@kathleen1314 I agree that her reaction and mine may not be the same. I do know that I hesitated to take the strontium . I finally started due to good reviews and within 2 days, I had hives. Coincidence? Maybe, but I had taken nothing different than my regular vitamins. I have never had hives before, so I still feel that strontium caused my reaction . It is starting to subside after 3 days without taking the strontium again. Algae Cal was quick to refund me when I contactd them. Just cautioning others.