In a PRP treatment, what is the main difference between the clinics or doctor? The technique/technology is different?

Like in all medical treatments the experience and training of the Dr is extremely important as well as the diagnostic tools and medical devices . In the case of PRP the device used to separate the platelets from the rest of the blood components has to be of high quality and here in the US needs to be FDA approved.

The research performed and the anecdotal evidence would suggest that thickness of hair and density can improve with PRP injections.  The number of sessions as well as the quality of PRP obtained will vary considerably physician to physician.

Hi, and thank you for your question regarding PRP treatments. While PRP treatment devices do differ as well as the protocols of board-certified facial plastic surgeons who perform the surgery, choosing a surgeon who is qualified and experienced using PRP to treat hair loss will have the most impact on getting the results you want. Select a board-certified facial plastic surgeon who can show you before and after photos of prior patients and has a long track record of successful treatments. Take your time selecting your surgeon. While PRP treatments have minimal risks, you do not want to lose time or money or get less than optimal results from a surgeon with minimal experience or does not follow best practices. Good luck! - Elbert T. Cheng, MD

Great questions.
PRP Hair Regeneration is relatively new. Though proven effective for many it has not yet been definitively demonstrated that a specific treatment is better than another. However, there are undisputed common factors required in most successful treatments. They are:
1) The type of hair loss,
     Some types of hair loss do not respond well.
2) How long the condition exists in the treatment area,
     If you haven't seen hair in the treatment area for more than 5 years, it is likely you would not have benefit. Hair loss within the past 2 years stands the best chance of recovery. Any remaining hair in treatment area will benefit greatly.
3) Density of the PRP,
      Some PRP devices are better than others. There are now too many to list, but cost remain on the high side. Minimum blood draw is generally 50mL which yields about 7 mL of high density PRP. About 0.2mL is injected per square centimeter. Larger blood draws for more PRP are possible. If they claim more PRP was obtained than 1.5mL per 10mL of blood, it is very likely you're not receiving high density PRP.
4) Area covered with a given amount of PRP,
     The smaller more concentrated the treatment area for any given amount of PRP the better. 
5) Number and frequency of treatments,
     Generally, 4 to 6 initial treatments are required. Treatments are generally spread out over 4 to 6 week periods.
6) Many physicians add to the PRP to create a cocktail. 
     Extracellular matrix is very beneficial. Small amount of progesterone is known to be beneficial as well as a few other medications.
7) At home regimen is important. Many physicians have their own cocktail.  
 In regard to type of doctor; This is not a difficult procedure, nor is the diagnosis difficult to make. I do recommend a MD or DO assess you and perform the procedure. If they have a few years in aesthetics, you'll very likely be fine. Try to get someone with at least a year of hair regeneration.
The greatest concern you likely should have is getting to the root cause of your hair loss. I have seen very few hair specialist or aesthetic physicians do anything more than treat symptoms. You need to get to the root cause. Typically, Integrative Medicine, Functional Medicine and Anti-Aging physicians will be able to address the root issues.
When the root issues are properly addressed, your hair loss will likely stop, your PRP treatment will last longer to much longer and likely be more productive than without addressing the root issues. It is a very cost effective and healthier approach than simply getting PRP treatments which only treat symptoms.  
Wishing you the best,
Arbella Sarkis, MD

