The invention relates to molecular biology, biotechnology and medicine, and may be used to produce human growth hormone. Proposed is a plasmid DNA for the synthesis of human growth hormone in Escherichia coli cells, which is represented by the vector pET-21a(+), wherein the sequence from T7 promoter to lac operator is modified and described by SEQ ID NO : 3, with a gene insert that codes for the protein described by amino acid sequence SEQ ID NO : 1 and that has an optimised codon composition for expression in Escherichia coli cells. Also proposed is a human growth hormone production strain based on Escherichia coli cells BL21 (DE3) transformed with the plasmid DNA described. Using the proposed inventions makes it possible to achieve a significant increase in the output of the monomeric form of somatotropin, up to 80%.