Lecithin can cause side effects such as diarrhea and nausea, fullness and abdominal pain, according to WebMD. However, lecithin is likely safe for most users. The body’s cells use lecithin to transmit nerve impulses.
Lecithin, found naturally in many foods, including egg yolks and soybeans, also comes in supplement form, notes WebMD. Manufacturers often use it as a food additive and as an ingredient in some eye medications. Studies suggest that lecithin may be useful in treating liver disease by reducing the accumulation of fat in the liver. However, insufficient evidence exists as to its efficacy in some of the other treatments for which natural practitioners often recommend lecithin, including high cholesterol, anxiety, eczema and memory disorders such as Alzheimer’s disease.