Lecithin has been recommended to combat recurrent plugged ducts. The usual recommended dosage for recurrent plugged ducts is 3600-4800 mg lecithin per day, or 1 capsule (1200 milligram) 3-4 times per day. After a week or two with no blockage, mom can reduce the dosage by one capsule. If there is no blockage within another 2 weeks she can reduce it again by one. Mom may need to continue taking 1-2 capsules per day if stopping the lecithin leads to additional plugged ducts.
Lecithin is a very common food additive, and is found naturally in many other foods. There are no known contraindications to its use by breastfeeding mothers.
The reason why lecithin may help resolve and prevent plugged ducts is not clear. Per Dr. Jack Newman, “It may do this by decreasing the viscosity (stickiness) of the milk by increasing the percentage of polyunsaturated fatty acids in the milk.” Lecithin is an emulsifier (used to keep fats/oils dispersed and in suspension): phospholipid molecules (such as lecithin) contain hydrophobic and hydrophilic elements; the hydrophobic portion has an affinity for fats and oils, and the hydrophilic portion has an affinity for water.
Additional safety information:
Per “The Doctor’s Vitamin and Mineral Encyclopedia” by Sheldon Saul Hendler, MD, Ph.D. (1990, p. 258-269), the maximum dosage of lecithin is 50 grams per day. The maximum dosage recommendation for recurrent plugged ducts is 4.8 grams per day–less than 1/10 of the maximum recommended dosage.
Choline is a component of lecithin – the lecithin sold in health food stores is about 1-2% choline. Rarely, people who take pure choline can develop a fish odor- this is due to a liver enzyme deficiency that impairs choline metabolism. The form of choline in lecithin (phosphatidylcholine) should not cause this problem. If you develop a fishy body odor, stop taking choline supplements and see your physician. People with liver failure may develop this deficiency, as may those with normal livers who take more than 20 grams of (pure) choline per day.
Also, people with a preexisting tendency to depression may become depressed if taking high doses of choline or lecithin. These people should be monitored by a physician.
More information on lecithin and breastfeeding can be found here.