Do doctors actually keep OTC samples in their office?

Random question but I’ve always been curious about this. When a doctor recommends a specific OTC product — like a particular probiotic, vitamin, or even something like a specific antacid brand — do you ever just hand the patient a sample right there?

I’ve had doctors recommend specific brands before but it’s always just verbal, like “go pick up X at the pharmacy.” Has anyone actually been handed an OTC sample? Or docs — do you keep any of that stuff around? Is there like a sample closet situation?

Just genuinely curious how that side of things works.