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