Exercise caution when considering this supplement. I took 600 mg daily for four days, and on the fourth day, I ended up in the emergency room, fearing I was having a heart attack. I experienced excruciating chest and arm pain, dangerously low blood pressure (74/46), cold sweats, and nausea. I called 911 and was rushed to the ER, where all tests ultimately came back negative for a heart attack. After conducting some thorough research, I identified the cause as a severe reaction to NAC. Investigate the symptoms I encountered, and you'll understand the potential dangers associated with this supplement.