“NSDUH respondents who misused prescription pain relievers were asked to identify where they obtained the prescription pain relievers that they had most recently misused.7The most common source was “from a friend or relative for free” (50.5 percent; Figure 1).“

Excellent resource for those Kolodny disciples.

 

https://www.samhsa.gov/data/sites/default/files/report_2686/ShortReport-2686.html