Health functional food is referred to a food prepared or processed from specific components or ingredients for functionality beneficial to the body through extraction, concentration, purification, blending and other methods. The demand for health functional foods is steadily increasing, and red ginseng is the most demanded food among women in the 50s, followed by multivitamin, omega-3, glucosamine and aloe. To date, there is insufficient evidence on the effect of red ginseng on exercise capacity, somatic symptom and cognitive performance in healthy individuals. Moreover, evidence is insufficient that a nutritional dose of vitamin or mineral reduces the incidence of cardiovascular disease and cancer, or mortality rate. A steady intake of oily fish is recommended to prevent the incidence of cardiovascular disease for postmenopausal women. Consumption of omega-3 fatty acids is expected to prevent cardiovascular disease in postmenopausal women with almost no intake of oily fish and those not taking statins. It still remains controversial whether glucosamine is effective in the treatment of osteoarthritis. Hence, physicians should fully inform patients with all controversial information about the effectiveness of glucosamine when prescribing glucosamine for patients with osteoarthritis.