Sources close to the "Mean Girls" actress said doctors at the rehabilitation facility determined she does not need the addictive drug to control attention deficit hyperactivity disorder.
Doctors rarely prescribe the drug to anyone over the age of 15 because there are numerous substitute medications that don't have the same addictive qualities, TMZ reported Saturday.
The sources said Lohan told her friends she can't stay at the Betty Ford Center and wants to move to another rehab facility that may not be so strict about her Adderall use.
Lohan checked into Betty Ford May 2 as part of a 90-day sentence for reckless driving. Lohan pleaded no contest to the charges in March and agreed to enter rehab, spend 18 months in psychotherapy and serve 30 days of community service.