How long will it take for transplanted body hair on head to grow?

Regarding the rate of growth of body hair follicles, it depends where on the body the hair came from. Areas like the beard grow in quickly, whereas the chest is slower. Your personal hair growth rate also plays a role as everyone’s hair grows at different speeds.
For most hair transplant cases, we don’t begin seeing results from the surgery until 6 months – 1 year post-op. That’s great that you’ve begun to see growth already. But because you are only 6 months out, we can’t evaluate the body hair growth just yet. Give it a few more months. At that time you will have a better inclination as to whether the body hair follicles were successfully transplanted.

It can take 6 to 12 months after surgery to see results.  If you are concerned it is best to contact your doctor.  Body hairs may take longer.

The growth from body hair should be the same as scalp hair but only at a 50% rate as 50% of body hairs are in telogen at any one time. This is a reality forever for these transplants.  Many doctors are not skilled in body hair transplants so growth may not always be as good anyway.