Starting a GLP‑1 medicine
The first few weeks bring questions about the medicine, the pen and what to expect. These guides bring together the leaflet information on starting treatment, with places to begin for your next conversation with your prescriber.
A place to start
New to treatment?
Begin with the first dose, the pen and the side effects described in the leaflets.
Your first weeks on a GLP-1Looking ahead?
Compare the dose steps described for each injected medicine.
How the doses step upPreparing for an appointment?
Find the health conditions and other medicines the leaflets ask you to mention.
What to tell your doctor
Find a guide
Search by medicine, symptom or question.
7 guides in starting treatment
Your first weeks on a GLP-1
What the leaflets say about starting: the low first dose, the side effects most likely early on, and the pen.
Checked against 10 sources on 12 October 2026
Read the guideWhere to inject, and how to rotate
Stomach, thigh or upper arm: where each leaflet and label says to inject, and how to rotate the spot each week.
Checked against 6 sources on 12 October 2026
Read the guideCommon side effects, and when to get help
The common and serious side effects the NHS lists for semaglutide and tirzepatide, and who to contact.
Checked against 4 sources on 12 October 2026
Read the guideDo side effects ease over time?
Which side effects the leaflets say usually ease, what the NHS says to do meanwhile, and when to get help.
Checked against 6 sources on 12 October 2026
Read the guideHow the doses step up
How Mounjaro, Zepbound, Wegovy and Ozempic doses step up, from the starting dose to the top one.
Checked against 4 sources on 12 October 2026
Read the guideHow a weekly jab builds up
Why Mounjaro and Ozempic take about a month to settle, how soon they peak, and how long Ozempic lingers.
Checked against 5 sources on 12 October 2026
Read the guideWhat to tell your doctor
The things the leaflets ask you to raise with your doctor before and during treatment, word for word.
Checked against 6 sources on 12 October 2026
Read the guide