Thank you for your question. You’re asking why there is such a wide difference in PRP treatments for hair loss. You can understand what the difference is when it comes to hair transplant surgery, but you’re trying to get a sense of why there is such a wide difference in PRP treatment, and who is most qualified.
I can share with you a little understanding based on my practice. A little background: I’m a Board-certified cosmetic surgeon and Fellowship-trained oculofacial plastic and reconstructive surgeon. I have been in practice in Manhattan and Long Island for over 20 years. I am also the founder of TrichoStem™ Hair Regeneration Centers, a system we developed starting about 7 or 8 years ago, derived from hair transplant surgery, using PRP and extracellular matrix to help men and women with male and female pattern hair loss non-surgically. I can speak from a perspective of a pioneer and innovator who ultimately developed a system that has been very successful.
I’ll give you a sense of how I first derived this treatment, and how I try to arrive at costs that can be reasonable. I’m a cosmetic surgeon, and I’ve been doing hair transplants for many years. With hair transplants, you have two major concerns: heal the donor area as well as possible, and get the grafts to grow and heal as well as possible. There’s a certain loss of graft viability in any hair transplant, so we used this material called extracellular matrix with PRP. A very pleasant side effect was thinning hair became thicker in a lot of our patients. From there, I asked myself if we can reproduce this effect with consistency. We started looking at different formulations and treatments, and we follow our patients very closely. We are seeing them every 3 months, then see them for years. Long story short, developed an algorithm for a system of customization of concentration, and method of delivery to maximize the growth of hair non-surgically.
With all the experience over these years, I also developed a classification system to help our patients have a sense of prognosis to expectations to what they can see with our treatment. The classification system is based on gender, age, age of onset of hair loss, rate of progression, degree of progression, and other medical variables including previous surgery, previous injections,previous treatments, as well as hormonal and other levels.
With cost, we’ve reached a point where I’m actually being very selective on who I treat because it can really take up a lot of practice resources. We treat so many patients from around the world. In a practice like mine, I do cosmetic surgery like eyelid surgery, face lifting, lasers, and injectables in addition to hair loss treatment. Developing this hair loss treatment has been so successful we developed additional offices, so we’re trying to scale in a way that is predictable and continuous. One of the things I’ve had to look at for cost has been, is it’s not just the cost of a single procedure, but rather we look at the overall management of the individual patient.
It’s very important you select a doctor you are comfortable with, and who’s going to look at your situation from a hair loss management perspective. What does that mean? A lot of my colleagues will just do an injection, then that’s it. When we see our patients, our consultations take a long time. We spend at least 30 minutes or more taking standardized digital photography, microscope photos, getting extensive medical history, and do an examination with an extensive discussion to develop a treatment plan. The treatment plan is at least one injection, maybe two injection treatments separated by 15 to 24 months. In between, we see our patients every 3-6 months, and all of is under one cost. You can imagine with every follow-up, we’re  taking photos, microscope photos, and we’re looking at and reviewing results. We’re accountable to every patient for their treatment strategy, and we work hard to make sure we get a successful outcome, or have a high probability of a successful outcome.
There are no guarantees in medicine. With all this experience, we ultimately developed a system, and that means there are others things that can be done in conjunction with Hair Regeneration to maximize hair growth for as long as possible. Remember that hair loss is hardwired in your DNA, and we’re manipulating different pathways to prolong the lifespan of the hair to maximize coverage as long as possible. So this is how the cost for our treatment was arrived at.
You have to look at the level of follow-up as an important part of your decision. When doctors try to do procedures in a more of a transactional way, often they’re just saying, “Come and get injections and we’ll see what happens.” I have seen other doctors’ photos and patients coming in with photos, and I am amazed how inconsistent these photos are, how often patients don't get photos taken and how things are done kind of halfheartedly. Ultimately, they’re paying for just seeing if something works, so it’s really important.
Don’t be fooled by one claim of better PRP compared to another. Look at the individual doctor’s real personal experience such as their before and after pictures. Look at how long they’ve been doing their treatments, and how confident they are with their treatment. The value is in the expertise, experience, accountability, and the longevity of the commitment to your individual treatment, and how many times you’ll be seen, and the availability of that doctor. Our patients have very good relationships with us. They’ll call us, and either I or my technicians will always return their phone calls.
It’s important to think about those variables instead of just thinking that one person’s PRP is better than someone else’s, because that’s just mostly nonsense. It really is about experience, expertise, and what I just mentioned. I think you have to look at it from that perspective. Again remember, hair loss is managed, and you just don't take a shotgun approach. I think a lot of doctors are offering what is a shotgun approach seeing if it works or it doesn't, and not having that level of commitment in their practice to manage patients with hair loss. I hope that was helpful, I wish you the best of luck, and thank you for your question.