Semaglutide Explained: GLP-1, Appetite and Clinical Evidence

Peptide Library

Semaglutide is a peptide medicine that acts at the GLP-1 receptor. It is discussed in both diabetes care and weight-management research, but its brand names, formulations and authorised uses need to be distinguished. [1]

What does GLP-1 mean?

GLP-1 stands for glucagon-like peptide-1. Semaglutide activates its receptor and influences pathways involved in glucose regulation and appetite. Its effects include supporting insulin release and reducing appetite. The clinical outcome depends on the person, the medicine and the treatment setting. [2]

What has been studied?

The STEP 1 trial investigated semaglutide alongside lifestyle intervention in adults with overweight or obesity who did not have diabetes. Participants were followed for 68 weeks in a randomised, placebo-controlled design. This type of trial helps distinguish a treatment’s effects from changes that might occur with the comparison intervention alone. The study involved a specified formulation and protocol, so it cannot be used as a blanket endorsement of every product marketed as semaglutide. [3]

Ingredient and brand are different

Semaglutide is the active ingredient. Ozempic and Wegovy are brand names for medicines containing it; their indications and presentations differ. Novo Nordisk’s South African Wegovy information lists registered prescription pen presentations. Exact local indications, contraindications and instructions should be read in the current South African professional information. US indications should not simply be copied into a South African treatment claim. [4]

What about adverse effects?

Wegovy’s prescribing information describes gastrointestinal effects and precautions including pancreatitis, gallbladder disease, dehydration-related kidney injury and severe gastrointestinal reactions. It also addresses risks with certain concomitant diabetes medicines and carries the US thyroid C-cell tumour boxed warning. These considerations help explain why suitability cannot be decided from an article or a before-and-after photograph. [1]

Why formulation matters

A registered medicine’s evidence relates to its actual product. SAHPRA has taken enforcement action involving unregistered semaglutide and combination formulations. A shared ingredient name does not establish the same quality, approval or clinical performance. Articles should describe the science while keeping these product distinctions visible. [5]

Frequently asked questions

Does semaglutide act at the same targets as tirzepatide?

They share GLP-1 receptor activity, but tirzepatide also activates GIP receptors.

Are all semaglutide products interchangeable?

No. Formulation, presentation, authorised use and product registration matter.

Does this guide recommend a dose?

No. It explains the compound and evidence; prescribed treatment requires product-specific advice.

Explore related articles

Sources

  1. DailyMed: Wegovy prescribing information, June 2026
  2. SAHPRA: semaglutide mechanism FAQ; historic registration text not used
  3. Wilding et al., 2021: STEP 1 semaglutide trial
  4. Novo Nordisk South Africa: registered Wegovy presentations
  5. SAHPRA: enforcement concerning unregistered GLP-1/GIP products, May 2026

Research checked: 11 October 2026. Educational information; not a diagnosis, prescription or dosing guide. Prepared for SkyCor with AI-assisted research and drafting; not independently medically reviewed. Approval information relates to the named products and jurisdictions, not every product carrying the same ingredient name.

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