Safety guide · Updated August 2026
When to call your doctor on GLP‑1 therapy.
Know the difference between normal adjustment and warning signs that need medical attention.
- Usually expected, or time to call
- Keep a simple log
- Questions for your prescriber
- Physician-formulated by George W. Carroll, MD
In short.
- 1Many early side effects are a normal part of adjusting to a GLP-1.
- 2Severity and how long something lasts are what tell you to call.
- 3When in doubt, call. Your prescriber knows your history and your other medications.
Usually expected, or time to call.
A side-by-side guide to the most common symptoms.
Nausea
Usually expectedMild to moderate nausea in the first days at a dose, easing within one to two weeks.
Call your doctorVomiting for hours, or not being able to keep water down.
Dizziness
Usually expectedMild lightheadedness on standing that settles after a drink and some rest.
Call your doctorFainting, or severe dizziness that does not improve.
Tiredness
Usually expectedAfternoon dips while you get used to eating less.
Call your doctorExhaustion that stops daily life or keeps getting worse.
Stomach
Usually expectedMild bloating, constipation or loose stools.
Call your doctorSevere belly pain, especially in the upper belly or spreading to the back.
Heartbeat
Usually expectedBrief awareness of your heartbeat.
Call your doctorA racing or irregular heartbeat that lasts, or chest pain.
Appetite
Usually expectedMuch smaller appetite. That is the medication working as intended.
Call your doctorNot being able to eat or drink anything.
Signs that need a call.
For trouble breathing, swelling of the face, lips or throat, chest pain or fainting, call 911.
Stomach and pancreas
- Vomiting that stops you eating or drinking for 6 hours or more
- Severe belly pain that does not ease
- Upper belly pain that spreads to your back or between your shoulder blades
Heart and breathing
- Chest pain or pressure
- A resting heart rate over 100 that lasts for hours
- Shortness of breath
Kidneys and fluids
- No urine for 8 hours or more
- Very dark urine with severe dizziness
- Pain or trouble urinating
Neck and throat
- A new lump in your neck
- Hoarseness or trouble swallowing that lasts more than a week
Vision and nerves
- Blurred or double vision
- Severe headache with a stiff neck or confusion
Blood sugar
- If you also take insulin or other diabetes medicines: sweating, shaking, confusion or a racing heart
Keep a simple log.
Patterns help your doctor more than single moments. Note these each day for the first month.
- 1
Symptoms
Nausea, dizziness or stomach changes: none, mild, moderate or severe, and the time of day.
- 2
Food and fluid
Roughly how much water you drank and how much protein you ate.
- 3
Energy and sleep
Energy from 1 to 10, and how many hours you slept.
- 4
What helped
Whether a drink, a snack or rest made a difference.
Questions for your prescriber.
- What dose am I starting on, and when will it go up?
- Which side effects should I expect, and for how long?
- Which symptoms mean I should call you, and which mean the ER?
- Are there supplements or medicines I should avoid?
- How do I reach you after hours?
Common questions.
I feel mildly dizzy after my dose. Is that an emergency?
Usually not, but do not ignore it. Sit down and have a drink. If it gets worse, lasts more than a few hours or keeps coming back, call your doctor. If you faint, get help right away.
How long is nausea normal?
Many people find it eases within one to two weeks at a stable dose. If it is severe, stops you eating or drinking, or lasts longer, call your doctor.
I have barely eaten in a day because of nausea. Should I go to the ER?
If you can sip fluids and feel stable, call your doctor for advice. If you cannot keep anything down, feel very weak, or have very little urine, go to the ER or call 911.
Can I take supplements while I am adjusting?
Talk to your prescriber before adding any supplement. If you take blood thinners, ask your doctor first.
This page is educational and does not replace advice from your own clinician.
Updated August 2026