Human Growth Factors and IGF-1 Precursors. Improves Physical Performance. Speeds Recovery. Enhances Cardiac Output Developed by leading research scientists & biochemist, Secretagogue-One™ addresses issues of vital importance for health, wellness & physical performance. Secretagogue-One™ is a proprietary blend of amino acids & precursor nutrients which enhance the body s natural production of Human Growth Factors & Insulin-like Growth Factor-1 . Increased Human Growth Factors & IGF-1 levels have been shown to improve physical performance, speed recovery from training, increase cardiac output, & increase immune f.