Phentermine Drug Class: Is It A Controlled Substance?

Phentermine is a type of diet pill for helping people who have an unhealthy body weight or body mass index (BMI) to lose weight. It is considered an anorexiant. Brand names for phentermine include Adipex-P, Ionamin, Lomaira, Suprenza, and Fastin. Phentermine hydrochloride is sometimes used in combination with another drug called topiramate. A major brand name for this combination of phentermine-topiramate is Qsymia.

Like most prescription weight-loss pills, phentermine is not meant for someone who is looking to lose a few pounds. This drug is meant for people with obesity and for whom other methods of weight loss have not been successful. Phentermine shares many characteristics with stimulants and is considered a controlled substance by the United States Drug Enforcement Administration (DEA). It is currently listed as a Schedule IV drug.

Why Phentermine Is A Schedule IV Controlled Substance

A Schedule IV controlled substance is one that is considered to have a low risk for abuse and dependence. Drugs that are listed as Schedule IV also generally possess medical uses and value. Drugs that are Schedule IV, however, are still considered addictive on some level and can also be dangerous when combined with other drugs or when used alone in high doses.

What Drug Classification Is Phentermine?

Phentermine is part of the drug class called anorectics. This type of drug has a stimulant effect on the brain and works as an appetite suppressant. Not surprisingly, it is usually found in weight-loss medications.

Important contraindications to be aware of include:

• glaucoma
• history of cardiovascular disease, heart disease, or heart failure
• hyperthyroidism
• history of drug abuse
• recent use of any monoamine oxidase inhibitors (MAOIs)
• pulmonary hypertension

This type of drug can be dangerous, and it is important to be aware of any drug interactions or contraindications for use, according to the United States Food and Drug Administration (FDA).

How Phentermine Works When Ingested

Phentermine helps to suppress a person’s appetite by raising the levels of three of the body’s major neurotransmitters: serotonin, dopamine, and norepinephrine. As the level of these chemicals rise in the central nervous system, a person’s level of hunger decreases.

Weight-loss medications like phentermine work best alongside other weight-loss methods such as exercise and a reduced-calorie diet. These lifestyle changes are important, as phentermine is only meant to be taken in the short term.

Short-Term Side Effects Of Phentermine Use

Phentermine has stimulant-like qualities and can produce similar side effects, as it is also known to work the heart and cardiovascular system extra hard.

The following are some common side effects that can occur with phentermine use:

• constipation
• dry mouth
• diarrhea
• vomiting
• high blood pressure
• dizziness
• chest pain
• heart palpitations

What Happens When You Abuse Phentermine

Serious side effects are possible if someone does not follow the instructions of their healthcare provider and abuses phentermine in high concentrations. Health risks of phentermine abuse include skin lesions, irritability, insomnia, shortness of breath, psychosis, psychological dependence, heart disease, and increased risk for heart attack and stroke.

Is Addiction To Phentermine Possible?

While phentermine is classified as a Schedule IV controlled substance with relatively low abuse risk, addiction is still possible with long-term use. Phentermine works similarly to stimulants by increasing dopamine and norepinephrine in the brain, and can create feelings of euphoria, increased energy, and confidence that some people find appealing beyond weight loss. Over time, the body can develop tolerance, meaning higher doses are needed to achieve the same effects, increasing the risk of dependence.

Signs of phentermine addiction include taking higher doses than prescribed, using it longer than recommended, feeling unable to function without it, experiencing cravings, and continuing use despite negative consequences. People may engage in doctor shopping for multiple prescriptions or purchase phentermine illegally online. Suddenly stopping after prolonged use can trigger withdrawal symptoms including extreme fatigue, depression, increased appetite, and intense cravings, indicating physical dependence has developed.

Treatment Options For Phentermine Addiction

Overcoming phentermine addiction requires professional help and a comprehensive treatment approach.

Here are the main treatment options available:

• Medical Detox Programs: Supervised withdrawal in a medical facility where healthcare professionals monitor symptoms, provide medications to ease discomfort, and ensure safety during the detox process as phentermine leaves the system.
• Residential Treatment: Living at a treatment facility for 30 to 90 days, receiving 24-hour care, intensive therapy, and a structured environment free from access to phentermine and other substances.
• Outpatient Treatment Programs: Attending therapy sessions and counseling several times per week while living at home, allowing people to maintain work and family responsibilities during recovery.
• Cognitive Behavioral Therapy (CBT): A proven therapy approach that helps identify triggers, change negative thought patterns around food and body image, and develop healthy coping skills to resist cravings.
• Individual Counseling: One-on-one therapy sessions to address underlying issues like body image problems, eating disorders, or mental health conditions that may have contributed to phentermine misuse.
• Group Therapy: Peer support through group counseling sessions where people share experiences and support each other’s recovery from stimulant addiction.
• Dual Diagnosis Treatment: Specialized care for people with both phentermine addiction and co-occurring conditions like eating disorders, anxiety, depression, or other mental health issues.
• Nutritional Counseling and Weight Management: Working with nutritionists and health professionals to develop healthy eating habits and sustainable weight management strategies without relying on diet pills.
• Aftercare and Relapse Prevention: Ongoing support through counseling, support groups, and check-ins after completing primary treatment to maintain sobriety and prevent relapse.

Recovery from phentermine addiction is possible with the right treatment and support. If you or a loved one is facing drug or alcohol abuse, reach out to a treatment provider or SAMHSA for help finding care.

Written by the Addiction Resource Editorial Staff