The invention relates to an intra-articularly administrable growth factor concentrate derived from approximately 250 x106 to 5000 x106 human platelets per ml for treating tendinopathies. The concentrate comprises approximately 900 to 2000 pg/ml of Epidermal growth factor (EGF), 30 to 300 pg/ml of Vascular Endothelial growth factor(VEGF), 20 to 100 pg/ml of Basic fibroblast growth factor (b-FGF), 40000 to 120000 pg/ml of Transforming growth factor-β (TGF- β) and 200000 to 600000 pg/ml of Platelet Derived growth factor-AB (PDGF-AB).