Research

Hormonal

Testosterone administration stimulates net muscle protein synthesis without increasing inward amino acid transport, primarily by enhancing the reutilization of intracellular amino acids derived from protein breakdown.

Testosterone boosts muscle growth by making your body better at recycling amino acids from broken-down muscle protein back into new muscle, rather than by pulling more amino acids from your blood. This means that even without increased nutrient transport, your muscles can build more protein if testosterone levels are elevated.

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Thus T administration leads to an increased net protein synthesis and reutilization of intracellular amino acids in skeletal muscle.
Arny A. Ferrando et al. · American Journal of Physiology-Endocrinology and Metabolism · 1998

Why this rating

Randomized controlled trial with direct measurement of protein kinetics using stable isotopes and biopsies in healthy men.

Source

Testosterone injection stimulates net protein synthesis but not tissue amino acid transport

Arny A. Ferrando et al. · American Journal of Physiology-Endocrinology and Metabolism · 1998

DOI 10.1152/ajpendo.1998.275.5.e864

crossover · n=7Cited 252×
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DOI resolved against Crossref · corpus check 2026-06-10

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