Former FDA chief Dr David Kessler has revealed some of the terrifying side effects he suffered while on weight loss drugs, which saw him shed 60lbs. 

The 74-year-old, who served as an FDA commissioner from 1990 to 1997 and as a top Covid-19 science adviser to the Biden administration, turned to GLP-1 medications after battling his weight his ‘entire life’.

After taking the weight loss shot – he did not specify which drug he took – the 5ft 10in scientist saw his weight drop from just over 200lbs to 137lbs in six months.

Meanwhile, he also managed to cut his body fat in half, from 30 percent to 15 percent.

While he praises GLP-1 medications for their fat-busting possibilities, Dr Kessler warns that the downsides might be too much for some people to handle. 

It is estimated that roughly 15 million Americans have used GLP-1 drugs, with about 7.5 million currently on these medications.

This number is set to skyrocket further, with President Trump recently vowing to lower the cost of weight loss drugs, in line with other countries.

The average list price for a month’s supply of GLP-1 medications ranges from $936 to $1,349 before insurance coverage, but Trump’s plan is to slash these costs by up to 80 percent.

Former FDA chief Dr David Kessler has revealed some of the terrifying side effects he suffered while on weight loss drugs, which saw him shed 60lbs

Dr Kessler said he paid out of pocket for his monthly supply of GLP-1 medication. 

After starting the injections, he was blighted by some unpleasant symptoms, with one of the worst being ‘intense chills’.

He told The Washington Post that he got so cold, he had to wrap himself in an electric blanket.

Experiencing coldness is a reported side effect of some GLP-1 medications, including Mounjaro and Ozempic.

This is often attributed to reduced food intake and decreased thermogenesis (the body’s ability to generate heat).

On top of being cold, Dr Kessler revealed that he also felt generally unwell at times and hit by waves of fatigue. 

He explained: ‘I felt sick. There was malaise and occasional sharp abdominal pains.’

Lastly, in line with one of the most commonly reported side effects of weight loss medications, Dr Kessler said he completely lost his appetite and ‘felt bloated’. 

This happens as the medications work by reducing appetite and slowing down food movement in the digestive tract, which can lead to individuals feeling full for longer.

Further explaining this, Dr Kessler notes: ‘The drugs work in significant part by triggering gastrointestinal effects, keeping food in the stomach longer and generating feelings that push us to the edge of nausea – and sometimes outright nausea. 

‘They counterbalance the rewarding and addictive properties of food and reduce the food “noise,” or incessant wanting, that plays in our heads.’

Dr Kessler says he has used weight loss drugs ‘in cycles’.

He would use them for around seven months before taking a break and restarting them again and he is currently in a period where he is off them. 

Despite the side effects, the scientist is a big proponent of GLP-1 medications for weight loss and he discusses the pros and cons further in his new book Diet, Drugs, and Dopamine: The New Science of Achieving a Healthy Weight Hardcover.

The 74-year-old, who served as an FDA commissioner from 1990 to 1997 and as a top Covid-19 science adviser to the Biden administration, turned to GLP-1 medications after battling his weight his ‘entire life’. Above, pictured in 1995

He says the biggest way they have helped him, is by altering his eating patterns and many users report the same benefit. 

After stopping the medications, some patients say the drugs helped to reduce their food cravings in the long-term, altered their food preferences, and changed their grocery shopping habits. 

Dr Kessler even started eating vegetables for the first time in his life, meanwhile his cravings for fatty, salty and sweet foods ‘disappeared’. 

He says, commenting on the way his tastes have changed: ‘I have conditioned myself to eat less. 

‘When I was on these drugs, ultra-formulated foods made me feel ill. These are foods that are formulated to trigger the reward system and are the perfect trifecta of fat, sugar and salt. Also, I no longer want to eat large portions.

‘You have to relearn how to eat, and that’s what these drugs help you do.’

Looking ahead, when quizzed if he will do another cycle of the GLP-1 drugs in the future, Dr Kessler concludes: ‘We need more data on the safety and efficacy of intermittent use. The FDA should require drug companies to provide it. 

‘For me, it’s a journey. If I find myself out of balance, I certainly will consider using the drugs again.’