Mounjaro, Ozempic and GLP-1 therapy — what's worth knowing
CheaperForDrug doesn't sell prescription medicines — but we've gathered reliable knowledge about GLP-1 therapy: differences between the drugs, side effects, lifestyle and supplements that may support treatment.
This guide is for informational purposes only and does not replace a consultation with a doctor or pharmacist — always make decisions about starting, adjusting, or stopping GLP-1 therapy together with a specialist.
What is GLP-1 therapy?
GLP-1 (glucagon-like peptide-1) is a gut hormone that naturally regulates the feeling of fullness, slows stomach emptying, and affects insulin release. GLP-1 receptor agonist drugs mimic this hormone's action — which is why they're used to treat type 2 diabetes and obesity.
The best-known preparations are semaglutide (Ozempic, Wegovy, Rybelsus) and tirzepatide (Mounjaro, Zepbound) — both are given as a subcutaneous injection, usually once a week. These are prescription-only medicines.
CheaperForDrug does not sell or compare prices for prescription drugs — our role stops at reliable education and support in the form of supplements and lifestyle habits that may accompany treatment led by a doctor.
Mounjaro vs Ozempic — what's the difference?
Although both drugs work on a similar principle, they differ in mechanism, active substance, and usage profile.
Mounjaro (tirzepatide)
Tirzepatide is a dual agonist — it acts on both GLP-1 and GIP receptors at the same time. In clinical trials it was linked to greater weight reduction than semaglutide alone, but the choice of drug should always take the patient's individual health into account.
Ozempic / Wegovy (semaglutide)
Semaglutide is a GLP-1 receptor agonist only. Ozempic is approved for type 2 diabetes, while Wegovy — at a higher dose — is approved for obesity treatment. It has a longer clinical track record than tirzepatide.
Which option is right for whom is a decision for the treating doctor, based on co-existing conditions, drug tolerance and treatment goals. Neither drug can be bought without a prescription.
Side effects — honestly, without scaremongering
GLP-1 therapy is often well tolerated, but some patients experience symptoms — especially at the start of treatment or when the dose is increased. It's worth knowing them so you can report them to your doctor and respond appropriately.
Nausea and vomiting
The most commonly reported side effect, usually easing after a few weeks. Smaller meals and avoiding fatty, heavy foods can help.
Gastrointestinal discomfort
Diarrhoea, constipation, bloating and a feeling of fullness are common, linked to slower stomach emptying. Adequate hydration and dietary fibre can ease the discomfort.
Fatigue and headaches
These can stem from the drug itself as well as a rapid calorie deficit or dehydration — pay attention to diet and regular sleep.
Loss of muscle mass
With rapid weight loss, some of the loss can be muscle mass, not just fat. Adequate protein intake and resistance training help limit this.
Report any concerning symptom — especially severe abdominal pain, persistent vomiting or signs of dehydration — to your doctor as soon as possible.
Lifestyle habits that support therapy
The medication itself is only part of the picture — diet and daily habits have a huge impact on how the body responds to treatment and how the long-term result looks.
Ketogenic diet
A low-carb, high-fat diet may help stabilise blood sugar and reduce hunger — it's worth discussing with a dietitian, especially given a reduced appetite on GLP-1.
Carnivore diet
A restrictive, animal-product-based eating pattern — some patients report good tolerance and fullness with smaller portions, but this approach needs caution and ideally individual dietary guidance.
Cold-water swimming
Regular cold exposure is sometimes cited as support for metabolism and wellbeing — start gradually and be cautious with heart or circulation conditions.
Sauna
Sauna use supports relaxation and circulation — remember adequate hydration, especially since the drug slows digestion and dehydration is easier to develop.
Sleep
Regular, sufficient sleep supports hunger and fullness hormone regulation and aids recovery — one of the most underrated elements of a weight-loss therapy.
Resistance / strength training
Weight-bearing exercise helps preserve muscle mass during weight loss — even 2–3 sessions a week make a real difference.
Hydration
With slower stomach emptying, inadequate hydration is easier to slip into — drinking water regularly through the day helps reduce nausea and fatigue.
Dietary protein
Adequate protein intake with smaller meals helps protect muscle mass and extends the feeling of fullness.
Physical activity
Daily movement — even walking — supports metabolism, mood and maintaining the therapy's results long term.
Supplements and over-the-counter products that may support therapy
The products below do NOT replace GLP-1 treatment — they can only support the body during therapy led by a doctor. They're available as dietary supplements and over-the-counter (OTC) products, no prescription needed.
Fibre
Supports gut function and may ease constipation, a common GLP-1 side effect. It also helps extend the feeling of fullness.
Protein (protein powder)
With smaller meals, protein shortfalls are easier to slip into — supplementation helps protect muscle mass during weight loss.
Chromium
A trace element often associated with supporting carbohydrate metabolism — a popular addition in supplements for people watching their blood sugar. Evidence for chromium's effectiveness here is limited — it's not a substitute for GLP-1 therapy; it's best to check with a pharmacist before supplementing.
Berberine
A natural plant alkaloid, valued as a supplement supporting glucose and lipid metabolism — increasingly used to complement a healthy lifestyle. It's not a "natural substitute" for GLP-1 medicines, and the scientific evidence is still limited — check with a pharmacist before supplementing.
Dietary supplements do not treat and do not replace pharmacological therapy — treat them as an addition to diet and lifestyle, not a substitute for a doctor-prescribed medicine.
A basket to ease GLP-1 therapy side effects
Fibre helps with constipation, electrolytes support hydration during nausea, and protein helps protect muscle mass during rapid weight loss — check the prices of these products in online pharmacies and compare the cost of the whole basket in one place.
Fibre, protein, electrolytes
This is a basket of supplements that can ease common therapy side effects — it does not contain prescription drugs and doesn't replace treatment.
Have a question about GLP-1 therapy?
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Sources
- Mounjaro (tirzepatide) — European Public Assessment ReportEuropean Medicines Agency (EMA)
- Ozempic (semaglutide) — European Public Assessment ReportEuropean Medicines Agency (EMA)
- Wegovy (semaglutide) — European Public Assessment ReportEuropean Medicines Agency (EMA)
- Saxenda (liraglutide) — European Public Assessment ReportEuropean Medicines Agency (EMA)
- Jastreboff AM, et al. — Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)New England Journal of Medicine, 2022
- Wilding JPH, et al. — Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)New England Journal of Medicine, 2021