Ah poor James - Harry is having a tough time too. I don't think they can build up immunity to calpol as I spoke to GP about it and she said you can use it for up to a week. I also think of it as if I was in so much pain, I'd want some painkillers too! I try not to use it unless he seems particularly bad, but sometimes I think it's not so bad to use medicine if they're really in pain. Personally I'm dubious about how much teething gels and powders do, but I know some people swear by them. Let's hope this difficult period passes soon xxx