Red raspberry leaf tea is a uterine tonic. It helps co-ordinate the uterus and strengthen it for effective contractions. So for women with an irritable uterus (lots of unproductive contractions that do not change the cervix) it can actually help. I take RLT from 20 weeks onwards to help combat the irritability which leads to constant runs of horrible contractions.

I read yesterday when researching actual clinically evidenced effects that RLT has a moderate impact if at all on the duration of 1st stage of labour, but can shorten the 2nd stage.