The claimWhat Jillian actually said

In January 2024 comments reported by E! News, Michaels described semaglutide-type drugs as yo-yo dieting, listed side effects including pancreatitis and gastroparesis, and estimated that roughly two thirds of lost weight returns within the first year after stopping. She also said she formed no judgment on people who use them and predicted public fallout within two years. She has since repeated that the drugs work mainly by reducing calorie intake.

Why it mattersWhy this matters for longevity

The regain finding is real and under-communicated, and it reframes these drugs as ongoing treatment rather than a course to finish.

Cardiovascular outcome data changes the risk calculation in a way that side-effect lists alone do not.

Muscle loss during rapid weight loss is a genuine concern that neither side of this argument usually addresses.

The evidenceWhat the science says

STEP 1 randomised nearly 2,000 adults with overweight or obesity and found a mean body weight change of about 15 percent on weekly semaglutide versus about 2.4 percent on placebo. The published one-year withdrawal extension found participants regained roughly two thirds of the lost weight and that improvements in blood pressure and lipids reverted, which supports the regain half of the claim. SELECT then randomised more than 17,000 people with cardiovascular disease and no diabetes and found a significant reduction in major adverse cardiovascular events.

What the evidence does not support is the conclusion drawn from the regain data. Weight returning after a treatment stops is the normal behaviour of a chronic-disease treatment, not proof the treatment was hollow, and the same is true of blood pressure medication. The side effects Michaels lists are documented but vary widely in frequency, from very common nausea to rare pancreatitis, and listing them together without rates overstates the typical risk. There is also no long-term data yet on decades of continuous use.

TakeawayThe honest takeaway

The practical lesson

If these drugs are being considered, treat them as ongoing therapy with a plan for protein intake and resistance training, and discuss the stopping plan before starting.

RelatedRelated habits

Resistance Training During Weight LossProtein IntakeBlood Pressure MonitoringLong-Term Weight Maintenance

Each of these is a habit you can build on its own. Explore them through the Topics index.

SupplementsThe supplement angle: Protein and micronutrients

Support a habit, do not replace one

Rapid weight loss of any cause tends to include lean mass, and appetite suppression can reduce overall nutrient intake. Adequate protein and attention to overall diet quality are commonly discussed alongside these medicines, and are a matter for the prescribing clinician rather than self-management.

Supplements can support good habits. They do not replace sleep, movement, nutrition, or medical care. Talk with your healthcare provider before starting anything new.

This is educational commentary, not medical advice, and does not imply that Jillian Michaels endorses, is affiliated with, or uses Winning Longevity or any product. We critique the claim and the evidence, not the person. Any direct quote is a placeholder until sourced. Talk with a qualified healthcare provider before changing your routine. See our health disclaimer.