Types of TRT: Every Testosterone Delivery Method Compared

Why delivery method matters

Testosterone's biological effects depend on maintaining serum levels within a therapeutic range — roughly 500-900 ng/dL for most men on TRT, though optimal ranges are individual and should be determined with a physician. Delivery method determines:

• How quickly levels rise after administration
• How stable levels remain between doses
• Whether serum testosterone peaks high (supraphysiological) or stays flat
• Daily burden on the patient
• Transfer risk to partners or children
• Cost

No delivery method is universally superior. The clinical literature supports all of them as effective when appropriately dosed. Patient preference, lifestyle, and specific clinical context determine the right choice.

Intramuscular injections

Administration: Injected into the gluteus, vastus lateralis or deltoid. Weekly or biweekly are the most common schedules; some protocols use twice-weekly injections to smooth peaks.

Common formulations: Testosterone cypionate (most common in the US), testosterone enanthate. Both are long-acting esters that clear over 7-14 days.

Pharmacokinetics: Levels peak 24-72 hours post-injection and then decline. Weekly injections produce a wave pattern: above range shortly after injection, declining toward the lower end by day 7. Twice-weekly injections significantly reduce this fluctuation.

Clinical trade-offs

• Cost: lowest of all methods (generic cypionate is inexpensive)
• Stability: moderate (weekly) to good (twice-weekly)
• Adherence: requires willingness to self-inject
• Hematocrit: IM injections tend to raise hematocrit more than other methods due to the supraphysiological peaks — monitoring is essential

Best suited for: Patients comfortable with self-injection who want the most cost-effective protocol. The standard first-line approach in most US TRT practices.

Subcutaneous injections

Administration: Injected into abdominal subcutaneous fat using a short, fine needle — similar to insulin injection technique.

Common formulations: Same esters as IM (cypionate, enanthate), typically at lower doses (50-70mg twice weekly is common vs 100mg weekly IM).

Pharmacokinetics: Absorption is slower than IM, producing a flatter curve with lower peaks and more stable trough levels.

Clinical trade-offs

• Stability: better than IM for equivalent frequency
• Hematocrit impact: lower peak levels reduce hematocrit elevation compared to IM
• Comfort: smaller needle, less painful than IM for most patients
• Less commonly prescribed but increasingly preferred by men's health clinics for stability and tolerability

Best suited for: Patients who want injection-based TRT with more stable levels and lower hematocrit risk. The approach preferred by clinics like Marek Health and Hone for many patients.

Topical gels

Administration: Applied daily to shoulders, upper arms, or abdomen. Common brands: AndroGel (1% and 1.62%), Testim, Vogelxo, Fortesta.

Pharmacokinetics: Produces stable, relatively flat serum levels with daily application. No injection peaks. Absorption varies between individuals and application sites.

Clinical trade-offs

• Stability: excellent with daily application
• Transfer risk: meaningful risk of testosterone transfer to female partners and children through skin contact — requires care around application sites and timing
• Adherence: daily routine required
• Cost: higher than generic injectable cypionate; varies by brand and insurance

Best suited for: Patients who prefer not to inject and have low transfer risk in their household. Common starting method before transition to injections.

Transdermal patches

Administration: Applied once daily to back, abdomen, upper arm or thigh. Primary brand: Androderm.

Pharmacokinetics: Similar stability profile to gels with lower transfer risk due to contained delivery.

Clinical trade-offs

• Transfer risk: substantially lower than gels
• Skin irritation: more common than gels; the primary reason patients discontinue. Rotating sites reduces but does not eliminate this
• Stability: good
• Cost: generally higher than gels; less commonly prescribed

Best suited for: Patients who want transdermal delivery with minimal transfer risk and can tolerate potential skin irritation.

Testosterone pellets

Administration: Subcutaneous implantation, typically in the hip or buttock area. A minor in-office procedure performed every 3-6 months.

Common formulations: Testopel, various compounding pharmacy formulations.

Pharmacokinetics: The most stable delivery method available. Levels rise over the first 2-4 weeks post-implant, plateau, and then gradually decline as pellets are absorbed.

Clinical trade-offs

• Stability: highest of all methods
• Flexibility: none — dose cannot be adjusted after implantation. If dose is incorrect, you wait for the pellets to absorb (months)
• Procedure: minor outpatient procedure with small infection and extrusion risk
• Cost: typically not covered by insurance; one of the more expensive methods
• Monitoring: still requires periodic labs

Best suited for: Patients who strongly value set-it-and-forget-it delivery and dislike daily or weekly protocols. Popular in direct-pay men's health and longevity clinics.

Nasal gel

Administration: Applied inside the nostril three times daily. Brand: Natesto.

Pharmacokinetics: Rapid absorption produces peaks that clear within hours. Mimics a more natural diurnal testosterone pattern than other methods.

Clinical trade-offs

• LH/FSH preservation: uniquely, Natesto has been shown to maintain gonadotropin levels better than other TRT methods — relevant for men who want to preserve some testicular function and fertility
• Compliance: three-times-daily dosing is the highest burden of any method
• Stability: not as flat as gels or pellets
• Cost: higher; may not be covered

Best suited for: Men who specifically want TRT with better fertility preservation than standard methods, or who have clinical reasons to maintain some LH/FSH output.

Oral testosterone

Administration: Taken orally with food twice daily. Brand: Jatenzo (testosterone undecanoate).

Pharmacokinetics: Absorbed via the lymphatic system (avoiding first-pass liver metabolism). Produces moderate peaks post-dose.

Clinical trade-offs

• Convenience: no injection or skin application
• Blood pressure: Jatenzo carries an FDA black box warning for increased blood pressure — monitoring required
• Cost: high; less commonly prescribed than injectable or transdermal options
• Historical context: older oral testosterone formulations (17-alpha alkylated) were hepatotoxic. Jatenzo is not, but the historical association affects prescribing patterns

Best suited for: Patients who cannot inject and have skin contraindications to gels and patches, with close blood pressure monitoring.

Comparison summary

What to discuss with your physician

No delivery method should be chosen without a baseline lab panel and physician consultation. The choice depends on:

• Your baseline hematocrit (elevated baseline favors methods with flatter peaks)
• Transfer risk in your household (gels require care around children and female partners)
• Injection tolerance
• Cost and insurance coverage
• Fertility goals (nasal gel if relevant)
• Monitoring compliance (all methods require periodic labs)

For the baseline labs to run before starting any TRT method, see the pre-TRT lab guide. For provider comparisons (Hone, Marek, Maximus), see the TRT clinic comparison and the lab testing comparison.

Frequently asked questions