In spite of the medical progress in prevention and treatment of ischemic heart disease and obesity these diseases still remain the major health problems in modem society. One of the factors causing the development of ischemic heart disease is high cholesterol level and a large quantity of dietary lipids ingested. The use of common chitosan for fat absorption control may give only a temporary relief to the obese. Besides, common chitosan application may cause side effects, while chitosan oligosaccharide administration may result in a long-term significant weight reduction effect. Fat uptake in the body in presence of chitosan oligosaccharide may be even more decreased by adding to the latter ascorbic acid (vitamin C). Chitosan oligosaccharide, creating a salt bond with ascorbic acid, forms chitosan oligosaccharide ascorbate and thus stabilizes quite an unstable vitamin C, i.e. it acts as a carrier for ascorbic acid. Under the influence of the stomach hydrochloric acid there occurs proteinization of chitosan oligosaccharide and release of ascorbic acid. Some of researchers suggest that decrease of fat absorption in presence of chitosan oligosaccharide ascorbate can be explained by synergetic action of ascorbic acid and chitosan oligosaccharide. Chitosan oligosaccharide ascorbate is capable of controlling cholesterol synthesis by metabolism activation. Moreover, chitosan oligosaccharide ascorbate application enhances immunological functions of the body. Chitosan oligosaccharide ascorbate may be used alone as well as in composition with other biologically active substances for preparing various BAS. Chitosan oligosaccharide ascorbate may be used as one of the basic components in preparations meant for prevention of such alcoholic disorders as headache, stomach upset, diarrhea, fatigue, and the consequences of alcohol impact on the organism like fatty liver, cardiovascular diseases, diabetes. Chitosan oligosaccharide ascorbate is a substrate for glucosamine and hyaluronic acid as well as chondroitin sulfate biosynthesis in the organism. It stimulates their synthesis due to their influence on fibroblasts (fibroblast growth factor) and prevents degradation by collagenase-1 inhibition. It also inhibits lipid peroxide oxidation processes. This preparation prevents aggressive behavior of dystrophic-degenerative joint and spine diseases. The preparation is prescribed in cases of osteoarthritis, osteochondrosis, spondylosis, and scapulohumeral periarthritis. The preparation is non-toxic. It practically has no contraindications except for the individual intolerance and phenylketonuria as well as pregnancy and breast-feeding. The amount of applied chitosan oligosaccharide ascorbate as a BAS component may be limited by a daily consumption of vitamin C. Therefore chitosan oligosaccharide ascorbate is produced with various content of vitamin C (10 - 50% from weight of chitosan oligosaccharide ascorbate). Chitosan oligosaccharide ascorbate is water-soluble and may be included in the composition of makeup preparations, shampoos, etc.