Roughly half do, once more than one drug is involved. A pragmatic trial randomized 173 insured adults to an SGLT2 inhibitor, a GLP-1 drug, or both. They filled through their own insurance [1]. At four months, 84% assigned one drug had filled it. 53% assigned two had filled both, P < .001.
The fill step, measured
Almost every adherence figure comes from a trial that hands people the drug. This one did the opposite on purpose. Participants got a prescription and then met a pharmacy counter, like anybody else.
By the end of a ten-month median follow-up the figures were 87% and 68%. So about a third of people told to start two medications had not started both. That happened inside a trial, with staff actively helping. It is the same gap tracked from the other end in what prior authorization costs you.
Two limits apply. This is a feasibility phase with 173 participants, not the main trial, and it reports no clinical outcomes at all. Quality-of-life instruments showed no change over the period.
Who reaches the counter in the first place
A national survey covered 2,542 US adults with type 2 diabetes, representing about 30.3 million people [2]. Income above the median carried an adjusted odds ratio of 1.61 for using semaglutide, 95% CI 1.14 to 2.26. Private insurance carried 1.52, 95% CI 1.04 to 2.22.
Both intervals sit above one, so both associations are real in this sample. An odds ratio is not a percentage, and the study reports no rates to turn it into one. Racial and ethnic disparities were observed and did not reach significance after adjustment for income, insurance, education and employment.
Those data are from 2022. The cash-pay compounded market was barely a consumer phenomenon then, so this describes access under insurance rather than buying in 2026. Who the price filters out now is counted in who turns a prescription down.
Filling it once is not staying on it
A retrospective analysis followed 1,374 adults dispensed an initial GLP-1 [3]. 436 of them, 31.7%, discontinued inside 180 days. The documented reason was an adverse drug reaction in 26.8% of cases and a cost concern in 14.4%.
A weight indication rather than diabetes carried an adjusted odds ratio of 2.46 for stopping, 95% CI 1.17 to 5.17. That is the population most sellers on this roster serve. What it does to a prepaid term is worked out in the prepay arithmetic.
What this changes for a cash buyer
Every step between a prescription and a dose is a place the chain breaks. The counter, the price, the first side effect, the second refill. Insured people in a trial managed a two-drug regimen barely half the time at four months.
A self-pay buyer faces the same pharmacy and the same side effects without the insurance or the study coordinator. Price the regimen you will be taking in month six, not the one on the intake form. Start from what a GLP-1 actually costs per month and how long people stay on one.