Testosterone therapy (T therapy) is a medical treatment used to increase circulating levels of the hormone. Individuals primarily seek this treatment for two distinct medical reasons: to address clinically low testosterone levels (hypogonadism) or as part of gender-affirming care for transmasculine people. This is a regulated medical procedure that begins with a thorough evaluation and continues with ongoing monitoring. Understanding the required steps, from establishing medical need to maintaining treatment, is the first step toward initiating therapy safely and effectively.
Determining Medical Necessity
The decision to begin testosterone therapy hinges on establishing a clear medical necessity, which varies depending on the individual’s health and goals. For cisgender men, the primary justification is the presence of hypogonadism, a condition diagnosed by both specific symptoms and consistently low laboratory values. Symptoms suggestive of low testosterone include persistent fatigue, a noticeable decrease in libido, changes in mood such as increased irritability or depression, and a reduction in muscle mass or strength.
A diagnosis of hypogonadism requires a confirmed low level of total serum testosterone on at least two separate occasions. Testing is typically measured in the morning before 10 a.m. while fasting. The threshold for a low level is generally considered to be below 300 nanograms per deciliter (ng/dL), though this can vary by laboratory reference ranges. Symptoms alone are not enough to justify treatment; they must correlate with confirmed low blood levels.
In the context of gender-affirming care, the medical justification follows a different set of criteria focused on the individual’s psychological well-being and gender identity. Guidelines from organizations like the World Professional Association for Transgender Health (WPATH) establish a standard of care for initiating masculinizing hormone therapy. These standards typically require a comprehensive assessment to confirm persistent gender incongruence and the capacity to consent to treatment.
Many healthcare providers now operate under an informed consent model, ensuring the patient understands the process, benefits, and risks of hormone therapy before starting. The goal of this therapy is to induce secondary sex characteristics that align with the patient’s gender identity, such as a deeper voice and changes in fat distribution. A thorough medical and mental health evaluation is required to ensure any co-existing conditions that might impact treatment are addressed.
The Initial Assessment and Required Testing
Once medical necessity is established, the next phase involves a comprehensive initial assessment and diagnostic laboratory testing. Finding an appropriate healthcare provider is the first step; this may be an endocrinologist, a urologist, or a primary care physician experienced in hormone management. The provider will conduct a physical examination and take a detailed medical history to identify any contraindications or existing health conditions.
The initial blood work establishes a baseline for hormone levels and overall health metrics. Fundamental tests include Total Testosterone and, sometimes, Free Testosterone, especially if the total level is borderline or if conditions like obesity affect sex hormone-binding globulin (SHBG). Free Testosterone measures the biologically active, unbound portion of the hormone available to tissues.
Additionally, Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) levels are measured to help determine the cause of the low testosterone. Elevated LH and FSH suggest a primary issue originating in the testes, while low or inappropriately normal levels point to a secondary cause in the pituitary gland or hypothalamus. The complete blood count (CBC) is also mandatory to measure baseline hematocrit and hemoglobin levels.
Monitoring hematocrit is important because testosterone therapy can increase red blood cell production, potentially leading to polycythemia and increasing the risk of blood clots. The baseline hematocrit should ideally be below 50%; a value above this may be a relative contraindication until the underlying cause is investigated. Other baseline tests often include Prostate-Specific Antigen (PSA) for men over 40, and metabolic parameters like a lipid profile and fasting glucose.
Understanding Delivery Methods
After an individual is cleared to begin treatment, a method of administration must be chosen, a decision often based on a balance of lifestyle, cost, and desired consistency of absorption. Testosterone is available in several forms, each with a unique pharmacokinetic profile. Injectable testosterone, typically testosterone cypionate or enanthate, is often the most cost-effective option and allows for precise dosing.
Injections can be administered intramuscularly or subcutaneously, usually every one to four weeks, but this schedule can lead to hormonal peaks shortly after the injection and troughs before the next dose. Transdermal methods, such as gels, creams, or patches, offer a more stable, steady absorption of the hormone throughout the day, closely mimicking the body’s natural circadian rhythm. However, gels and creams require daily application and carry a risk of accidental transfer to others through skin contact.
The transdermal patch maintains steady levels but may cause skin irritation or be less effective for higher doses. Subdermal pellets, which are implanted under the skin, provide the greatest convenience, releasing a consistent dose of testosterone over three to six months. This method involves a minor procedure for implantation and removal, but it offers less flexibility for immediate dosage adjustments compared to gels or injections.
Starting Treatment and Follow-Up Care
The process starts with the initial prescription, where the healthcare provider determines a starting dosage, often titrating low to allow the body to adjust. For individuals administering injections at home, proper self-administration technique is taught to ensure sterile and effective delivery. Adjustments are expected based on the body’s response and subsequent lab work.
Regular follow-up and monitoring are fundamental to safe and effective treatment, ensuring that hormone levels are within the target mid-to-upper normal range. The first follow-up appointment is typically scheduled within one to two months, with formal testosterone level testing occurring two to three months after initiation or after any dose change. For injectable formulations, blood should be drawn midway between injections to accurately assess the drug’s efficacy.
During the first year of therapy, follow-up visits and lab work are generally required every three to six months to monitor for potential side effects and confirm symptomatic improvement. The complete blood count, specifically hematocrit, is rechecked to detect polycythemia. If the hematocrit rises above 54%, the therapy may be temporarily stopped or the dosage reduced. After the first year, if the patient is stable, monitoring may transition to an annual schedule.