just a quick search, but here is something
LLL says:
"The use of raw green cabbage leaves has been anecdotally reported to reduce engorgement. Mothers who have used this treatment report the use of chilled or room temperature cabbage leaves to be soothing. The advantages of this treatment are its low cost and convenience. One study reported the group using cabbage leaves experienced a slight reduction in perception of engorgement and exclusively breastfed longer (Roberts 1995b). A study comparing the use of chilled cabbage leaves to chilled gel packs found that pain was relieved within 1-2 hours with both treatments, but mothers preferred the cabbage treatment (Roberts et al. 1995a).
The clean, inner leaves of a head of green cabbage can be applied between feedings for several feedings. The leaves should be changed at least every two hours or when they wilt. Mothers should know that there may be some smell of cooked cabbage if they choose this treatment method. They should also know that overuse of cabbage leaves can lead to a reduction in milk supply according to some reports. Cabbage leaves should be used only until the swelling goes down and should be discontinued if a skin rash or other signs of allergy appear."
Also if you are looking to decrease your supply:
"Changing the way you feed your baby can reduce both the overall milk volume and the amount of lactose baby receives, while increasing the amount of fat. Since mothers with oversupply often produce enough milk in each breast for a full feeding, one strategy that can be very successful is to feed the baby on only one side per feeding. If your baby wants to nurse again within two hours, see how he responds if you continue to offer that same side. In the next two hours, offer only the other breast. The breasts should gradually slow down their rate of milk production because milk is being removed less often. This helps down-regulate the milk production rate to match baby's true needs while also reducing the amount of foremilk and lactose baby receives.[3] When you keep baby at the same breast for a longer period of time, it also ensures that your baby is fully draining the breast and getting more of the higher calorie hindmilk."
I have had issue with oversupply and OALD, block feeding has made a huge impact in helping. Good luck, HTH!
