The standard is high for holy men. The priests were instructed in much. One concern revealed is presented Leviticus chapter 21. There is a practice that has caught on in the world, and is now come into God's church. Here is the command to the priests: "He shall not defile himself, being a chief man among his people, to profane himself. They shall not make baldness upon their head, neither shall they shave off the corner of their beard, nor make any cuttings in their flesh." Verses four and five.
And if it be for pastors, then why not for the common man? And, God cares about the hair that is grown by both men and women.