i have had 3 kids..so far...my first 2 labours were long, 18hrs. i took along time to dialate. with my 3rd, i took rasberry leaf tablets and had a 5hr labour. i dialated alot quicker. im 2 weeks of having my 4th, and am taking the tablets again.
the tea isnt as strong as the tablets, and i think you have to drink alot for it to be effective. you can buy 2 brands of rasberry tablets, the blackmores, which you need to take more of and the mg per tablet is less than the natures own brand. and they are cheaper. so i take the natures own, and a few extra than is reccomended from about 36weeks. i find that when i start to take them, my braxton hicks increase, and i think thats a good thing as it is preparing you for labour.
so that my experience, and would recommend them to anyone!