WEIGHT loss jabs have been a godsend for people in the UK living with obesity.
But despite 1.5 million people using the medication in a single month, say they haven’t seen the expected results from GLP-1 treatments.
Weight loss plateaus are common, but in many cases, the reasons are identifiable and fixable.
To help those facing this challenge, experts atZAVAhave broken down the mostcommon reasons the weight loss injectionMounjaromay not be working as expected – and what you can do to get back on track.
1. Incorrect medicine
Mounjaro’s effectiveness often increases as you move up the dosage ladder.
The is introduced to the body slowly (titration) to reduce side effects, eventually reaching maintenance doses of up to15mg per week.
If you’re still on a lower dose or haven’t advanced as recommended, your weight loss may be limited.
Consistency is crucial.Skipping doses, delaying titration, or not following your provider’s schedule can reduce the medication’s impact.
Many people don’t feel the full effect until eight to 12 weeks in, so patience and adherence are key.
You should give Mounjaro at least three months before judging its effectiveness.
If you’re experiencing side effects, it’s absolutely fine to remain at a lower dose for longer.
The experts advise stepping up more slowly if you’re not tolerating side effects well – there’s no need to push through discomfort.
You can always increase the dose later once your body has adjusted.
Comfort and tolerability are just as important as consistency for long-term success.
Poor diet and lack of exercise
While Mounjaro helps reduce appetite, it doesn’t override the fundamental rule of weight loss: you must burn more calories than you consume.
Even with a smaller appetite, eating more than your body needs will still cause progress to stall.
To maintain an effective calorie deficit for weight loss,menare generally advised to consume around 1,900 calories per day (down from the typical 2,500), whilewomenshould aim for about 1,400 calories per day (down from around 2,000).
Healthy diet tips:
- Be strict with calorie tracking until portion control becomes second nature
- Aim for a 600-calorie daily deficit to lose weight steadily
- Prioritise whole foods over high-sugar, high-fat
- Follow adiet plantailored to your needs, and explore healthy recipe ideas to stay on track
The experts say to also remember that initial weight loss may come fromwater, especially if you’ve reduced salt or started .
As your body adjusts, weight loss may temporarily plateau or appear to reverse.
Finally, stay hydrated and limit.
Alcohol can interfere with your metabolism and reduce the effectiveness of Mounjaro.
3. Stress and sleep issues
Chronic stress and poor are major weight loss blockers.
increases cortisol, a hormone linked to fat retention, especially around the abdomen.
increases ghrelin (hunger hormone) and decreases leptin (fullness hormone), making you more likely to overeat and less likely to move.
You’re alsomore impulsive and less motivatedwhen sleep-deprived, making it harder to stick to your and exercise routine.
As a solution, the experts say to prioritise stress management techniques (like mindfulness or journaling), and aim for seven to nine hours of sleep per night.
4. Health conditions and medications
Medical issues such as, , hypothyroidism, or insulin resistancecan all interfere with weight loss.
Similarly, certain medications (like antidepressants or steroids) may cause weight gain or inhibit fat loss.
If weight loss stalls despite doing everything right, consult your GP to rule out or address any underlying conditions.
If you have a known medical condition, it’s important to stay up to date with your routine reviews and inform your GP or specialist about any weight loss treatments you’re using.
The experts advise regular follow-up helps ensure your treatment plan remains safe and effective.
5. Unrealistic expectations
It’s natural to hope for rapid results, especially with a promising medication like Mounjaro.
But weight loss is a long-term process. Initial drops (often water weight) can be misleading.
Progress will slow, and that’s okay.
Avoid comparing yourself to others or obsessively checking the scale, say the experts.
Focus on consistency, not speed. Your journey is unique, and sustainable weight loss takes time.
6. Lack of support
Motivation by itself often isn’t enough. Without support from those who understand your goals, the journey can feel lonely and overwhelming.
The experts recommend:
- Lean onfriends and familywho encourage you
- Join online communities or local support groups, includingNHS-recommended programs
- Consider working with adietitian or coachfor personalised guidance and accountability
