Almost every conversation about these medicines is about how well they work. This one is about how long people actually take them, and the answer is uncomfortable.
What happened
Researchers used United States commercial claims data from 2021 to 2023 to follow everyone aged 10 or over who started a GLP-1 for obesity without diabetes: 201,229 adults and 1,139 children and teenagers. They measured the proportion of days covered by a prescription, month by month, for a year, and then let the data sort itself into patterns rather than imposing one (PubMed 42755139).
Five distinct trajectories appeared among adults:
| Pattern | Share of adults |
|---|---|
| Immediate discontinuers | 19.6% |
| Early discontinuers | 23.5% |
| Late discontinuers | 20.7% |
| Intermittent | 5.5% |
| Persistent users | 30.7% |
Across those groups the average annual proportion of days covered ranged from 0.10 to 0.87. Among the paediatric patients the five groups were more evenly spread, each holding roughly a fifth of the cohort, with persistent users at 20.3%.
One other finding is hard to explain away. Where you live predicted whether you kept going. Adults in the Northeast had 1.32 times the odds of being persistent users compared with those in the South, and among children and teenagers the gap was wider still at 1.65.
What the number is and is not
A claims database sees prescriptions filled, not tablets swallowed or injections taken, so this measures supply rather than use. It also cannot see why anyone stopped. Cost, supply shortages, side effects, insurance changes, reaching a goal and deciding to stop are all folded into the same line.
That last point matters. Not every discontinuation is a failure. Some people stop on purpose, with a plan, having got what they came for.
But 19.6% stopping almost immediately is not that. That group filled a prescription and effectively never started, and a regional pattern that holds in both adults and children points at access and cost rather than at biology or willpower.
What it means for you
Two things worth taking from it.
The first four to eight weeks are the whole game. That is the dose escalation window, it is when nausea and constipation are at their worst, and it is when four people in ten in this study were already on their way out. If you are in it now, the symptoms are not a sign the medicine is wrong for you. They are the part that passes, and there is a great deal you can do about them with food.
And if you are going to stop, stop deliberately. Running out and drifting off is the worst version, because tolerance fades during a gap and going back to your old dose afterwards is reliably unpleasant. A planned stop, with your prescriber, is a different thing altogether.
What to do with this
Most of what makes the first two months bearable is what is on the plate: enough protein, fibre and fluid together, and portions small enough to finish. That is what the plan is for.