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Why is phentermine a controlled substance?

Medically reviewed by Carmen Pope, BPharm. Last updated on July 18, 2025.

Official Answer by Drugs.com

Phentermine is classified as a Schedule IV controlled substance by the DEA because it is a prescription stimulant medication with potential for abuse and dependence, though the risk is considered relatively low compared to other controlled substances.

Phentermine is a sympathomimetic amine that increases brain neurotransmitters (norepinephrine, dopamine, serotonin), creating abuse potential through appetite suppression for weight loss, increased energy and alertness, mood elevation with temporary euphoria, enhanced focus, and insomnia from stimulation. These effects are similar to amphetamines, and effects that drug misusers may seek.

Other Schedule IV controlled substances include benzodiazepines such as lorazepam and clonazepam; sleep medications such as zolpidem (Ambien) and eszopiclone (Lunesta); and tramadol.

Key Reasons for Phentermine's Controlled Status:

Related questions

What are the DEA Prescription Rules for Phentermine?

The rules set by the DEA for all Schedule IV controlled substances, such as phentermine are:

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