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.

As I know Acell is not FDA approved for hair loss and hair restoration patients in the USA. However the use of autologous PRP treatment for hair loss involve too many variables such as: centrifuge, platelets activation, platelet %recovery, treatment periods etc. There are few studies that show some results as hair loss therapy. I usually recommend PRP treatments every 2 months for 6 months then maintenance every 6 months. Minoxidil (women) and Finasteride /Minoxidil in men are great combination treatment + PRP for hair loss. Obviously there is still a role for additional hair transplant surgery  in many cases. 

Nobody knows that answer. My patients will tell you that increased shedding starts up again at some intervals after getting PRP indicating that effects are fading. Minoxidil is twice daily. Hormone blockers are once daily. Laser is three times weekly. Is it likely that PRP is potentially be 4000-5000 times more potent than these therapies when we can't even figure out yet how well it works? I'll leave that to continued and open discussion - and of course further good studies.

Questions like "how long will it last" can not be accurately answered.  There will always be some diminishing benefit from PRP placement, but realistically, how long it "lasts" depends on your expectations.  The good news is nearly all physician grade PRP systems will lead to positive results, and some will last longer than others.  You won't know what works for you until you do it.  But you know if you don't do it, you won't ever receive any benefit.  It's like not cutting your hair since you may need to do it again one day!