This one I use 3 times a week. .25 needles do not hurt. This helps push in the product. I see a BIG significant result in the morning after. I use Vit C serum and copper serum in which I posted on this site to spread after one derma roll. 0.25 WILL NOT build collagen, but it will help get the product absorbed by the skin in which you will see the result the day after.
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