I think its the CEE thats causing it but I started taking it along with 2 other suppliments: I take in roughly 180g of protein in various forms and drink about 6 liters (1.5 gallons) of water throughout the whole day. The muscles that are affected are usually the muscles that i worked out either the previous day or the day before that. Is this a common issue with cee? I did not expereience this when i was taking monohydrate. I'm still going to take the cee either way because it is only a minor annoyance.