It is intended to find novel pharmaceutical use of sphingomyelin and to provide preventive or therapeutic agents for various diseases as well as a food and drink product and feed comprising any of these agents. The present invention provides a pharmaceutical agent which contains sphingomyelin as an active ingredient and is any of the following agents: 1) a sialomucin secretion promoter, 2) an agent for preventing drunken sickness (hangover), 3) an antiallergic agent, 4) an antioxidant, 5) an agent for defending against infection, 6) a hair growth agent, 7) a therapeutic agent for demyelinating disease, 8) an anti-pigmentation agent, 9) an anti-inflammatory agent, and 10) an agent for improving learning ability. The present invention also provides a food and drink product or feed, characterized by comprising the agent. It is preferred that the sphingomyelin should be derived from milk.