Phentermine is an FDA-approved appetite suppressant used for the short-term management of exogenous obesity. This prescription-only medication functions as a central nervous system stimulant, reducing hunger and increasing feelings of fullness. It must be used temporarily alongside a comprehensive weight-loss plan, including reduced-calorie dieting, increased physical activity, and behavioral modifications.
Criteria for Phentermine Eligibility
A patient must demonstrate an initial body mass index (BMI) of 30 kg/m² or greater to qualify for phentermine. Individuals with a BMI of 27 kg/m² or greater can still qualify if they have at least one weight-related comorbidity. These associated conditions include controlled hypertension, type 2 diabetes, or dyslipidemia.
Patients must also have a documented history of failing to achieve weight loss goals through non-pharmacological methods alone, such as diet and exercise. Before any prescription is issued, a thorough medical history and physical examination are required to screen for contraindications.
Absolute contraindications include a history of cardiovascular disease, such as coronary artery disease, stroke, uncontrolled hypertension, or congestive heart failure. Patients with hyperthyroidism, glaucoma, or a history of drug abuse are also excluded from treatment. The medication is contraindicated during pregnancy and breastfeeding, as weight loss is not recommended for expectant mothers and the drug’s effects on a developing fetus are a serious concern.
Types of Prescribing Healthcare Providers
Primary Care Physicians (PCPs), including family practitioners and internal medicine doctors, manage general health and can prescribe phentermine as part of routine obesity care. Their familiarity with a patient’s overall health history makes them well-suited for the initial risk assessment.
Specialists often demonstrate greater comfort and expertise in prescribing anti-obesity medications. Bariatric Medicine Physicians, who are certified obesity specialists, regularly utilize phentermine and similar drugs as part of long-term weight management strategies. Endocrinologists also prescribe this medication, especially when obesity is linked to underlying hormonal or metabolic conditions like diabetes.
Nurse Practitioners (NPs) and Physician Assistants (PAs) also hold prescriptive authority for phentermine. Phentermine is classified as a Schedule IV controlled substance, which is within the prescribing scope of most mid-level practitioners. However, the specific regulations for NPs and PAs vary significantly by state, sometimes requiring a collaborative agreement with a supervising physician or placing limits on the duration of the prescription. All prescribers of controlled substances must hold a valid Drug Enforcement Administration (DEA) registration number.
Navigating the Prescription Process
The initial consultation includes a comprehensive physical exam, a review of cardiac health, and often requires baseline lab work to assess metabolic function. Prescribers must specifically check the patient’s blood pressure and heart rate, as phentermine can elevate both and pose a risk to cardiovascular health.
The medication is subject to strict regulatory oversight regarding its dispensing and monitoring. The FDA-approved use is limited to short-term treatment, typically interpreted as no more than 12 weeks. This temporary duration is intended to provide a jump-start to weight loss while minimizing the potential risks of long-term use.
Refills are managed under federal and state controlled substance laws, which typically permit a maximum of five refills within a six-month period. Many states impose additional restrictions, often limiting prescriptions to a 30-day supply and requiring a new medical evaluation for each refill. This mandatory follow-up schedule ensures the prescriber can continuously monitor for cardiovascular side effects, check for the development of tolerance, and document the patient’s progress. If a patient fails to lose a specified percentage of weight within the initial weeks, the prescriber will often discontinue the medication.
Finding a Qualified Prescriber
Searching for providers certified by the American Board of Obesity Medicine is a reliable strategy. These specialists have advanced training in the medical management of weight loss, including the use of pharmacotherapy. General practitioners remain a viable option, but patients should confirm their comfort level with anti-obesity medications during the scheduling process.
Telehealth services have expanded access, but the prescribing of phentermine online is highly regulated and varies by state. Because it is a controlled substance, many states require an in-person physical exam or the establishment of a prior in-person relationship before the initial prescription can be issued. Patients interested in telehealth should confirm that the service and the prescriber are licensed in their state and adhere to all local regulations.