When to call your doctor on GLP-1 treatment: a plain-language guide
Most side effects are mild and expected. This is the short list of what isn’t — and what to do about each.
By The Vive Team
August 2026 · 5 min read
The hardest part of starting a new medicine is calibration: you do not yet know what normal feels like, so everything feels like it might be a problem. Here is the triage, in three tiers.
Tier 1 — Expected, and usually settling
These are the common gastrointestinal effects of this drug class, especially in the first weeks and after each dose increase:
- Mild to moderate nausea, particularly in the day or two after a dose.
- Reduced appetite and feeling full sooner. This is the intended effect, not a side effect.
- Constipation or diarrhoea.
- Burping, mild bloating, some abdominal discomfort.
- Tiredness during the adjustment period.
Practical management is in managing side effects, and a lot of it comes down to hydration and fibre. These usually ease as your body adjusts.
Tier 2 — Message your care team
Not emergencies, but do not just endure them:
- Nausea or vomiting severe enough that you cannot keep fluids down, or that is interfering with eating properly.
- Side effects that are not settling after a few weeks at the same dose.
- Constipation that has not responded to more water and fibre.
- Losing weight faster than feels right, or struggling to eat enough to function.
- Feeling persistently unwell, weak or dizzy.
- Any new symptom you are unsure about, including ones not on this list.
A dose can be held or stepped back down — that is a normal adjustment, not a failure. You can reach the team from the Care section of your dashboard, or book a consultation.
Tier 3 — Seek medical care the same day
Do not wait for a reply to a message. Go:
- **Severe or persistent abdominal pain**, especially radiating to your back — possible pancreatitis.
- **Severe upper-right abdominal pain**, particularly after a fatty meal, or yellowing of the skin or eyes — possible gallbladder problem.
- **Signs of an allergic reaction** — swelling of the face, lips, tongue or throat; difficulty breathing; a severe rash.
- **Persistent vomiting** with signs of dehydration — very little urine, confusion, racing heart.
- **Symptoms of low blood sugar** if you also take insulin or a sulfonylurea — shaking, sweating, confusion, palpitations.
- **A lump or swelling in your neck**, hoarseness, or difficulty swallowing.
Tell whoever treats you that you are taking a GLP-1 medicine. It changes what they consider.
The rule when you are unsure
If you are genuinely uncertain which tier something belongs in, treat it as the higher one. Nobody on our side will think less of you for checking, and the cost of asking early is far lower than the cost of waiting.
Read the full Important Safety Information. If you think you are having a medical emergency, seek emergency care — do not use the dashboard.
// References
- 1.Product prescribing information for GLP-1 receptor agonists (adverse reactions; warnings for pancreatitis, gallbladder disease, hypersensitivity, thyroid C-cell tumours; hypoglycaemia risk with concomitant insulin or sulfonylureas).
- 2.Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384:989–1002. View study →
Provided for education only. Trial averages describe study populations, not any individual’s expected result. This is not medical advice — GLP-1 medication is prescription-only and outcomes vary.
Medically reviewed by Vive’s licensed physicians. Meet the clinicians →
Curious what’s right for you?
Take the 3-min quiz →