Testosterone is the primary male sex hormone, produced mainly in the testes, regulating numerous physiological processes. It influences bone density, fat distribution, muscle mass, and red blood cell production. When a man experiences symptoms of low testosterone (hypogonadism), Testosterone Replacement Therapy (TRT) may be initiated. A dosage of 200 milligrams (mg) per week is often considered a high-end starting or maintenance dose, designed to restore serum levels to a healthy, mid-to-upper normal range.
Expected Physical and Mental Changes
The 200 mg weekly dose is designed to maximize positive effects, often targeting total testosterone levels between 600 and 1000 nanograms per deciliter (ng/dL). Physical changes primarily involve body composition, including increased lean muscle mass and reduced fat tissue. Elevated testosterone enhances protein synthesis, supporting muscle growth and recovery, especially when combined with resistance exercise.
Patients often report initial improvements in energy and vitality within the first three to six weeks. Over several months, anabolic effects lead to measurable increases in strength and physical performance. This dosage supports bone mineral density, protecting against age-related bone loss and fracture risk.
Mentally and emotionally, restoring balance can reduce chronic fatigue and improve mood. Testosterone regulates emotional well-being, enhancing focus, cognitive function, and general assertiveness. Enhanced libido and improved sexual function are common benefits, often noticed early in therapy.
Internal Physiological Markers Requiring Monitoring
The 200 mg weekly dosage necessitates careful medical monitoring of several internal physiological markers to ensure safety. A common effect is the stimulation of red blood cell production (erythrocytosis), monitored by checking hematocrit (the volume percentage of red blood cells) and hemoglobin levels. If hematocrit rises too high, the blood thickens, increasing the risk of cardiovascular events like stroke or blood clots. Regular blood work detects this change, allowing the clinician to adjust the dose or recommend therapeutic phlebotomy (blood donation).
Lipid profiles must also be monitored, as TRT can sometimes decrease high-density lipoprotein (HDL) cholesterol. For men over 40, monitoring the Prostate-Specific Antigen (PSA) level is standard practice before and during TRT. While testosterone does not cause prostate cancer, it can stimulate the growth of pre-existing cancer cells or cause a temporary increase in prostate volume. Monitoring PSA tracks significant changes that might warrant further urological investigation.
Managing Common Adverse Effects
The higher 200 mg weekly dose increases the probability of adverse effects, primarily due to the conversion of excess testosterone into estrogen (aromatization). Elevated Estradiol (E2) levels can lead to undesirable symptoms, including increased fluid retention (puffiness or bloating) and breast tissue sensitivity, which may progress to gynecomastia (breast enlargement). Emotional lability, or increased mood swings, can also signal high estrogen levels.
Providers manage these issues by prescribing an aromatase inhibitor medication to reduce E2 conversion, or by adjusting the testosterone dose. Splitting the weekly dose into smaller, more frequent injections can also stabilize hormone levels and reduce peak-related side effects.
Other common adverse effects are androgenic, stemming from elevated testosterone and its metabolite, dihydrotestosterone (DHT). These include increased oiliness of the skin and acne, particularly on the back and shoulders. Men predisposed to male pattern baldness may experience accelerated hair thinning or loss. Furthermore, exogenous testosterone suppresses the body’s natural hormone production, leading to testicular atrophy, which is an expected outcome of TRT.
Variability in Individual Response and Dose Titration
The 200 mg per week is a fixed numerical dose, but resulting hormone levels and clinical outcomes vary widely among individuals. A person’s unique metabolism, body fat percentage, and genetic factors influence how much testosterone is absorbed, metabolized, and converted into estrogen. For instance, individuals with a higher body fat percentage tend to have increased aromatization, potentially leading to more estrogen-related side effects.
The goal of TRT is not to hit a fixed dose, but to achieve a stable serum testosterone level within the therapeutic range that resolves symptoms without causing adverse effects. This requires consistent follow-up blood testing to measure both peak and trough hormone levels. Peak levels are measured shortly after injection, and trough levels are measured just before the next scheduled injection, providing a full picture of hormonal stability.
Many patients find that a lower dose, such as 150 mg or 100 mg per week, is sufficient to achieve optimal results and reduce side effects. The 200 mg dose is often a starting point that allows the clinician to gauge the patient’s individual response. The dose is then carefully titrated up or down based on symptoms and blood work to find the personalized, effective dosage.