Can too many prp/acell injections be detrimental to hair?

Unfortunately we do not presently have a standardized protocol for the time interval between PRP treatments.However,most data and observations suggest that several weeks to months between injections is optimal.I am not aware of too many treatments being harmful.

In my opinion, you may have had a shock loss due to the excessive pressure on the hair follicles from the A cell and stem cells. It is not dependent upon the frequency of the treatment. Find a PRP expert.
PRPHAIRMD.COM 

Thank you for your question. Shock loss following PRP treatment is not very common but this kind of  diffuse hair loss occurs due to increased  the blood supply and the nutrition  in the treated area leading  to the fall of the hair in the resting phase (Telogen phase). There is nothing to worry as these hair usually come back within next 3-4 months. Please make sure that you use supplements on a regular basis and I also strongly suggest green tea at least few times a day or green tea extract. 
"This answer has been solicited without seeing this patient and cannot be held as true medical advice, but only opinion. Seek in-person treatment with a trained medical professional for appropriate care."

I have not seen any data that suggests you can have "too many prp treatments'. In my experience treatments are usually spaced out once per month.

2 reasons why you would experience shedding in your specific scenario:1.  trauma to the scalp and follicles2. testosterone in the PRP or stem cell solution higher than usual.Allow the scalp to recover and wait 6 months prior to your next treatment.  Use of multivitamins for hair and scalp highly recommended during this phase or with any PrP treatments for 3 months duration.