Dr. Margaret Hamburg, the commissioner of the US Food and Drug Administration, is stepping down from her post after nearly six years on the job. The White House is expected to announce her resignation on Friday.

Dr. Hamburg was nominated by President Obama and confirmed by the US Senate in May 2009. She is one of the longest serving FDA commissioners in history. It was her duty as commissioner to oversee public health initiatives in a wide spectrum of areas including food safety, approval of new medicines and treatments, and tobacco control. All told, the FDA regulates more than 20 cents of every dollar spent by US consumers.

Dr. Hamburg’s leadership has seen the FDA make lasting proposals in regards to health and nutrition. Under her reign, the FDA has required restaurants to visibly display calorie counts on menus and limited the use of trans-fats in food.

Dr. Hamburg has also had to face a number of major public health concerns such as the outbreak of Ebola, H1N1, and other infectious diseases, the increased prevalence of bacteria resistant to antibiotics, the rise in levels of opioid painkiller abuse, and the development of electronic cigarettes.

As expected, there has been much debate about how the FDA has handled these and other health concerned. However, no one can fail to appreciate the new measures that have been introduced over the last few years that greatly speed up the development and review of new medicines and treatments. This past year alone, the FDA approved over 50 new drugs. It is a testament to the “FDA’s innovative approaches to help expedite development and review of medical products that target unmet medical needs,” said Dr. Hamburg in a blog post.

Dr. Hamburg comes from a family with a strong medical background. Her mother, Beatrix Hamburg, was the first African-American woman to attend Vassar College and to earn a degree from Yale University School of Medicine. Her father, David A. Hamburg, was the president of the Carnegie Corporation of New York and led a distinguished career in medical and mental illness research. For her own part, Margret Hamburg graduated from Harvard Medical School and served as New York City’s health commissioner.

No replacement has been selected yet. However, insiders believe Dr. Robert Cahill of Duke University will be chosen as the next FDA commissioner. Dr. Hamburg recently appointed him to be the deputy commissioner for medical products and tobacco at the FDA.