Herrera has responded with his own lawsuit just one week later, according to the Los Angeles Times.
His office filed a complaint Monday, accusing Monster of marketing the company's energy drinks to children too young to consume the levels of caffeine the drinks contain.
The statement said Monster violates California law by "marketing highly caffeinated energy drinks to children as young as 6 years old."
Herrera's office has been investigating Monster's marketing and sales practices for "months," according to the statement, and the office been in negotiations with Monster regarding its youth-targeted advertising.
Today, Monster voiced the concerns stated in its initial complaint: The company says Herrera is intruding on the Food and Drug Administration's authority -- and that Herrera is "motivated by publicity rather than science."