No it does not induce labor. You are supposed to take it weeks before imams it helps tone your uterine muscles to create more effective contractions. Taking it at 39 weeks will not do anything. It needs to build in your system.

Unfortunately, RRL tea doesn't start labour, but if taken throughout the pregnancy, strengthens the uterus for a faster (and possibly earlier) labour. What you could try though is basil and oregano tea. Those two herbs can bring on uterine contractions in high doses, although it's terrible to get down (I hear). If you're past your due date and have been given the green light to start trying a natural induction, it's worth a try! Here's a quick recipe I found online.