A Primary Care Physician (PCP) serves as the first point of contact for routine medical care, managing general health and coordinating specialized treatments. When patients present with symptoms suggesting low testosterone, or hypogonadism, they often look to their PCP to initiate diagnosis and treatment. Testosterone Replacement Therapy (TRT) is a common medical intervention used to restore hormone levels and alleviate symptoms like low libido, fatigue, and decreased muscle mass. The central question for many patients is whether their general practitioner has the authority and expertise to start this specialized treatment.
Scope of Primary Care Prescribing Authority
The short answer is that a Primary Care Physician generally has the legal authority to prescribe testosterone for a diagnosed medical condition. This ability is governed by federal regulation and can be limited by institutional policy. Testosterone is classified under the federal Controlled Substances Act as a Schedule III drug because it is an anabolic steroid that has an accepted medical use but carries a potential for abuse. This classification imposes specific requirements, such as prescriptions commonly expiring after six months with a maximum of five refills allowed. State laws or individual health insurance plans may also restrict the supply to a 30-day or 90-day maximum upon a single filling.
Although legally permitted to prescribe, some large hospital systems or clinics may internally limit TRT initiation to specialists. This institutional caution often stems from the complexity of diagnosing true hypogonadism and the need for long-term monitoring of potential side effects. The PCP must possess a Drug Enforcement Administration (DEA) registration number to prescribe any controlled substance, including testosterone.
Diagnostic Testing Requirements
Before a PCP can prescribe testosterone, they must establish a formal diagnosis of hypogonadism, requiring both clinical symptoms and laboratory confirmation. The diagnosis is not based on symptoms alone, as conditions like depression, sleep apnea, or obesity can mimic the signs of low testosterone.
The initial and most critical laboratory test is a measurement of the serum Total Testosterone level. This test must be drawn early in the morning, typically between 8:00 AM and 10:00 AM, because testosterone levels naturally peak at this time. If the result is below the standard threshold (often below 300 ng/dL), the test must be repeated on a separate day for confirmation.
To understand the cause of the low levels, the PCP will order additional hormone tests. These include Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH), which help distinguish between primary (testicular failure) and secondary (pituitary or hypothalamic issue) hypogonadism. A Prolactin level may also be checked, especially in cases of secondary hypogonadism, to screen for a pituitary tumor.
The PCP must also establish baseline measurements of other health markers before starting treatment. These mandatory checks include Prostate-Specific Antigen (PSA) for men over a certain age and Hematocrit, which measures the proportion of red blood cells in the blood. Monitoring the hematocrit is crucial because TRT can cause erythrocytosis, an increase in red blood cell count that raises the risk of blood clots.
Determining When a Referral is Needed
While a PCP can manage straightforward cases of hypogonadism, certain complexities necessitate a referral to a specialist, such as an endocrinologist or a urologist.
An endocrinologist specializes in the endocrine system and hormonal axes, making them the preferred specialist for diagnosing the root cause of secondary hypogonadism, which involves issues with the pituitary or hypothalamus. They are experts at interpreting complex hormone panels and ruling out underlying systemic illnesses contributing to low testosterone.
A urologist, who specializes in the male reproductive and urinary systems, is often required if the patient has specific structural or fertility concerns. Since TRT suppresses the body’s natural sperm production, any patient wishing to preserve fertility should be referred to a urologist before treatment begins. Urologists also manage complications related to the male anatomy, such as prostate issues or testicular pathology.
Referral is also warranted if the initial baseline labs are atypical or extremely low, or if the patient develops complex side effects during treatment. For instance, if the patient experiences persistent prostate concerns or a significant, unmanageable rise in their hematocrit level, the PCP should hand off management to a specialist.