Independent information website. It does not replace a medical examination or advice.
Side effects and warning signs

GLP-1 side effects: common problems and warning signs

The most common adverse effects of injectable GLP‑1 and related medicines involve the digestive system. They often appear when treatment starts or the dose increases, but should not simply be ignored.

Verified sourcesNo medicine salesA doctor decides

Nausea, diarrhoea, constipation, vomiting and abdominal discomfort are commonly described in product information. The frequency and important risks differ between medicines, so a general internet list cannot replace the leaflet for the prescribed product.

What to know

What to know

01

Repeated vomiting can cause dehydration and may require medical advice.

02

Severe or persistent abdominal pain needs prompt assessment.

03

A serious allergic reaction or sudden change in vision requires urgent medical attention.

What a doctor assesses

What a doctor assesses

A medicine is selected only after an individual medical assessment. BMI is one part of the decision, not the decision itself.

  • BMI, waist circumference and weight history
  • Related conditions and recent test results
  • Current medicines, allergies and contraindications
  • Previous treatment, goals and ability to attend follow-up
Safety and responsible access

Safety and responsible access

Prescription weight-management medicines can cause adverse effects and are not suitable for everyone. The exact risks, dose escalation and monitoring differ by product. Read the current package leaflet and contact a doctor or pharmacist if anything is unclear.

FAQ

Questions about this topic

Should I stop treatment when nausea appears?+

Do not make the decision from a website. Contact the prescriber for advice, especially if symptoms are strong, persistent, prevent drinking or are accompanied by warning signs.

Can I decide from this page whether the treatment is suitable for me?+

No. This page is educational. A licensed doctor must consider your history, other medicines, contraindications and local product information.

Official sources

Official sources

EMA · medicine safety and product informationOpen official informationEMA · semaglutide and NAIONOpen official informationEuropean Medicines AgencyOpen official informationYour Europe · cross-border prescriptionsOpen official information

Sources reviewed 12 August 2026.