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The medicines

The GLP-1 medicines, explained

The medicines everyone calls "GLP-1s" are a family of six in regular use in the US, sold under more brand names than there are molecules. This site uses the generic names throughout. Here is what each one is, how it is taken, and how long it lasts.

By the Cafeity teamUpdated 4 min read

The short answer

GLP-1 receptor agonists mimic a gut hormone, GLP-1, that regulates appetite and blood sugar. The main ones in the US are semaglutide (weekly injection or daily tablet), tirzepatide (weekly injection; it also acts on the GIP receptor), liraglutide (daily injection), dulaglutide (weekly injection), exenatide (twice-daily injection) and orforglipron (a daily tablet approved in 2026).123456 They differ mainly in how often they are taken — which follows from their half-lives, from about 2.4 hours for exenatide to about a week for semaglutide — and in what they are approved for.

Line chart of how a single dose declines over 14 days for four GLP-1 medicines, from their label half-lives: semaglutide falls to about 25% after two weeks and tirzepatide to about 14%, while orforglipron falls to about 5% after one week and liraglutide to under 10% within two days.
One dose of each, from the published half-lives. The half-life is why semaglutide and tirzepatide are weekly, liraglutide and orforglipron daily.

What a GLP-1 medicine is

GLP-1 (glucagon-like peptide-1) is a hormone released by the gut after eating. It helps regulate blood sugar and appetite; the prescribing information notes the GLP-1 receptor is found in several brain areas involved in appetite regulation.1 GLP-1 receptor agonists are medicines that act on that receptor, but last far longer than the body's own hormone, which is broken down in minutes. Tirzepatide also acts on a second receptor, for a related hormone called GIP.2

The six, side by side

From each medicine's current US prescribing information. "Approved for" is summarised; check the label for exact indications.
MedicineHow it is takenHalf-lifeApproved for (US)
SemaglutideWeekly injection, or daily tabletAbout 1 weekWeight management; type 2 diabetes; lowering cardiovascular risk; kidney protection in type 2 diabetes; a liver condition (MASH)
TirzepatideWeekly injectionAbout 5–6 daysWeight management; obstructive sleep apnoea with obesity; type 2 diabetes; lowering cardiovascular risk in type 2 diabetes
LiraglutideDaily injectionAbout 13 hoursWeight management; type 2 diabetes; lowering cardiovascular risk in type 2 diabetes
DulaglutideWeekly injectionAbout 5 daysType 2 diabetes; lowering cardiovascular risk in type 2 diabetes
ExenatideTwice-daily injectionAbout 2.4 hoursType 2 diabetes
OrforglipronDaily tabletAbout 29–49 hoursWeight management

Sources: prescribing information.172839456

Why this site uses generic names

Each of these molecules is sold under one or more brand names, and some share a molecule across several products at different strengths. Cafeity uses the generic (international) name everywhere, which keeps an independent tool clearly separate from the manufacturers — and avoids the confusion of treating two brands of the same molecule as different medicines. Your prescription and your medicine's leaflet will show both.

What they have in common

  • Side effects are mostly gastrointestinal — nausea, diarrhoea, vomiting, constipation — and most common while the dose is being increased.12 See side effects.
  • Shared warnings — pancreatitis, gallbladder disease, dehydration and kidney injury, serious allergic reactions, and the risk of stomach contents entering the lungs during anaesthesia or deep sedation.126
  • A boxed warning about thyroid C-cell tumours, based on findings in rodents with this class of medicine, on every label here except twice-daily exenatide. They are not for people with a personal or family history of medullary thyroid carcinoma or MEN 2.165
  • Stepped doses, started low and increased by the prescriber.

Newer and investigational medicines

Several related medicines are in development, some combining GLP-1 with other hormone targets. Until a medicine is approved, its trial results are not a guide to treatment, and Cafeity does not write guides about unapproved products. Orforglipron, approved in 2026, is the newest member of the class and the only one that is a small non-peptide molecule rather than a peptide; see the orforglipron tracker.6

Common questions

What are the GLP-1 medicines?
The main ones in the US are semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide and orforglipron.123456
Is tirzepatide a GLP-1?
Yes, and more: it acts on both the GLP-1 and GIP receptors.2
Which GLP-1 is a pill?
Semaglutide is available as a daily tablet as well as an injection, and orforglipron is a daily tablet.16

Sources

  1. Semaglutide injection and tablets for weight management — US prescribing information DailyMed, US National Library of Medicine, version published 30 June 2026
  2. Tirzepatide injection for weight management and obstructive sleep apnoea — US prescribing information DailyMed, US National Library of Medicine, version published 2 September 2026
  3. Liraglutide 3 mg injection for weight management — US prescribing information DailyMed, US National Library of Medicine, version published 15 June 2026
  4. Dulaglutide injection — US prescribing information DailyMed, US National Library of Medicine, version published 10 August 2026
  5. Exenatide twice-daily injection — US prescribing information DailyMed, US National Library of Medicine, version published 8 September 2025
  6. Orforglipron tablets for weight management — US prescribing information DailyMed, US National Library of Medicine, version published 13 August 2026
  7. Semaglutide injection for type 2 diabetes — US prescribing information DailyMed, US National Library of Medicine, version published 10 June 2026
  8. Tirzepatide injection for type 2 diabetes — US prescribing information DailyMed, US National Library of Medicine, version published 2 September 2026
  9. Liraglutide injection for type 2 diabetes — US prescribing information DailyMed, US National Library of Medicine, version published 17 November 2025

Written by the Cafeity team from the sources listed here. Figures from prescribing information are quoted as the label states them; trial results are averages from those trials, not predictions for any one person. This page has not yet been reviewed by a clinician — see the editorial policy for how pages are researched and corrected.