Background: One of the negative inducers of the internal environment is inflammation; amongst external factors the most significant is polyetiological stress. One of the promising pharmacological methods of health protection is based on natural biologically active compounds, especially complex phytoadaptogen (CPhA). The aim of thie study: This study evaluated the seasonal rhythms in periodontal microcirculation under combined stress (CS), and the possibility of seasonal prophylaxis with complex phytoadaptogen – Glycyrrhiza glabra, Rhodiola rosea, Acantopanax senticosus. Materials and methods: The study was carried out on 60 Wistar male rats (230±20 g) kept in natural light. The complex phytoadaptogen is composed from official 70% tincture of Glycyrrhiza glabra and 40% tincture of Rhodiola rosea, Acantopanax senticosus in the ratio 2:1:1. Results: Under seasonal differences in meteorological data in healthy rats systolic flow velocity (S) in winter was higher than in summer (P=0.005); under the effect of CS on the gum there was a seasonal difference of S (P=0.03) with a maximum in winter (P=0.007); decrease in both seasons of the Gosling index (PI) (winter (P=0.008), summer (P=0.005)), peripheral vascular resistance (RI) (summer (P=0.005), winter (P=0.01)), Stewart index (SD) (summer (P=0.005), winter (P=0.01)). Under administration of CPhA (groups 5 and 6) the microcirculation indicators in the gum and peripheries were statistically significantly different from those in experimental periodontitis, and there were fluctuations within the confidence interval of the norm (p<0.01), seasonal differences RI (P=0.005) and SD (P=0.03), there was a significant leveling of the damaging effect of CS. Conclusion: Application of a novel herbal extract inhibited alveolar bone resorption by the reduction of osteoclastic activity, maintained the integrity of periodontal structures, and normalized the periodontal microcirculation in summer and winter.