Guide
Semaglutide vs tirzepatide: The Science behind it
Medically reviewed by Dr. Debolina Sarkar, MD, DM (Endocrinology) · Last reviewed: 3rd November, 2026
Semaglutide and tirzepatide are two of the most talked-about medicines for weight and type-2 diabetes. This guide explains how they work, how they differ, and why they work best as part of a doctor-led plan. It is for general information only and is not medical advice.
1. The basics
Both are prescription-only medicines in India. They copy the action of hormones your gut releases after eating, which help control blood sugar, slow digestion and make you feel full sooner.
- Semaglutide acts on one hormone pathway, called GLP-1.
- Tirzepatide acts on two pathways, GLP-1 and GIP.
Both were first developed for type-2 diabetes. Some formulations are also approved for chronic weight management in adults who meet specific medical criteria.
2. Side by side
| Semaglutide | Tirzepatide | |
|---|---|---|
| How it works | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| How it’s taken | Once-weekly injection; a daily tablet form also exists | Once-weekly injection |
| Used for | Type-2 diabetes; weight management (specific formulations) | Type-2 diabetes; weight management (specific formulations) |
| Dosing | Started low and increased gradually by your doctor | Started low and increased gradually by your doctor |
| Status in India | Prescription-only | Prescription-only |
In clinical trials, both medicines led to meaningful weight loss when combined with diet and activity changes, and tirzepatide produced greater average weight loss in a head-to-head study. Individual results vary widely. The right choice, if any, depends on your health, other conditions and blood test results.
3. Who they may suit
A doctor may consider these medicines for adults with obesity, or with excess weight plus a related condition such as type-2 diabetes, high blood pressure or PCOS. They are generally not suitable for people who:
- Are pregnant, planning pregnancy or breastfeeding.
- Have a personal or family history of medullary thyroid cancer or MEN2 syndrome.
- Have had pancreatitis, or certain stomach, gallbladder or kidney problems.
This list is not complete. Only a doctor who has assessed you can decide.
4. Side effects
The most common side effects are digestive and often ease as the body adjusts:
- Nausea, vomiting or reduced appetite
- Diarrhoea or constipation
- Bloating, acid reflux or stomach pain
Less common but serious effects can include pancreatitis, gallbladder problems, dehydration affecting the kidneys, and low blood sugar when combined with some diabetes medicines. Seek medical help urgently for severe stomach pain, persistent vomiting or signs of an allergic reaction, or call 112 in an emergency.
5. Why they shouldn’t be taken on their own
- Muscle loss: fast weight loss without enough protein and strength training can reduce muscle, not just fat.
- Hidden deficiencies: eating much less can lead to low vitamin and mineral levels that only blood tests reveal.
- Weight regain: studies show much of the weight often returns after stopping, unless habits have changed.
- Unregulated sources: products sold online without a prescription may be fake or unsafe.
6. How Novity approaches it
At Novity, medication is never the starting point. Every plan begins with a doctor’s assessment and baseline blood tests. If medicine is right for you, your doctor prescribes it, monitors you with regular blood tests and adjusts your dose. Nutrition, strength training and coaching run alongside, so your results can last after treatment ends. Many Novity plans do not include medication at all.
Novity Health does not manufacture or sell medicines directly. See our Terms of Use for details.