Testosterone Replacement Therapy (TRT) is a medical treatment designed to restore testosterone levels in individuals experiencing hypogonadism, commonly known as low T. This condition is diagnosed when a person has consistently low serum testosterone levels combined with related symptoms like fatigue, low libido, or changes in body composition. Because testosterone is a controlled substance, its administration requires careful medical oversight, and dosing must be highly individualized. Attempting to determine a dosage without professional guidance can be ineffective or dangerous.
Understanding Volume Versus Active Dose
The question of “how many mL” is often misleading because the therapeutic dose is measured in milligrams (mg), not milliliters (mL). Milligrams represent the amount of the active medication, while milliliters indicate the volume of the carrier oil that delivers the dose. The relationship between these two measurements is determined by the concentration of the testosterone solution, which is printed on the vial.
Common concentrations for injectable testosterone, such as Cypionate or Enanthate, are typically 100 mg/mL or 200 mg/mL. This concentration is necessary for converting the prescribed milligram dose into the volume needed for injection. For example, if a patient is prescribed 100 mg per week using a 200 mg/mL concentration, they inject 0.5 mL. If the concentration is 100 mg/mL, the patient would need 1.0 mL. Therefore, the milliliter measurement is entirely dependent on the drug’s concentration, not the dose itself.
Typical Starting Ranges for Testosterone Replacement Therapy
The dosage for injectable TRT is always prescribed in milligrams (mg) per week. For adult males, the typical starting range for an injectable testosterone ester, such as Cypionate or Enanthate, is between 50 mg and 100 mg per week. This initial range is considered conservative, allowing the body to adjust while providers assess the initial response.
Some protocols utilize higher starting doses, sometimes ranging from 100 mg to 200 mg per week, or administer the higher amount every two weeks. Since common esters have a half-life of around eight days, weekly injections are often preferred to minimize hormone level fluctuation. The goal of this starting dosage is to bring the patient’s total testosterone levels into the mid-normal reference range, typically between 400 and 600 ng/dL.
Key Variables That Determine Your Weekly Dose
The appropriate final weekly dose is determined by a process of careful adjustment, or titration, based on several individual factors. A patient’s baseline laboratory results, specifically their total and free testosterone levels before treatment, are the primary focus. Individuals starting with severely low testosterone may require a slightly higher initial dose to reach the therapeutic range.
The patient’s reported symptoms, such as energy levels, mood, and libido, are equally important in guiding dose adjustments. A dose that normalizes blood levels but fails to resolve symptoms will likely be increased. Body mass index (BMI) and overall body composition also play a role, as higher body fat may convert more testosterone into estrogen. Age and individual metabolism affect how quickly the body processes and clears the hormone, influencing the final therapeutic range.
Injection Frequency and The Role of Medical Monitoring
While the traditional approach to TRT often involved injections every one to two weeks, many practitioners now prefer more frequent administration to maintain stable hormone levels. Injecting once or twice weekly helps to smooth out the peaks and troughs of testosterone concentration in the bloodstream. More stable levels are associated with a reduction in common side effects, such as mood swings and water retention, which occur when hormone levels fluctuate dramatically.
Ongoing medical monitoring is required for safe and effective TRT, involving regular laboratory work and symptom checks. Initially, blood work is performed a few months after starting therapy or changing the dose to ensure the medication achieves the target range. Once stable, monitoring typically continues every six to twelve months to check serum testosterone, estrogen, and hematocrit levels. These periodic checks confirm the dose remains appropriate and mitigate potential health risks, such as an excessive increase in red blood cell count.