All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible, Allaah willing, for a bald person to implant hair and this is not included in changing the creation of Allaah, contrarily this is bringing back what Allaah has created and this is permissible treatment because it is transplanting hair in its original place.
The evidence for this is that ‘Abdur-Rahmaan Ibn Tarafah narrated that his grandfather ‘Arfajah Ibn Sa’d had his nose cut on the day of the battle of 'Kilaab', so he used a nose of silver and his nose started to stink, so the Prophet ordered him to replace it with a golden nose". [Abu Daawood]
Indeed, doctor Sa’d Al-Khathlaan stated in his book (Rulings on transplanting hair and removing it): “With regard to transplanting hair that is intended to remove a deficiency and bringing back what Allaah has created, there is a difference of opinion among the scholars about its permissibility, and the most preponderant opinion is that it is permissible. Among the contemporary scholars who are of the view that it is permissible is Shaykh Ibn ‘Uthaymeen .”
As regards transplanting hair that is intended for beautification, then this is not permissible as this is changing the creation of Allaah, and this applies to transplanting the hair in the normal forehead as this is done to change the creation of Allaah and seek beautification and this is not permissible.
Allaah Knows best.