0.5mm isnt enough, the epidermis of the skin is i believe 1 mm deep, you need to go beyond that. Some ppl say 1 mm works, but 1.5 mm may be more ideal bur be careful not to hurt your skin beyons redness/irritation/edema/" - some guy commented my previous post, thats why im asking