… Then I cam across some people reporting palpitations or racing heart from whey protein. The light bulb went off, I had just started a new protein powder that I take before workouts. I was using the same protein for years, but GNC dropped the old SKU and reformulated it. It seemed to line up to the time I noticed the palpitations. So I stopped the protein and within a day I have had maybe 1 palpitation that I noticed in the last 5 days. My EKG has been clean and I check it all the time. Wish they would regulate all the damn vitamins and supplements.