Androgen receptor agonist; aromatized to estradiol.
Half-Life (t½)
IM: 192h
Dosing Guidelines
IM: Typical 100 (Range: 50–200)
Target Organ Systems
endocrine
Interactions
Testosterone enanthate (synergistic): Same active molecule, different ester length. Do not stack — pick one.
Gonadorelin (synergistic): Gonadorelin is commonly included in TRT protocols to prevent HPG-axis shutdown / testicular atrophy.
Anastrozole (synergistic): Off-label pairing to limit E2 rise from exogenous T. Over-suppression of E2 causes its own bone + CV issues — target mid-range, not floor.
Finasteride (synergistic): TRT + finasteride used off-label to blunt DHT-mediated scalp/prostate effects without sacrificing AR-driven benefits. [Gormley 1995]
Notes
Prescription only. TRT context. IM depot models slow first-order absorption (ka ≈ 0.04/hr) into a two-compartment system: distribution α ≈ 0.05/hr (~14h), terminal β ≈ 0.0036/hr (~190h half-life). Replaces the v0.5 1-comp slow-ka approximation. AR receptor-occupancy row removed (2026-06-28 audit): its ~1 nM value was free-testosterone’s affinity cited to a guideline with no verbatim Ki; steroid AR Kd/Ki have no abstract-verbatim source per AUTHORING_GAPS.