Why is my GLP-1 no longer working?
9 causes of a plateau on Ozempic, Wegovy or Mounjaro — and what you can do about it.
Updated 28 May 2026 · Medically reviewed by a BIG-registered doctor
Important: most plateaus on GLP-1 are physiological and solvable. A plateau is not a failure of the medication — usually it is your body adapting, and a targeted change in dosage, nutrition or exercise is enough to get moving again. Never stop medication on your own; always discuss it with your doctor first.
The 9 most common causes
1. You are on your starting dose and have got used to it
GLP-1 medication is increased in steps. The starting dose (e.g. semaglutide 0.25 mg) is deliberately low to limit side effects — but delivers little extra effect after a few weeks. If you have not been stepped up according to schedule, you plateau sooner. What to do: discuss with your doctor whether a dose adjustment according to protocol is possible.
2. Your body is in metabolic adaptation
With every bit of weight loss your resting metabolism drops: a person of 90 kg burns more than the same person at 75 kg. Your calorie deficit automatically shrinks as you lose weight. What to do: adjust your calorie intake slightly further (not drastically — that increases muscle loss), and focus on quality (more protein, fewer fast sugars).
3. Too little protein, too much muscle loss
With rapid weight loss, up to 30% of the weight lost consists of muscle mass if you do not get enough protein. Muscle loss slows your metabolism even further. What to do: aim for 1.6–2.2 g of protein per kilo of body weight per day. A protein shake on a GLP-1 programme is practically indispensable.
4. No strength training (only cardio or nothing)
Cardio burns calories but does not build muscle mass. On GLP-1, strength training (2-3× per week, 30-45 minutes) is the strongest anti-yo-yo tool. What to do: start with light strength training — even bodyweight exercises — and build up. A coach can draw up a plan that is realistic.
5. Hidden calories in drinks and small snacks
GLP-1 dampens hunger strongly, so people often think they are 'not eating anything'. But coffee with milk, small handfuls of nuts, a glass of wine in the evening — that can add up to 400-600 kcal/day without noticing. What to do: log everything for one week, including drinks. That is often where the leak is.
6. Sleep and stress sabotage your hormones
Poor sleep raises ghrelin (hunger hormone) and cortisol (stress hormone). Both work against GLP-1's appetite-suppressing effect. Chronic stress also disrupts your insulin sensitivity. What to do: 7-8 hours of sleep per night, limit screen time before bed, and build in moments to de-stress (walking, breathing exercises).
7. Underlying medical cause
Hypothyroidism (underactive thyroid), insulin resistance, sleep apnoea or certain medication (antidepressants, beta blockers, antipsychotics) can block weight loss. What to do: have your blood values checked — thyroid, glucose, insulin, vitamin D, iron. At Go Leaner this is a standard part of monitoring.
8. Hitting a plateau is normal and temporary
Between month 3 and 6, many people experience a temporary plateau of a few weeks. The body is settling in. No reason to stop or increase the dose out of panic. What to do: wait 2-4 weeks, stay consistent with nutrition and exercise, and then re-evaluate with your doctor.
9. Your medication may be inferior or counterfeit
Ordering online outside recognised Dutch pharmacies sometimes results in counterfeit products or incorrectly stored medication. What to do: only buy via a Dutch pharmacy that your clinic works with. If in doubt: have the pen inspected by your doctor.
When to contact a doctor immediately?
- Persistent severe nausea or vomiting for more than 2-3 days
- Sharp upper abdominal pain — may indicate pancreatitis
- Signs of gallstones (pain in the upper right, fever)
- Sudden mood changes or low mood
- Dizziness when standing up, fainting — may indicate dehydration
Break through the plateau with the right approach
At Go Leaner we combine medication with coaching and blood-value monitoring. Plateau? Then we look together at dosage, nutrition, exercise and underlying factors.
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