Independent overview of selected studies on weight management medication, each linked to its source and summarised in plain language. We report both the benefits and the risks.
This overview is informational and does not replace medical advice. Magistra is a technology platform — we do not provide medical recommendations. Always consult a doctor.
In about a decade, the science of weight management has radically changed. Here is the timeline of key breakthroughs, each with the mean weight loss reported in the named trial.
2014-15
First GLP-1 injectable approved for weight management (liraglutide 3 mg: US 2014, EU 2015)
2021
Semaglutide 2.4 mg approved for weight management — ~15% mean loss at 68 weeks in its pivotal trial (STEP 1)
2022
Dual GIP/GLP-1 agonist tirzepatide's pivotal obesity trial published — ~21% at 72 weeks (SURMOUNT-1)
2023
Tirzepatide approved for weight management (US, November 2023)
2025
Head-to-head trial: tirzepatide 20.2% vs semaglutide 13.7% at 72 weeks (SURMOUNT-5). First oral GLP-1 tablet approved for weight management (US, December 2025)
Selected studies and reports, each linked to its source, summarised in plain language.
Head-to-head trial with 751 participants: tirzepatide produced 20.2% mean body weight loss vs 13.7% for semaglutide over 72 weeks. Gastrointestinal effects were the most common adverse events in both arms.
Review of trials of semaglutide, liraglutide, tirzepatide and exenatide lasting 40-120 weeks: sustained weight loss and favourable glycaemic control across adults and adolescents, with gastrointestinal side effects the most frequently reported adverse events.
Analysis of US Veterans Affairs health records: GLP-1 use was tied to lower risk of dementia and addiction disorders, and to higher risk of pancreatitis, kidney and gastrointestinal conditions. The release states no per-effect rate, so none is quoted here.
Narrative review of real-world studies: weight loss in everyday practice tends to be lower than in trials, approaching trial results only among highly adherent patients. 20-50% of patients stop within the first year, and doses used are often lower than those trialled. Gastrointestinal disturbances are frequent; no clear increase in severe events such as pancreatitis was seen.
Cautionary account from obesity medicine and psychiatry: these medications may be too effective for unmonitored weight loss, especially for people prone to disordered eating. The authors call for screening and continuous monitoring for disordered eating, food aversion and dehydration, and interdisciplinary care rather than avoidance of treatment.
Medical terms explained in plain language.
Problems with the stomach and intestines: nausea, diarrhoea, constipation, stomach pain. These are the most common side effects and usually improve after 2-4 weeks.
How well your body manages blood sugar levels. Good glycemic control means your blood sugar stays within a healthy range — important for preventing diabetes.
A number calculated from your weight and height. BMI 25-29.9 = overweight, BMI 30+ = obesity. It's not perfect (doesn't account for muscle), but it's the standard screening tool.
Inflammation of the pancreas (an organ behind your stomach). Symptoms: severe stomach pain that radiates to the back, nausea, vomiting. Rare but serious — stop treatment and see a doctor immediately.
A 'dummy' treatment with no active ingredient, used in clinical trials to measure how much of the effect comes from the actual medication versus the expectation of being treated.
A substance that activates a specific receptor in your body. Weight management medications activate receptors that control appetite and blood sugar, telling your brain you're full.
The time it takes for half of the medication to leave your body. This varies by drug: semaglutide's is about 1 week and tirzepatide's about 5 to 6 days, so both are injected once a week; liraglutide's is about 13 hours, so it is injected once a day. (Figures from each drug's FDA label, section 12.3.)
They mimic a natural hormone (GLP-1) that your gut releases after eating. This hormone tells your brain you're full, slows stomach emptying so you feel satisfied longer, and helps regulate blood sugar. The medication simply amplifies a signal your body already uses.
In the STEP 1 trial extension (Wilding et al., 2022), participants who had lost 17.3% on semaglutide over 68 weeks regained about two-thirds of it (11.6 percentage points) in the year after stopping. This is not a failure of the medication — it's because obesity is a chronic condition, similar to how blood pressure returns when you stop blood pressure medication. The best long-term results come from combining medication with lasting lifestyle changes.
Honestly: yes, possibly. The longest clinical trials are about 2.5 years. We don't have 10-year or 20-year safety data yet. The data we do have is reassuring — no unexpected serious risks have emerged — but science requires honesty about what we don't yet know. This is why medical supervision is essential.
The science is clear: GLP-1 weight management works, but using it safely takes honest data. Magistra publishes independent evidence — no sales, no prescriptions — so you can ask your own doctor better questions.
Last reviewed: 4 September 2026 — each card re-read against its linked source; figures the source does not state were removed. This is a fixed selection; the database itself updates daily.
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