Now that I'm 37 weeks pregnant, I seem to have a large number of acquaintances suggesting herbal medicines to me the speed up labor or thin the cervix. The two most common have been raspberry leaf tea and evening primrose oil.
I did some research on google scholar about these ones and found a couple of studies indicating that these herbal medicines were ineffective or actually increased the length of labor.
Raspberry leaf – Should it be recommended to pregnant women?
Effect of Maternal Raspberry Leaf Consumption in Rats on Pregnancy Outcome and the Fertility of the Female Offspring
Oral evening primrose oil
I don't have a medical background (and I don't have access to a lot of the literature out there), so my ability to interpret these results is somewhat limited, but it seems pretty clear that these herbal medicines are not proven to be effective.
I also found a study examining a whole bunch of different herbal remedies for labor, but it doesn't really go into detail regarding the results (it just surveys a bunch of women)
It made me wonder, since there are also broad studies that look at multiple different commonly-recommended herbal medicines (or at least papers that aggregate other studies), are there any more broad papers that indicate a commonly-recommended herbal medicine is actually more effective than the others and that has actually been established to be effective at speeding up labor?
It would be nice to know if I should be ignoring my acquaintances advice entirely, or if their recommendations do have some merit.