[EDIT] article made here: Derma Rolling to Stimulate Beard Growth
First off, what is derma rolling?
While many of us call it derma rolling, I believe that it's based off of a brand name called Derma Roller. It can also be called microneedling. The purpose of using a DR, starting at the needle size of 0.5mm, is to produce collagen. As I mention briefly in the article Growing the Thickest Beard Possible, the tiny needles prick the lower layers of your skin, causing damage. Our body's response to this damage is to heal itself, which then produces much-needed collagen.
And... what is collagen?
Collagen is a very important structural protein. It keeps our skin elastic, youthful, and clear, as one example. Collagen is found in the dermis, whereas keratin, which is what hair and nails are made up of, is found in the epidermis. Remember: protein is good for hair.
Women microneedle, why don't they have beards?
I feel the need to add this here even though it's fairly common sense (it's been asked before). The fact that women don't grow extra facial hair after rolling their faces simply comes down to hormones. Males and females have different hormones, and most times females do not have enough of these male hormones to grow thick hair in places other than the head and pubic region. Females can and do indeed have facial hair, albeit clear and hard to see. The follicles can be there, however.
How do I derma roll?
Here's a good run down of how to roll your beard area. The video was made by BDPR member Cleric.
Now, the video does mention minoxidil as that's how many of us are utilizing the DR: we roll to produce collagen, not to increase absorption of the minox. As minox inhibits the production of collagen, we believe microneedling is a perfect tool to use in conjunction with growing your beard with minox.
So that's for people with minox. What about those of us that just want to roll?
From what I've seen, if you have a beard, it can very well help bring out more vellus hair without using minoxidil. The process takes time, as with anything, but some men report seeing new vellus hair coming out the day after rolling. How long it takes for that hair to mature, if it does, cannot be answered in a generalization.
Each individual will be different, so remaining patient and optimistic is the way to go.
Even if you wouldn't see improvement in terms of more beard hair, you will most definitely see better, clearer skin either way. Derma rollers are cheap and can be replaced after roughly 6-8 months of use.