Why were trials carried out on human growth hormone before it was used in humans?

Trials on human growth hormone (hGH) were conducted before its use in humans to ensure safety and efficacy. Preclinical studies typically involved animal models to assess the hormone's biological effects, potential side effects, and optimal dosing. These trials aimed to gather critical data to inform clinical studies, minimize risks to human subjects, and comply with regulatory requirements. Ultimately, the goal was to establish a foundation of scientific evidence to support its therapeutic use in treating growth deficiencies and other medical conditions.