In the case of hair regeneration the addition of calcium gluconate is not required. The amounts of PRP are so small in each injection site that platelets will activate as soon as they come into contact with certain proteins or tissue. Prior activation also starts the clock ticking on all the beneficial factors of the PRP and clotting. Essentially creating a surge that may or may not be utilized by the cells due to clotting that keeps the PRP bound up in a smaller location. As you might imagine, absorption of the clot by the body may well exceed the life of the activated platelets which can be as little as 7 - 8 hours. Better to simply let the PRP migrate and activate naturally when and where needed. The size of the needle has very little to no effect on the activation of the platelets. Only comfort of the patient. The most crucial element in regard to PRP hair regeneration is how the PRP is prepared. Not all systems and kits are created equal. There can be significant differences in the density of platelets and other beneficial growth factors. The simple gel tube systems seem to provide the lowest concentration with ratios in the area of +/- 1:1. The best system to my knowledge and the one we use is the Emcyte system. It provides an average of 7:1 ratio which is quite dense and provides for superior results. If the PRP is combined with an enhancing biologic, the PRP is generally activated very quickly as they come into contact with one another. The biologics tend to stay around for a much greater time and continue to provide their benefits much longer than the PRP. Thus you obtain an enhance result. Biologics are not created equal in efficacy or price. Popular biologics include Acell (Matrastem), Umbilical Cord Stem Cell products, Amniotic Products, Exosome Products, Placental Matrix and other beneficial tricks such as adding Peptides or Progesterone. Best to investigate which biologic or other enhancing product your provider is proposing if seeking enhanced PRP hair regeneration treatments. The treatment area should be fairly confined as well. Treatment over large areas with a single blood draw will produce diffuse results that generally appear lack luster in their overall outcome. Number of treatments is important. Generally, 4 treatments is the minimum and 6 treatments is much better and generally accepted as the standard. Treatment should be spread out over 4 - 6 weeks. Don't forget the maintenance treatment every 6 months. Time since you last saw your hair is important. If you haven't seen it for a couple years, beneficial results tend to fall off quickly as time progresses. If scaring of the scalp has occurred, results can be significantly impaired. Scarred tissue has very poor blood circulation. Biologics will definately be required as well as additional treatments. The goal will be to normalize the scared tissue into healthy tissue that can support follicles. This is important even for more successful hair transplant sites. Checking your metabolism and hormones is very important. More often than not I find something that can inhibit the PRP treatment and was a significant contributing factor to the hair loss in the first place. Even in your problem is genetic, it is important to check these. Pre and post treatment care and supplements will also impact your results. Hope I have helped. Warmly, Arbella Sarkis, MD