well i'm not a doctor ,but i know that if i drink while i'm on my period, it's even more heavier than if i don't, it's heavy enough for me if i don't drink., but my mother-in-law had a partial hysterectomy b/c she bled too much and it was making her anemic. if your friend did get the mirena, it could help her bleeding to lighten or stop, she could also have some other serious problems from it, and since she's a drinker and smoker it could only make things worse. i hate to say it, but it might be best for her to maybe get a partial hysterectomy. if i were her, i would talk to my doctor and see what he/she has to say about that. just to let you know also that my mother -in-law is doing fine and glad she had it done. she was in her 40s too. hope this helps.