"• Among persons aged 12 or older in 2011-2012 who used pain relievers nonmedically in the past year, 54.0 percent got the pain relievers they most recently used from a friend or relative for free (Figure 2.16). Nearly 1 in 5 (19.7 percent) received them through a prescription from one doctor (which was higher than the 17.3 percent in 2009-2010). Another 10.9 percent bought them from a friend or relative. In addition, 4.0 percent of these nonmedical users in 2011-2012 took pain relievers from a friend or relative without asking. An annual average of 4.3 percent got pain relievers from a drug dealer or other stranger; 1.8 percent got pain relievers from more than one doctor; 0.8 percent stole pain relievers from a doctor's office, clinic, hospital, or pharmacy (which was higher than the 0.2 percent in 2009-2010); and 0.2 percent bought the pain relievers on the Internet.
"• Among persons aged 12 or older in 2011-2012 who used pain relievers nonmedically in the past year and indicated that they most recently obtained the drugs from a friend or relative for free, 82.2 percent of the friends or relatives obtained the drugs from just one doctor (Figure 2.16). About 1 in 20 of these past year nonmedical users of pain relievers (5.4 percent) reported that the friend or relative got the pain relievers from another friend or relative for free, 4.1 percent reported that the friend or relative bought the pain relievers from a friend or relative, 1.4 percent reported that the friend or relative bought the pain relievers from a drug dealer or other stranger (which was lower than the 2.3 percent in 2009-2010), 1.3 percent reported that the friend or relative took the pain relievers from another friend or relative without asking, and 0.2 percent reported that the friend or relative bought the pain relievers on the Internet."

Source

Substance Abuse and Mental Health Services Administration, Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-46, HHS Publication No. (SMA) 13-4795. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, pp. 29-30.
http://www.samhsa.gov/data/NS…
http://www.samhsa.gov/data/NS…