Ah yes, the cold. That's the only side effect I've had so far, thank God. It is horrible though, I'm freezing in work everyday and have to sit in a chunky cardi, fleece and scarf. And I'm constantly covered in a blanket at home, even had to take it with me to a friends house last night as I knew if be freezing. Still, it's worth it. And at least it's not winter!