How much PRP can you get from 20cc blood draw for hair treatment?

It really depends on how large the area being treated it and what system your doctor uses to collect the prp.
Best,
Dr. Siman

Thanks for your question. This can be quite confusing, I know. There are over 20 FDA approved PRP preparation kits available in the United States. The concentration of PRP produced does vary based on the kit used AND the amount of blood collected. Given an average platelet count in your whole blood, there is about 2cc of "true PRP" (approx. 5-6x concentration) per 10 ml blood draw. In most cases, with the best kits, it takes a 50 ml blood draw then to  get about 10ml of PRP at that ideal concentration. Another important question has to do with the delivery of the PRP to the scalp, which is done in two ways:
1. Direct injection into the subcutaneous tissue of the scalp
2. Microneedling of the scalp, with additional PRP spread on the surface to "soak into" the dermis through the channels created by the microneedling.
It is important that the PRP be injected into the subcutaneous tissue as this is where the bulb of the hair follicle is. The second method, the microneedling, is also helpful though some feel it is not critical to the success of the procedure. 
And to answer your question directly, nothing can get 17cc of PRP from a 20cc blod draw. That is physically impossible if you define PRP as 5x concentration and you start with an average platelet count of around 240,000 for example. 
Best,
Lisa Vuich, MD