Weight-loss plateaus on medication: what they mean and what to do

A smaller body uses less energy, so the same intake that produced loss at a higher weight may now maintain weight. The body also responds to weight loss by increasing hunger signals and conserving energy. In trials of these medicines the average curve rises quickly at first, slows and then flattens, which means that stalls at some point are expected rather than exceptional.

Day-to-day weight changes by a kilogram or more because of fluid, salt, bowel contents and hormones. Short pauses of a week or two are common and often followed by a drop. A true plateau is weeks without trend change. Looking at weekly averages rather than daily readings gives a more reliable view.

• Whether doses have been missed or taken late, or the pen stored incorrectly.

• Whether you have reached the top of the licensed dose range.

• Whether protein, fluid and sleep are adequate.

• Whether new medicines, such as some antidepressants, steroids or antipsychotics, have been started.

• Whether hormonal conditions, such as an underactive thyroid, have developed.

• Whether portion sizes or high-calorie drinks have crept up.

• Whether stress, illness or menopause are changing appetite and sleep.

If you are lifting weights and eating enough protein, you may gain some muscle while losing fat, so the scale can stall even though your body is changing. Waist measurement, how your clothes fit and strength gains tell a fuller story.

A prescriber can review your dose, response and side effects, check for contributing medical or medicine-related causes, and discuss whether to continue. Product information describes when to consider stopping if the response is inadequate after a defined period at an effective dose. Increasing beyond the licensed dose range is not appropriate. Referral to a dietitian or specialist can help if progress is limited.

Weight is not the only measure. Improvements in blood pressure, glucose, mobility, sleep and mood may continue even as the scale stalls. Agree with your clinician which outcomes matter and review them together. A plateau at a lower and healthier weight can be the goal, particularly if you have reached a range that supports your health.

A simple weekly record of weight, waist, dose, side effects, sleep and any illness helps a prescriber interpret a plateau. Take the weight at the same time of day, ideally in the morning after using the toilet. Photographs of your measurements and notes on how clothes fit can be more motivating than the scale on its own.