marriage help: How do i get my wife off of phentermine - Help.com

Get your wife to a doctor. Phentermine acts like amphetamine, “speed”, and is a Schedule 4 drug.

(C) Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule III.
Control measures are similar to Schedule III. Prescriptions for Schedule IV drugs may be refilled up to five times within a six month period.

Drugs on this schedule include:
Benzodiazepines, such as alprazolam (Xanax), chlordiazepoxide (Librium), diazepam (Valium), temazepam (Restoril) (Note that some states require specially coded prescriptions for temazepam), flunitrazepam (Rohypnol) (Note that Rohypnol is not used medically in the United States, and some states have placed it in Schedule I under state law.);
Zolpidem (sold in the U.S. as Ambien);
Dextropropoxyphene (Doloxene) and propoxyphene (sold in the U.S. as Darvocet);
Long-acting barbiturates such as phenobarbital;
Some partial agonist opioid analgesics, such as pentazocine (Talwin);
Phentermine;

First she has to want to quit. Next with your support talk to her doctor about stepping down her dosage and removing it from her life.

If she isn’t willing to quit, then there isn’t anything you can do to FORCE her to quit.