a method of forming a collagen - thrombin hemostatic composition is comprised of forming a homogeneous aqueous admixture of collagen and thrombin at a basic ph and lyophilizing the collagen - thrombin admixture to form a stable collagen sponge having thrombin therein . the collagen utilized in the process is absorbable when placed in vivo . additionally , a lyophilized collagen product is comprised of collagen which is absorbable when placed in vivo and thrombin distributed within the collagen . the collagen product is storage stable .