In theory yes if it is overdone and if the body has defective feedback system and poor clearance, among other considerations. Like any nutrient, your body needs a certain amount.The key comes down to dosage to match the body's state of clearance, and that is why it is usually administered in graded fashion and titrated to match the body's tolerance. good question. One persons nutrient can be another person's toxin. Most normal people will not feel the difference. Then again , normal people don't get adrenal fatigue. Those in advance stage need to be more careful with any nutrient as a general statement. I have some that can tolerate a very big dose while some cannot tolerate even a drop.