Question

Suggest an explanation for the fact that the Chemicals produced by endocrine glands are usually in the form of small molecules.

Answer 1

Endocrine glands produce chemicals called hormones which act on target organs elsewhere in the body. Hormones are small molecules (eg vasopressin) 

Answer 2

Chemical formed by endocrine glands are generally in the form of small molecules because they are secreted in a very small amount but have a very significant effect of said hormone on the body of the organism... these small molecules combine with small body cells in order to produce a chain reaction resulting in changes in the body...