He received a Bachelor of Arts degree from Williams College in 1967 with a double major in Chemistry and Economics. Subsequently, he attended the University of California, San Francisco, School of Medicine. His residency was at Harvard's Beth Israel Deaconess Medical Center. After 9 years on the faculty at the University of California, San Francisco, he was the chair of the Department of Anesthesia and Critical Care and Pain Management at the University of Chicago for 16 years. He then became dean of the School of Medicine and vice president for Biomedical Sciences at SUNY Upstate.

He co-founded RealAge, a service providing personal health tools to consumers, and is chairman of the RealAge Scientific Advisory Board. He became the Cleveland Clinic’s chief wellness officer and chairman of the Clinic’s Division of Anesthesiology, Critical Care Medicine, and Comprehensive Pain Management in 2004 and was named chief wellness officer and chair of the Wellness Institute in 2007.

Dr. Roizen still practices anesthesiology and internal medicine, using the RealAge metric to motivate his patients. He has personally delivered medical care to 8 Nobel Prize winners, more than 709 ex-smokers, and over 100 Fortune 500 CEOs and CFOs. He chaired the United Way Fund Raising effort at the Cleveland Clinic in 2006 (it achieved record results, including over a 15% increase in donations to become one of the top 3 healthcare organizations in United Way Donations), and has served on the boards of five non-profit foundations. Roizen serves on the Advisory Board of HealthCorps. He served as President of the Society of Cardiovascular Anesthesiologists in 1997-8, and has won over 75 trophies in class A squash competition. He has been in the Best Doctors in America and then America’s Top Doctors (the successor book) since 1989.

Roizen and his wife, Nancy...a developmental pediatrician...live in Cleveland, Ohio. The Roizens have two children: Jenny, a Williams graduate and PhD graduate student at California Institute of Technology (she plans to start a Post Doc at Stanford in 2010), and Jeffrey, MD/PhD, received his double doctorates from Washington University in 2008, and started a residency in Pediatrics at Philadelphia’s Children’s Hospital.

Roizen is the author of the award-winning series of “RealAge” books, including: “RealAge: Are You as Young as You Can Be?” “The RealAge Makeover: Take Years off Your Looks and Add Them to Your Life;” “The RealAge(R) Workout: Maximum Health, Minimum Work;” and has coauthored, with Dr. John La Puma "The RealAge(R) Diet: Make Yourself Younger with What You Eat" and “Cooking the RealAge Way: Turn Back Your Biological Clock with More than 80 Delicious and Easy Recipes”

He has also coauthored, with Dr. Mehmet Oz, YOU: The Owner’s Manual: An Insider’s Guide to the Body That Will Make You Healthier and Younger, which was listed on The New York Times Bestseller List. He has also authored four New York Times number one bestsellers with Dr. Oz, "YOU: The owners manual" "YOU on a diet" and "YOU staying young", as well as the number two bestseller "YOU:The Smart Patient" also coauthored with the Joint Commission on Accreditation of Health Care Organizations.

Dr. Roizen has given over 1,200 lectures to professional medical groups and has been recognized with over 20 professional lectureships. He has appeared on the Oprah Winfrey Show 18 times, the Today Show 17 times, 20/20 3 times, CBN, CNN, CBS, Good Morning America 26 times, The Montel Williams Show, and PBS (three fundraising specials that have been substantially successful at raising money for PBS). He also chaired the Cleveland Clinic United Way fundraising drive in 2006 in which the Cleveland Clinic was in the top three donors in health care organizations to the United Way.He was featured in magazines including Fortune, Glamour, Cosmopolitan, Good Housekeeping, Ladies’ Home Journal, Reader’s Digest, Men’s Health, and Prevention magazines. and biography. He and Dr. Oz coauthor a daily newspaper column syndicated through over 65 newspapers in the United States and Canada.

The idea for RealAge started in 1985 when Roizen convinced a 47-year-old entrepreneur to take his blood-pressure medication by explaining he was living with the body of a 52-year-old by not doing so. The entrepreneur paid for Roizen to assemble a five-person research team and come up with similar numbers for other controllable factors that affect length and/or quality of life.

The first RealAge test debuted online in 1998.

Michael Roizen became the Cleveland Clinic’s chief wellness officer in mid-2007. The position was new for the clinic and was notable, as it made Roizen one of the top 12 executives within the health system. He is also a professor of medicine at the Cleveland Clinic Lerner College of Medicine.

Among his initiatives are starting a farmer's market near the clinic’s main campus, mentoring children in the public schools, and starting smoking cessation and weight-loss programs. He has also encouraged an expansive walking-focused health program that includes a walking program co-sponsored by Google.

He’s used also used his position at the Cleveland Clinic as a bully pulpit from which to advocate for what he sees as more effective uses of tobacco settlement funds. He criticized the Ohio government — and specifically denounced Gov. Ted Strickland as "stupid" when the state decided to take control of $230 million that had been designated for anti-tobacco programs.