There should be no problem in drawing 60 cc of blood for the P Shot procedure, other than the cost involved. It's more important to consider how the PRP is prepared, because with the P-Shot, it's very important to have three things: (1) PRP with high concentration (over a million platelets per microliter), (2) PRP with a high purity level (less than 5-10% of red blood cell contamination), and (3) enough PRP to deliver a sufficient dose of platelets for the procedure, (for the P-Shot, we aim for 5-10 billion platelets). In general, with the P-Shot, we are looking to inject a final volume of 10 cc of PRP with a high concentration, purity and dose of platelets. This seems to be more important with the P-Shot than other PRP procedures, except maybe PRP for joint or hair restoration injections. You can't change the starting concentration of platelets in the blood draw, it's usually around 200,000 platelets per microliter. Each mL of whole blood would therefore contain 200 million platelets. If you could capture all the platelets in the starting sample of 60 mL, that means you would have 12 billion platelets. Unfortunately, no PRP system is capable of 100% capture, (also known as "platelet yield"). Yield usually ranges from 30-85% and the higher the yield, the more contaminated the final PRP usually is with unwanted red blood cells and white blood cells. There are systems which are able to remove "99% of red blood cells" but when the PRP is tested, they often lose more than half of the starting platelets. In other words, due to physics of the centrifuge, PRP systems which are good are creating high concentration do not have high purity, and systems that are good at creating high purity are not good at creating high concentration. This trade-off was shown in a review by Magalon et al in the Journal Platelets in early 2021, where they reviewed 36 different characterizations of commercial PRP systems in the scientific literature. Only 15 out of 36 systems were able to produce PRP with a concentration over 1 million platelets per microliter, which is the minimum concentration needed to meet the definition of PRP. These highly concentrating systems also had an average red blood cell contamination of around 40%, much higher than desired. On the other hand, there were two PRP systems tested which could produce over 97% pure PRP without red blood cells, but the platelet concentration was very low, even lower than the starting blood sample and over 90% lower than what would be needed to call it PRP. Testing the PRP during preparation and before use is the only way to know the concentration, purity, and dose. Ask about the system being used, make sure it's FDA and/or Health Canada approved, ask how much blood is taken to start with. This is especially important as most clinics don't offer in-house PRP testing and manufacturers' claims have not always been supported by independent testing.
