I have read that PRP Acell only last 3 to 6 months and I have also read that it can last 3 to 6 years. So which is the correct?

I suggest seeing a dermatologist with expertise in hair loss for a formal evaluation. Any hair loss treatment takes 6 months to evaluate, so you will have to do 6 monthly treatments and then my patients cut the treatments down to every 6-8 weeks there after to maintain if the treatments are working. We combine prp with progestorone to improve results. See an expert. Best, Dr. Emer.

To the best of my knowledge, there are no formal studies or any published studies in the United States or internationally that document the longevity of PRP + Acell. Many providers may have their own opinion. Find a PRP expert.
PRPHAIRMD.COM 

Thank you for your question. With regard to PRP combined with Acell, there are no well designed studies to document whether there is increased effectiveness versus PRP injections alone. Intuitively, I believe the Acell will enhance the results. There is quite a bit of variability in response to PRP and there are a large number of PRP kits with varying concentrations. There is some general agreement that PRP concentrations of 4-6 times that in blood are most effective in hair restoration. Be sure to ask what concentration PRP the center you go to is using. Most patients respond to a series of PRP injections spaced two months apart. Another option is to add micronized fat to the PRP which is rich in stem cells. Again, no definitive studies as to the effectiveness. Since big pharma is not involved, it is unlikely there will be large multi-center studies to document efficacy. I hope this was helpful - Dr. Moore.