Laura was previously the editorial assistant on Healthy Food Guide. She is now a freelance journalist specialising in health, wellbeing, food & travel.

If exercising regularly and eating right isn’t shifting the pounds, could your medication be to blame?


It’s thought around 10–15% of weight management issues may be linked to medication. ‘If your medication is causing weight gain, it will often be quite gradual and occur over the first few weeks and months of taking it,’ says HFG expert and GP Dawn Harper. If, however, you’ve been on a drug for many years before your weight changes, it’s unlikely to be due to the medication.’

Why the link?

We know antidepressants, such as amitriptyline, or steroids can increase appetite by affecting the areas of the brain that control feelings of hunger and satiety, while people taking insulin may at times end up eating more than they need to prevent blood glucose levels falling too low. Beta-blockers for hypertension can typically make you very sleepy, so you feel too tired to be as active as you need to be.

Reassuringly, this doesn’t have to be a permanent problem. ‘Weight gain from medication does plateau, and the amount of weight put on varies from person to person,’ explains Dawn. ‘However, with my patients I drill down to find out when the weight gain occurred. We need to be honest about other factors in our lifestyles, too, and work out whether any changes are occurring that could be the real cause of the weight gain.’

Pinpoint the problem

If you suspect your medication is at fault, don’t stop taking it, as doing so could have serious consequences. ‘There are certain medicines you should never stop abruptly,’ says Dawn. ‘Your GP will be able to work out whether your weight gain is down to medication or something else.’ Make an appointment, then go along armed with the facts:

Check the side effects By law, all prescription medicines must contain a Patient Information Leaflet (PIL), so you can check if weight gain is a listed side effect. If you don’t have a copy of the leaflet, you can go to, search by medicine name, then click on ‘patient information’.

Keep a food and exercise diary It will be helpful for your doctor if you have a record of the food you’re eating and the exercise you’re taking, and note down your weight over a few weeks (using the same scales each time). This will give your GP an overview of your current lifestyle, which will help with your medication review.

Your doctor will be able to assess your situation and may be able to prescribe an alternative medication or reduce your dose. They’ll take into account other factors, such as family history and lifestyle, that could be affecting your weight. If for any reason, your doctor can’t change the medication you’re on, ask to be referred to a registered dietitian to discuss any changes you may need to make to your diet. Alternatively, find one at or

Help with managing your weight

There are a number of ways a dietitian can help you manage weight gain from medication, and one of the first pieces of advice will often be to keep on top of hydration levels. ‘Being well hydrated can really help to manage your appetite,’ says dietitian Lucy Jones. ‘Make sure you’re drinking enough through the day. Always carry a bottle of water and keep up your tea intake.’

Dietitians use coaching techniques to help people manage an increased appetite, where medication has affected those messages to the brain. It’s important to recognise the difference between hunger and appetite, explains Lucy (in other words, the need for food versus the desire to eat), and which foods can help to make you feel fuller. The techniques used will probably be similar to those used to tackle any unwanted weight gain, she adds. But it’s the support you’re offered by a qualified dietitian that will make managing it easier.

Drugs that can trigger weight gain

People react to medications in different ways, so there isn’t a definitive list, but those known to cause problems with weight gain in some people include:

Amitriptyline – for mood disorders

Oral steroids (corticosteroids) – for rheumatoid arthritis, for example

Valproate or gabapentin – for epileptic seizures and migraines

Insulin, insulin secretagogues or thiazolidinedione therapy – for diabetes

Hypertensive beta-blockers – for high blood pressure

Antihistamines – for allergic conditions