DD is 16. She's has a rough few years with friendships and mental health issues but the last few months has improved immeasurably. She never used to go out but since she has been better is spending more time with friends- they're all at school with her and seem a nice enough bunch. However, now that DD is feeling much better she is going out with her friends to parties. We are relatively relaxed about alcohol and let her take a few drinks and to be fair she never seems to go over the top. She's been quite open with us that at some of these parties there are drugs- mostly weed I think though she mentioned one friend took MDMA- and that some of her friends have tried it. She says she doesn't do it but to be completely frank I don't believe her, I'm not sure why but I just have a feeling. We don't have any other issues with her, she does well at school and is working well for her GCSE's. She is going to another party tomorrow with a school friend- we know the family and they're a good bunch, but somehow something doesn't sit right with me. Am I being OTT? Is this just normal teenager experimentation?