Water is the most common plasticizer for proteinbased thermoplastics, lowering the softening point to a allow processing without excessive degradation. The biggest drawback of using water a plasticizer is that water easily evaporates from the material during use or storage. This leads to embrittlement and loss of functionality over time. In this study a series of high molecular mass plasticizers were evaluated for their efficiency in plasticizing bloodmeal-based thermoplastics. It was found that propylene glycol, di and tri-ethylene glycol were most efficient in increasing the material’s ductility, as measured by elongation at break. Using 10 parts plasticizer per hundred bloodmeal (pphBM) in combination with 10 pphBM urea gave optimal results in terms of Young’s modulus, tensile strength and processability. The mechanical properties of plasticized samples showed a stronger dependency on moisture content, compared to unplasticized samples and reached higher equilibrium moisture content in a shorter time. Using 10 pphBM TEG as plasticizer in resulted in a plastic material with a Young’s modulus of 869 MPa, tensile strength of 14.7 MPa and an elongation at break of 46%.