The present invention relates to a clottable concentrate of platelet growth factors for therapeutic and/or cosmetic use, preferably comprising the growth factors PDGF, TGF-², IGF, EGF, CTGF, bFGF and VEGF. In preferred embodiment said clottable concentrate of platelet growth factors does not induce blood cell-related transfusion reactions. The present invention also relates to a method for preparing a clottable concentrate of platelet growth factors according to the invention and comprising the steps of contacting a platelet concentrate with a solvent and/or a detergent, incubating said platelet concentrate with the solvent and/or detergent for a period of at least 5 minutes to 6 hours, at a pH maintained in a range from about 6.0 to about 9.0, and at a temperature within the range of from 2°C to 50°C, preferably within the range of from 25°C to 45°C, and removing the solvent and/or the detergent by oil extraction and/or chromatographic means.
