In my clinical practice, the topic of ‘what will happen if I stop my weight management medication?’ often comes up. There are many reasons why this question can arise. For one, these medications are expensive. Many people are paying out-of-pocket, and the cost continues as long as the person is taking medication. Sometimes a person has lost their health insurance, or their health insurance changes their policies and no longer agrees to pay for their medication. Some people say they want to try ‘doing it on their own’, now that they have learned about healthier lifestyles, portion sizes, and/or have been able to become more active following weight loss. Sometimes in the last few years, unfortunately, there have been intermittent shortages of medications, forcing cessation of treatment.
The first important point is that we are not curing weight struggles with medication – we are controlling them. There are many, redundant, powerful defenses in our natural human biology that vigorously defend weight. When we lose weight, there are many fullness hormones that decrease, ghrelin (our hunger hormone) which increases, and a drop in our resting metabolism. Most of the currently available weight loss medications work by decreasing appetite and/or cravings; if you stop treatment, the appetite and/or cravings return (often with a vengeance), and weight is thus regained. Clinical trials of weight management medication consistently show that when treatment is stopped, weight is regained, and health benefits of treatment regress. In our recently published Obesity Canada Pharmacotherapy 2025 Clinical Practice Guidelines (disclosure: I am the lead author), we recommend that weight management medications should be used long term, when effective, to avoid weight gain and regression of health benefits that have been achieved with treatment. In other words, it’s important to continue treatment to continue to enjoy the health benefits associated with treatment.
When we regain weight after weight loss, this unfortunately comes with unfavorable changes in body composition and metabolism. We tend to regain fat first, then muscle; weight tends to be regained above where the weight started in the first place; and, metabolism is slower than when we started (metabolic adaptation).
It’s also important to consider the potential mental health impact of weight regain. Many people who have experienced weight regain after any treatment approach often feel disappointed, even shame or self blame that this has occurred (and here we need to circle back on our natural biology driving weight regain, and that it is no person’s fault when this happens).
Is it ‘worth it’ to take weight loss medication for a shorter term, for example if a person feels they can financially afford it for a year, but not longer than that? Well, the discussion about weight regain and loss of health benefits remains the same here. Is there a health benefit to living for that year at a lower weight (akin to the ‘legacy effect’ in diabetes – good blood sugar control now prevents complications later)? We don’t know the answer to that question. The benefits of living at a lower weight and better health for that year could be offset by the unfavorable changes to body composition and often higher weight than ensues after weight loss – we don’t know where that balance pans out. (Here is where the analogy with diabetes does not apply – the diabetes physiology does not get worse if you have an improvement in control followed by a deterioration in control.) We also mustn’t underestimate the potential mental health impact of the ‘yo-yo’ weight phenomenon, even if it is expected with a predetermined plan to take medication for a certain period of time.
Is there a hope that weight management medications may not need to be taken long term in the future? Well, there are some interesting developments underway. For example, there are several potential treatments being investigated that build muscle while shedding fat (see my prior blog on one of these here). As these medications change body composition to favor higher muscle and lower fat content, could the resultant increase in basal metabolic rate and perhaps easier tendency to exercise, mean that treatment doesn’t need to be long term? We don’t yet know the answer.
We also don’t yet have data on what happens if you decrease medication (rather than stop entirely) once weight is at plateau – I have a feeling that most people would experience some weight regain and loss of health benefits with this approach (as I have most often seen in my patients who have wanted to try this), but data need to tell us whether this is the case.
BOTTOM LINE: Weight management medications are intended to be long term treatments. Clinical trials show us time and time again that if treatment is stopped, weight is regained along with a regression of health benefits. Our new Canadian Obesity Guidelines recommend using weight management medication long term, when effective, to avoid weight regain and regression of health benefits achieved with treatment. When health care professionals prescribe weight management medication, it’s therefore important to frame weight management medication as a long term treatment.
Disclaimer: I volunteered my time and received no remuneration for writing this Guidelines chapter.
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