Can armpit hair be used for donor grafts for an eyebrow transplant?

It is technically possible but unless the hair is an exact match it's not advised. There's not really any reason to use it instead of using regular hair from the scalp.

It is possible to use armpit hair however not preferable.  The posterior scalp hair in the permanent zone is the most preferable donor site.  Hair from other locations have different growth cycles and may spend more time in the telogen phase (resting).

Thank you for your question. While underarm hair may be used for eyebrow transplants, I would not recommend it. First of all, the hair that grows under the arm may have a different texture growth pattern. Second, the hair cycle of the underarm hair is shorter and so these hairs may shed more frequently. This would give you less density to your results. The preferred location for harvesting hair is the back of the scalp.I hope this was helpful - Dr. Moore.