Venoactive Drugs (VADs) are an integral part of the conservative management of chronic venous diseases (CVD). The mechanism of action of these drugs is well-described. It targets key ways of pathogenesis of CVD, such as loss of venous tone, chronic inflammation in the venous wall and its subsequent remodeling, increased capillary permeability, and insufficient compensatory function of the lymphatic system. The clinical efficacy of VADs concerning quality of life, CVD signs and symptoms, has been demonstrated in numerous randomized controlled trials (RCTs), meta-analyses, and systematic reviews. The incidence of adverse events appears to be low, and the use of VADs is considered a safe method of treatment for CVD symptoms. The most extensively studied group of VADs are flavonoids, which include drugs based on diosmin and rutosides. Diosmin, a principal flavonoid used in drugs, exhibits pleiotropic effects. It slows the degradation of norepinephrine in the venous wall, potentiating its effect and enhancing venous tone. Diosmin possesses anti-inflammatory activity by inhibiting leukocyte adhesion and the synthesis of pro-inflammatory mediators. It decreases capillary and venule permeability, which is directly associated with reduced fluid movement into the tissues. RCTs show that diosmin is effective in managing diseases of other organs and systems which also present with edema.