Substance P, Free Acid, plays a significant role in various physiological processes, particularly in the nervous system. It is widely used in research to study its involvement in pain transmission and inflammation. By acting as a neurotransmitter and neuromodulator, it helps researchers understand mechanisms of chronic pain conditions and develop potential therapeutic interventions. Additionally, it is utilized in studies focusing on the gastrointestinal system, where it influences motility and secretion. In the field of immunology, Substance P is investigated for its role in mediating immune responses and its potential connection to inflammatory diseases. Its applications also extend to dermatology, where it is studied for its effects on skin conditions and wound healing. Overall, it serves as a valuable tool in biomedical research to explore its multifaceted biological functions.