Impact on human leech is complex and multifactorial. It manifests itself at all levels: spiritual, energy, psychological, physiological, biochemical, and others. In leeches, scientists have discovered more than 40 enzymes, under whose influence in all organs and systems of the human restored normal microcirculation of blood, lymph and interstitial fluid. As a result, reduce swelling, inflammation, pain, ischemia, spastic conditions, normal blood blood pressure (lowers high and low rise). It is particularly important to improve blood circulation in all organs, including the most vitally important – brain and spinal cord, endocrine glands, myocardium. Leech therapy has a beneficial effect on the musculoskeletal system – muscles, bones and joints. Thanks to them, dissolve blood clots, benign tumors and scars, increases local and general immunity, improves virtually all physiological and biochemical indices, normalization of metabolic processes (fat, carbohydrate, protein, salt, etc.). Influence of leeches on the human body produces the effect of a powerful reflexogenic impact, as a kind of acupuncture. Leech therapy restores energy, improves mood, relieves irritability, anxiety and depression. The use of leeches increases efficiency, sexuality and creative possibilities, awakens in man the best quality – the love of self and the world around them, tolerance is the growth of spirituality. Leech therapy enhances immunity and self-regulation of the organism. It has long been observed that the maximum therapeutic effect of the use of medicinal leech is achieved when they are placed in the active areas (acupuncture points) of the body. Production rule suggested by nature. It turned out that leech bites man strictly selectively and in certain places. On the effectiveness of hirudotherapy is one of the first places among the modern methods of treatment. Experts have long shown that bleeding causes a change in the lymphocyte count blood plasma. What accounts for its versatility in application and efficacy in the treatment of various diseases such? Numerous studies scientists from different disciplines (biology, zoology, biochemistry, physiology, hematology, genetics, immunology, ecology, applied medicine and so on. D.) Found that in the first place this is due to the amazing composition of leech saliva. Leech saliva contains a large number of biologically active substances and enzymes of natural origin, which, when injected into the blood of the person acting on it is extremely beneficial: activates the immune system, accelerate metabolism, eliminate inflammation. The main components of the saliva of the medicinal leech, has healing effects are hirudin, having anticoagulant properties (ie. E. Prevent blood clotting), and destabilase. Even in the second half of the XX century. succeeded in isolating them as extracts and used in pure form or as a component of a number of medications. The enzymes contained in it, have moschnymiantisepticheskimi (bactericidal) properties. Due to this, they found the best antibiotics, which, unlike preparations obtained by chemical do not contribute to the circulatory system of substances causing adverse reactions. Getting into the blood, biologically active substances leech saliva activates blood circulation, thus improving tissue oxygenation and nutrition. They also have a dissolving effect on existing blood clots and prevent the formation of new ones. Causing capillary bleeding, leech reduces the concentration of blood in the affected area or organ.According to the latest research found out that the anticoagulant properties of the extract obtained from the digestive system of the worm, not only due to the presence of hirudin and destabilase.Apart from these, in the salivary secretions of leeches are a large number of active complex of proteins, which endow it with such a broad spectrum of action.