Hazlet was a food and drug scientist with the Food and Drug Branch of the California Department of Health Services from 1988 to 1996 and a member of the FDA's Pacific Regional Biotechnology Team from 1996 to 2003. His regulatory activities included reviewing investigational new drug applications and acting as technical liaison with field investigator staff, clinical sponsors, industry representatives and legislators. Hazlet's research interests include drug regulation, pharmaceutical policy, bioethics and technology assessment, including drug formularies. He earned a DrPH in health policy and administration at the University of California, Berkeley.