The claimEvidence A · guideline-tier
Ozempic is a side-effect-free weight-loss miracle
The evidence
Within a year of stopping, about two-thirds of the lost weight comes back, so in effect it is a lifelong drug. About 70% of people have gut side effects, and loss of lean (muscle) mass is higher (STEP 1 extension, Wilding 2022).
The mechanism, in brief
Your gut already has a natural I'm full signal. What these drugs do is simple: they amplify that signal and make it last longer in the body, so you do not feel like eating as much.
Sources (3)
- Wilding, J. P. H., Batterham, R. L., Calanna, S., Davies, M., Van Gaal, L. F., Lingvay, I., et al. (2021). Once-weekly semaglutide in adults with overweight or obesity (STEP-1). New England Journal of Medicine, 384(11), 989-1002. 1961 adults with BMI >= 30 (or >= 27 with a weight-related condition) and no diabetes, randomized 2:1 to semaglutide 2.4 mg weekly or placebo, plus lifestyle intervention, for 68 weeks. Mean body-weight change -14.9% vs -2.4% (difference -12.4 percentage points); >= 15% loss in 50.5% vs 4.9%; -15.3 kg vs -2.6 kg; discontinuation for gastrointestinal events 4.5% vs 0.8%. Funded by Novo Nordisk (abstract, PMID 33567185).
- Jastreboff, A. M., Aronne, L. J., Ahmad, N. N., Wharton, S., Connery, L., Alves, B., Kiyosue, A., Zhang, S., Liu, B., Bunck, M. C., & Stefanski, A. (2022). Tirzepatide once weekly for the treatment of obesity. The New England Journal of Medicine, 387(3), 205–216. 2539 adults with BMI >= 30, or >= 27 with a weight-related complication, people with diabetes excluded; randomized 1:1:1:1 to tirzepatide 5, 10 or 15 mg weekly or placebo for 72 weeks (20-week dose escalation). Mean weight change (treatment-regimen estimand) -15.0%, -19.5% and -20.9% vs -3.1%; >= 20% loss in 50% and 57% on 10 and 15 mg vs 3%. Adverse events led to discontinuation in 4.3%, 7.1% and 6.2% vs 2.6%. Funded by Eli Lilly (abstract, PMID 35658024).
- General Office of the National Health Commission of China. (2024). Guideline for the diagnosis and treatment of obesity (2024 edition). Issued 2024-10. China's first national clinical obesity guideline. Classification for Chinese adults: BMI 24 up to 28 is overweight and 28 or above is obesity, subdivided as mild 28.0 up to 32.5, moderate 32.5 up to 37.5, severe 37.5 up to 50. Central obesity: waist circumference is normal below 85 cm in men and 80 cm in women, and central obesity is diagnosed at 90 cm or more in men and 85 cm or more in women; a waist-hip ratio of 0.90 or more in men and 0.85 or more in women also establishes it. Weight-loss target: for most overweight and mildly obese patients, at least 5 to 15 percent of body weight within 3 to 6 months, then maintained, with reassessment every 3 to 6 months. Pharmacotherapy is indicated by clinical state rather than by a BMI number: overweight plus at least one weight-related comorbidity (hyperglycaemia, hypertension, dyslipidaemia, fatty liver, obstructive sleep apnoea, cardiovascular disease) where lifestyle intervention fails to reach the target, or obesity where lifestyle intervention fails to reach the target. Five drugs are approved in China for weight reduction in adult primary obesity: orlistat, liraglutide, beinaglutide, semaglutide and tirzepatide. Surgical indications: ages 18 to 70 with BMI 32.5 or above, or BMI 27.5 or above with type-2 diabetes regardless of whether medical treatment has succeeded; also ages 18 to 70 with BMI from 27.5 up to 32.5 where medical weight reduction has failed or an obesity-related disease is refractory to medical treatment. SCOPE NOTE: chapter 12 is traditional-Chinese-medicine treatment (syndrome differentiation, daoyin exercises), which is outside this site's content scope and is not cited anywhere.