Dr. Drew Pinsky is "very concerned" about Brooke Mueller's plans to go to Mexico for an addiction program that isn't approved in the U.S., in an exclusive interview.

Mueller has suffered another setback in her ongoing battle with her addiction to drugs, specifically, methamphetamines, and she is going to be taking an extreme measure to attempt to get sober. Mueller plans to go to Mexico and enter a facility that will give her ibogaine, which is supposed to stop the cravings for drugs. Ibogaine isn't legal in the U.S.

"In my experience people, after ibogaine, stop opiates for three to six months and then they begin again," Dr. Pinsky

"I have had this experience with dozens of patients, but most disturbingly these patients had persistent mood and personality changes."

Many U.S. medical experts concur about the dangers associated with ibogaine and the hallucinogen is classified as a Controlled Substance in the U.S. Ibogaine is approved in other countries, however, including Mexico, Canada, and elsewhere for the treatment of drug addicts

Mueller recently finished a 45-day outpatient rehab stint, but relapsed within days.