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Stopping weight loss jabs can lead to rapid weight regain in one year, study suggests

Jessica Brown March 5, 2026

Study Reveals Weight Regain After Stopping Obesity Injections

A recent investigation highlights that most individuals who discontinue weight loss injections may regain a significant portion of their lost weight within a year, according to preliminary findings.

According to researchers at the University of Cambridge, participants who halted treatment for 52 weeks saw an average recovery of 60% of the weight they had initially shed. The study, published in eClinicalMedicine, underscores the potential for “substantial weight regain following cessation” of these medications.

Experts caution that if the majority of the regained weight consists of fat, patients might end up in a less favorable metabolic state than before starting treatment. Brajan Budini, a medical student at the University of Cambridge’s School of Clinical Medicine, emphasized this concern:

“Our projections indicate that although most weight is regained, some loss remains. However, we are uncertain whether the same amount of lean mass is restored, which could impact long-term health outcomes.”

Weight loss injections, classified as GLP-1 receptor agonists, function by replicating the effects of the hormone GLP-1 to manage blood sugar and insulin. Originally developed for type 2 diabetes, drugs like semaglutide (Wegovy) and tirzepatide (Mounjaro) are now employed by the NHS to combat obesity.

Separate research involving over 600,000 US veterans with type 2 diabetes reveals that these injections might also aid in preventing substance abuse. The study found a 14% lower risk of developing substance use disorders (SUDs) among those without prior addiction histories. Additionally, veterans on GLP-1 treatments showed reduced rates of cannabis use (14%), alcohol dependence (18%), cocaine misuse (20%), nicotine addiction (20%), and opioid abuse (25%) compared to peers on alternative diabetes medications.

For individuals already struggling with addiction, the injections were linked to a 31% decrease in SUD-related emergencies, hospitalizations, and fatalities. The findings, published in the British Medical Journal, also noted a lower likelihood of drug overdoses and suicide attempts in this group.

While the US study focused primarily on older men, similar outcomes were observed in women, suggesting broad applicability. Researchers advocate for additional studies to determine how these injections influence weight composition during and after treatment.