It is advised not to share your derma roller with anybody else. Since the micro needles of the roller come in contact with your blood vessels by pricking the scalp, you should refrain from sharing the derma roller.
Make sure to use derma roller gently on the skin, do not apply too much pressure. The needles prick the scalp there might be a slight pain initially, and it is normal.
For best results, ForMen Beard Growth serum should be used regularly everyday for a minimum of three months. It should be used in the bald patches and thinned out areas on the beard.
There is no 100% guarantee. The beard growth will vary from person to person and also depends on the severity of beard thinning / patchy spots.
No, there are no side effects.