Dimethylisosorbide is a clear, slightly oily liquid that acts as a solvent and can be plant-based or synthetic. It is also used to reduce the thickness of products, such as keeping a liquid in its liquid form rather than returning it to a lotion (or, in cosmetic chemistry parlance, a thicker emulsion). Another function of this ingredient is to allow controlled, sustained delivery of key ingredients such as antioxidants, so they could theoretically provide stronger benefits. https://www.paulaschoice.com/ingredient-dictionary/ingredient-dimethyl-isosorbide.html?q=Dimethyl%20Isosorbide&fdid=ingredients