PRP for hair loss and the scalp is considered very safe because:
PRP therapy is immunologically neutral and has no danger of allergies, hypersensitivity or foreign-body reactions.
PRP is a sterile technique has to be used at each stage of PRP preparation and application. PRP is quite useful in case a patient has an underlying medical condition that makes him or her prone to infection.
PRP has a very short period of inflammation at the sites of wounds thus reducing any possible injection.