I had a SEVERE Allergic reaction to the TNS Essential Serum that sent me to the hospital twice in 38 hours. First developed itchy, painful, raised welts accompanied by sores on the inside of my nose & mouth with such severe swelling my right eye was swollen shut. My mouth hurts so bad I have not been able to eat for 5 days. Then developed SEVERE eye, ear & jaw pain that was unbearable. Was placed on steroids the first 24 hours followed by heavy duty antibiotics with the 2nd trip to the ER. I NEVER have allergies to anything. Missed entire week of work. Not worth it. I purchased this off Ebay but sure it was is a genuine product.