First Endurance OptygenHP is a safe and legal way to increase athlete endurance and performance. This formula is completely free of stimulants and has been proven to reduce cortisol levels and improve lactic threshold. Studies have shown OptygenHP to lower cortisol levels by 26 percent and increase time to lactate threshold by 42 percent. It maximizes oxygen utilization and VO2 Max while also optimizing ATP production. A dose of beta-alanine helps with power and strength while reducing fatigue. With reduction in recovery time and improvements in time until exhaustion, OptygenHP preserves muscle while burning fat, helping you become the best athlete you can be.