As we age, the amount of hormone secreted declines. By age 40, adults produce half of the growth hormone they did as 20-year-olds. By age 60, levels are one-third of what they once were. These declining levels contribute to typical signs of aging such as reduced muscle mass and strength, increased abdominal fat, reduced vitality and energy, poor general health, mood changes, insomnia, and unhealthy-looking skin. The therapeutic use of peptides to upregulate hormone production helps address various health and performance goals.