Dr. David Kessler is best known for his time as the head of the FDA and a top science adviser during the COVID-19 pandemic.
But beyond the public spotlight, he’s faced a lifelong challenge—his weight.
At 74, after decades of struggling, he turned to a new generation of medications known as GLP-1s.
These drugs, which are making headlines for their dramatic effects on body weight, helped him drop more than 60 pounds in just six months.
But the journey wasn’t smooth.
The Power—and the Price—of Rapid Weight Loss
Dr. Kessler, who stands at 5’10”, went from just over 200 pounds down to 137, cutting his body fat percentage in half—from 30% to 15%.
That kind of transformation sounds incredible, and in many ways, it is.
But as he shared with The Washington Post, the side effects were intense and at times, downright miserable.
While he didn’t name the specific drug he used, popular GLP-1 options like Ozempic and Mounjaro often come with similar downsides.
For Dr. Kessler, one of the worst symptoms was relentless, bone-deep chills. “I had to wrap myself in an electric blanket,” he said.
This drop in body heat can be explained by how the medications suppress appetite and slow the body’s heat production—something known as thermogenesis.
Feeling Sick, Tired, and Strangely Full
The cold wasn’t the only issue.
Dr. Kessler also described an overall sense of malaise, random sharp stomach pains, and waves of fatigue that made day-to-day life harder.
At times, he just felt “sick.”
Perhaps most strikingly, he lost his appetite entirely and often felt bloated.
While that may sound like a bonus for someone trying to lose weight, it came with discomfort.
These medications work by slowing down digestion and making people feel full much longer than normal—sometimes uncomfortably so.
“It’s like they push us right up to the edge of nausea,” Dr. Kessler explained.
In doing so, they also help quiet the constant mental “food noise” that tempts many people to overeat.
Resetting His Relationship With Food
Despite the side effects, Dr. Kessler is still a supporter of GLP-1 drugs—mainly because of how they transformed the way he thinks about and interacts with food.
In his new book, Diet, Drugs, and Dopamine: The New Science of Achieving a Healthy Weight, he goes deeper into the science and psychology behind it.
He says these drugs helped him break the cycle of food addiction.
Over time, his cravings for salty, fatty, and sugary foods faded away.
Surprisingly, he even started eating vegetables regularly—something he says he had never done before.
“Ultra-processed foods began to make me feel sick,” he admitted.
“These foods are engineered to hit all the reward buttons in our brain, and once those buttons were turned off, I just didn’t want them anymore.”
Taking Breaks and Listening to His Body
Dr. Kessler didn’t stay on the drugs continuously.
Instead, he used them in cycles—typically for seven months at a time—before taking a break.
He’s currently off the medication but hasn’t ruled out another round in the future.
“If I find myself out of balance, I’ll absolutely consider it again,” he said.
He’s also calling for more research into the long-term safety of intermittent use.
“The FDA should be requiring drug companies to provide this data,” he urged.
It’s a fair point—many people are curious whether they can use these drugs occasionally, rather than being on them for life.
The Bigger Picture: Affordability and Access
As of now, about 15 million Americans have tried GLP-1 medications, and nearly half of them are still taking them.
That number is expected to keep climbing—especially with former President Trump recently pledging to reduce their cost by up to 80%.
Right now, a month’s supply can cost between $936 and $1,349 without insurance.
Dr. Kessler paid out-of-pocket for his medication, which highlights another challenge: affordability.
For widespread access, pricing reforms would need to become reality.
What’s Next?
Dr. Kessler’s experience underscores both the promise and the complexity of modern weight loss treatments.
While these medications can bring real change—not just physically but mentally—they come with trade-offs that every user must weigh carefully.
As research continues and public conversation grows, one thing is clear: GLP-1 drugs are reshaping how we understand weight management.
But for people like Dr. Kessler, it’s not just about numbers on a scale—it’s about learning to eat differently, think differently, and ultimately, live differently.
Will he go back on the medication again? “It’s a journey,” he says—and he’s keeping his options open.