When young men eat way less food than usual, giving them a high dose of testosterone makes some muscle-building signals in their cells stronger, but it doesn’t stop their muscles from breaking down — just like in guys who get a fake pill.

A randomized, double-blind, placebo-controlled trial in healthy young men (18–30 years) undergoing a 4-week severe caloric deficit (≤1000 kcal/day below maintenance), with one group receiving 200 mg/week intramuscular testosterone enanthate and the other receiving placebo. Primary outcomes: muscle protein synthesis rates via stable isotope tracer methodology; secondary outcomes: androgen receptor protein content and translational capacity (e.g., ribosome biogenesis, eIF4F complex assembly) in muscle biopsies collected at baseline and week 4.

A within-subject crossover trial in young men where each participant undergoes two 4-week severe caloric deficit phases separated by a 4-week washout: one with 200 mg/week testosterone and one with placebo, in random order. Muscle biopsies and muscle protein synthesis rates are measured at the end of each phase to compare molecular anabolic signaling and synthesis rates within individuals.

A small pilot study in young men on severe caloric deficit testing three testosterone doses (0, 100, 200 mg/week) over 3 weeks, with serial muscle biopsies to map dose-dependent changes in androgen receptor content, translational machinery markers, and muscle protein synthesis rates to determine if 200 mg/week is necessary for the observed molecular effects without functional recovery.

An observational cohort of young men voluntarily entering severe caloric deficit (e.g., competitive bodybuilders) who self-administer testosterone (200 mg/week) or not, with muscle biopsies and protein synthesis measurements taken at baseline and after 4–6 weeks, to assess real-world patterns of molecular signaling and functional outcomes without experimental control.

Human myotubes derived from young male donors cultured under nutrient-deprived conditions and treated with supraphysiological testosterone (200 ng/mL equivalent) to assess changes in androgen receptor expression and translational capacity (e.g., phosphorylation of 4E-BP1, S6K1) compared to vehicle control, while measuring protein synthesis rates via puromycin incorporation.