Certain drugs have gained popularity for helping patients lose weight but many come with unpleasant symptoms
Weight-loss injections have surged in popularity and captured the public’s attention in recent months, fuelled by celebrity endorsements including former X Factor judge Sharon Osbourne and Top Gear’s Jeremy Clarkson.
The government is reportedly poised to announce trials for over-the-counter availability of certain injections. Pharmacists are set to hand out weight loss jabs on the NHS with just a short consultation needed.
Tirzepatide, known by its brand name Mounjaro, a type 2 diabetes treatment, has received approval from NICE (National Institute for Health and Care Excellence) for treating obesity in England, Wales, and Northern Ireland.
Scotland has already approved tirzepatide for obesity treatment through the Scottish Medicines Consortium, leading the way in making this medication available to patients.
Recent NHS data reveals that as of January 2025, around 500,000 people in the UK are using weight loss jabs, with many seeking advice on coping with unpleasant symptoms and side effects.
Professor Franklin Joseph of Dr Frank’s Weight Loss Clinic has gained significant attention on TikTok with his five practical tips, shared in a clip viewed over 70,000 times. We have provided a detailed look at his advice as well as a comprehensive list of Mounjaro’s most common side effects, according to the NHS.
1. Reduce portion sizes
Prof Joseph emphasises adjusting your food intake to match how these treatments work.
Eating large portions can overwhelm digestion, causing nausea. Opting for smaller, balanced meals can help.
“When you start taking treatment, remember that one of the ways it works is by slowing your stomach down,” he explained. “You’ve got to make a conscious effort to reduce your portion sizes.
“If you try and eat the same amount of food… there is nowhere for that food to go”.
2. Increase fibre intake
A common side effect of reduced food consumption is slower bowel movements and constipation.
“When you reduce your portion sizes… you’re going to reduce the amount of fibre and protein you’re consuming,” Prof Joseph said. “That volume decrease means your bowels will often become sluggish.”
Including high-fibre foods like whole grains, fruits, and vegetables can help maintain regularity.
3. Identify trigger foods
Certain foods can worsen nausea, so Prof Joseph advises identifying problem foods.
“Figure out for yourself what are the trigger foods that upset your stomach when you’re on treatment.”
Gluten-containing carbs and high-fat foods are frequent culprits, but these can vary.
Adjusting your diet accordingly is key.
4. Don’t skip meals
The appetite suppression caused by these treatments can make skipping meals tempting, but it’s important to avoid this. Skipping meals can cause blood sugar levels to drop, triggering nausea.
“Sometimes the appetite control on treatment can be so good that you forget you need to eat,” the doc noted.
Prof Joseph recommends “small, frequent, low-calorie, low-carb, and low-glycaemic index snacks or meals” to stay balanced such as a small handful of nuts or apple slices with peanut butter.
5. Stay hydrated
Dehydration is another often-overlooked cause of nausea.
“If you don’t drink enough, the dehydration will also make you feel quite nauseous and sick,” warns Prof Joseph.
Drinking plenty of water throughout the day can significantly improve your comfort.
Mounjaro side effects, according to NHS
Common side effects
- constipation
- diarrhoea
- painful stomach cramps and abdominal pain
- nausea and vomiting
- headaches
- fatigue
- hypoglycaemia (low blood sugar)
Less common side effects
- changes to your vision
- kidney failure
- pancreatitis
- problems with your gallbladder
- an allergic reaction – such as a skin reaction to where the medication was injected
