I just happened to be reading the ingredient list to my favorite brand of bedtime tea (which I drank consistently through my first pregnancy), and noticed that red raspberry leaf is an ingredient along with a blend of others (not sure of how many mg / bag as this info is not listed on the box though). (mamanatural.com)
There are a number of good bedtime teas on the market including Yogi Bedtime and Sleepytime. (ultrawellnesscenter.com)