I am wanting to buy a Dermaroller, but I don't know how safe it is to buy one off the internet. Any suggestions?

In my opinion, it takes experience and background in medical skin care to both have a good result and not create problems. Sterilized rollers for example are very important, as well as treatment of any problems should they occur. I would not recommend buying one on the internet for those and other reasons.

Sterility is always an issue with these devices, especially after the first time you use it. There are two reasons you will not get the best results from
micro-needling if you are using the Dermaroller. First, rollers such as the
Dermaroller create a more erratic pattern of
"tears" through the skin due to the angle at which the needles enter
and leave the skin. This contrasts with the clean, more evenly distributed
vertical punctures seen with motorized micro-needling machines. This has been
nicely shown in studies done using clay models. Second, to get the
best results micro-needling should be combined with the application of human
growth factor serum which helps to further stimulate the skin to
trigger the release of growth factors to create more collagen and elastic fibers,
resulting in thicker, healthier looking skin. Since these serums are being introduced into the skin by the micro-needling process, they have to be sterile and designed for safe injection under the skin. Therefore, these treatments should only be done in a professional office.