A platelet-rich plasma injection is a low-risk technique that seldom results in serious side effects. Because the treatment involves a blood draw, you should stay hydrated and eat before the procedure to avoid feeling lightheaded. The most common potential side effects are bruises and inflammation at the injection site, including swelling and redness. They usually emerge right after the treatment and disappear in four to six days. Since PRP is made from your own blood, there is a minimal risk of an allergic reaction or infection. The most significant risk is from the handling of your blood. The blood removed from your body must be kept sterile. If not, major side effects, such as infection, could occur. Rare potential risks include: Bleeding Formation of scar tissue Numbing cream allergy Tissue damage Headache Infection Skin discolouration Nerve injury