Which substance regulates the growth hormone levels in the body?

L-arginine is an amino acid that plays a significant role in the regulation of growth hormone levels in the body. Research indicates that L-arginine can stimulate the anterior pituitary gland to release growth hormone, particularly when it is administered in specific dosages. This is particularly relevant in scenarios where physical performance and recovery are considered, as higher growth hormone levels can support muscle growth, fat metabolism, and overall recovery.

In contrast, substances like caffeine and sibutramine do not have a direct influence on growth hormone secretion. Caffeine primarily acts as a stimulant and can increase alertness and energy, but it does not significantly impact hormone levels in the same way. Sibutramine, originally used as an anti-obesity medication, affects appetite regulation and does not play a role in the modulation of growth hormone secretion. Orlistat works by inhibiting fat absorption in the gastrointestinal tract and does not influence growth hormone levels either. Therefore, L-arginine stands out as the substance that effectively regulates growth hormone levels.