"Among persons aged 12 or older in 2010-2011 who used pain relievers nonmedically in the past year, 54.2 percent got the pain relievers they most recently used from a friend or relative for free (Figure 2.14). Another 12.2 percent bought them from a friend of relative (which was higher than the 9.9 percent in 2008-2009). In addition, 4.4 percent of these nonmedical users in 2010-2011 took pain relievers from a friend or relative without asking. More than one in six (18.1 percent) indicated that they got the drugs they most recently used through a prescription from one doctor. Less than 1 in 20 users (3.9 percent) got pain relievers from a drug dealer or other stranger, 1.9 percent got pain relievers from more than one doctor, and 0.3 percent bought them on the Internet. These other percentages were similar to those reported in 2008-2009."
Substance Abuse and Mental Health Services Administration, Results from the 2011 National
Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-44, HHS Publication No. (SMA) 12-4713. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012, p. 28.