TRT is not one treatment. It's a family of delivery mechanisms that all accomplish the same goal — raising serum testosterone to a physiological range — but through different pharmacokinetic profiles, administration routes, and practical requirements.
Most men start with injectable testosterone cypionate. It's the cheapest, the most adjustable, and the most studied. From there, you can switch based on preference. The comparison below covers what each method actually entails.
Delivery Method Comparison
Testosterone Cypionate (Injection)
The most common TRT form in the US. Testosterone cypionate has a half-life of approximately 8 days, making weekly or twice-weekly injections standard. Administered intramuscularly into the glute, quad, or deltoid — or subcutaneously in smaller doses. Most patients self-administer at home after a brief instruction. Levels peak 24–48 hours post-injection and trough before the next dose; twice-weekly dosing reduces peak-to-trough fluctuation.
Advantages
Lowest cost. Predictable pharmacokinetics. Easy to adjust dose quickly.
Considerations
Requires injections. Some men experience mood variation with level fluctuation.
Testosterone Enanthate (Injection)
Nearly identical to cypionate in clinical effect. Enanthate has a slightly longer half-life (approximately 10–11 days) but the practical difference at standard weekly dosing is minimal. Often used when cypionate is unavailable from a specific pharmacy, or based on physician preference. Same self-injection protocol as cypionate.
Advantages
Slightly longer half-life than cypionate. Interchangeable in most protocols.
Considerations
Same injection frequency required as cypionate for optimal level stability.
Testosterone Undecanoate (Aveed)
A long-acting injectable testosterone (brand name Aveed) with a 10-week dosing interval. The extended release is achieved through a castor oil vehicle. Due to risk of pulmonary oil microembolism, FDA requires it be administered in a physician office with a 30-minute observation period post-injection. Not suitable for home administration. Typically more expensive than compounded options.
Advantages
Very infrequent dosing. Good for patients who cannot or will not self-inject.
Considerations
Requires clinic visit every 10 weeks. Cannot adjust dose easily. Higher cost.
Transdermal Testosterone Gel (AndroGel, Testim, compounded)
Applied once daily to the shoulders, upper arms, or inner thighs. Avoids injection entirely and produces relatively stable testosterone levels without the peak-trough pattern of weekly injections. Transfer risk to partners and children is the primary safety concern — gel must dry fully and contact with application sites avoided. Compounded testosterone cream is similar; some patients prefer cream formulations for easier application.
Advantages
No injections. Stable daily levels. Good option for needle-averse patients.
Considerations
Transfer risk. Daily application required. Slightly higher cost than injectable.
Testosterone Pellets (subcutaneous implant)
Small pellets (roughly the size of a grain of rice) are inserted subdermally, typically in the upper buttock or hip, under local anesthesia. The procedure takes about 10 minutes in a physician office. Pellets dissolve slowly, releasing testosterone over 3–6 months. Level stability is generally excellent after the initial loading period. Dose adjustment is not possible once inserted — if levels are too high or a side effect emerges, you must wait for the pellets to dissolve.
Advantages
Maximum convenience once inserted. Stable levels. No daily or weekly tasks.
Considerations
In-office insertion required each cycle. Cannot adjust or remove quickly. Higher cost per cycle.
Target Range and What the Numbers Mean
The standard lab reference range for adult male total testosterone is 300–1,000 ng/dL. That range is wide and was constructed from population data — not from what levels produce optimal function in a given individual.
Most TRT protocols target 700–1,000 ng/dL. Some physicians prefer 800–900 ng/dL as a steady-state target: high enough for full symptom resolution without pushing hematocrit or driving excessive estradiol conversion. Free testosterone matters too — men with high SHBG can have adequate total testosterone but low free testosterone, the fraction that actually enters cells.
Total Testosterone Target
700–1,000 ng/dL
Measured at trough (before next dose)
Estradiol Target
20–40 pg/mL
Some physicians allow up to 50 pg/mL if asymptomatic
Hematocrit Ceiling
< 52–54%
Protocol adjustment or phlebotomy if exceeded
Estrogen Management on TRT
Testosterone aromatizes to estradiol. Higher doses, higher body fat, and individual enzyme activity all affect how much conversion occurs. Estradiol is not the enemy — men need some estrogen for bone density, cardiovascular health, and libido. The problem is excess.
Symptoms of elevated estradiol on TRT: water retention, nipple sensitivity, emotional lability, reduced libido despite good testosterone levels. Lab confirmation (estradiol above 40–50 pg/mL) before adding an aromatase inhibitor is standard practice.
Anastrozole (0.25–0.5mg twice weekly) or exemestane are the most common AIs used in TRT protocols. Many men never need one. Your physician determines whether AI is appropriate based on your lab values and symptoms — not as a prophylactic default.
Monitoring Schedule
Baseline
Total testosterone (AM draw), free testosterone, SHBG, estradiol, LH, FSH, hematocrit/CBC, PSA (men 40+), metabolic panel. Establishes your pre-treatment baseline.
6–8 weeks post-start
Total testosterone (at trough), free testosterone, estradiol, hematocrit. Confirms your protocol is achieving target range. Adjustments made here if needed.
Every 3–6 months (stable)
Full panel repeated. Includes testosterone, estradiol, hematocrit, PSA. Most patients see their physician by telehealth for these check-ins.