The aim of this work is to study the content of biologically active substances in medicinal plants when treated with bacterial fertilizer. As part of the experiment, studies were conducted on growing Salvia Sclarea L using environmentally friendly biofertilizers (bacterial fertilizer TERIA-S). The use of these fertilizers stimulates the development of both the root system and the above-ground part of the plant. Standard methods of soil microbiology were used to analyze the agrochemical and microbiological composition of the soil in which the plants were cultivated. Cultivation of Salvia Sclarea L. using TERIA-S was first carried out in the laboratory and then in the field. After harvesting the Salvia Sclarea L., the content of phenolic compounds was studied using the Folin-Ciocalteu method. Then extraction and analysis were carried out using high-performance liquid chromatography (HPLC). The antimicrobial activity of phenolic compounds was studied using the well-diffusion agar method. The plants treated with the biopreparation exhibited superior performance across all phenological phases compared to the control group. Notably, the root system of the treated plants was 1.5 times longer and more robust, indicating a significant enhancement in growth and vigor. High-performance liquid chromatography (HPLC) analyses revealed the presence of several bioactive compounds within the Salvia Sclarea L samples. Specifically, kaempferol was detected in all samples, while quercetin was identified in the butanol and ethyl acetate fractions. Additionally, apigenin and luteolin-7-glycoside were present in the butanol fraction, suggesting that these compounds may contribute to the plant's bioactivity. The ethanol fractions of Salvia Sclarea L exhibited considerable antioxidant activity, with a recorded inhibition of 79.80 ± 0.14%. Furthermore, these fractions demonstrated antimicrobial efficacy against Bacillus subtilis and Candida albicans, with inhibition zones measuring 12 mm for both microorganisms. These findings highlight the potential of Salvia Sclarea L, particularly its ethanol extracts, as a source of bioactive compounds with both antioxidant and antimicrobial properties. The observed enhancements in plant growth and secondary metabolite production suggest that the biopreparation not only supports plant development but also may contribute to the increased production of compounds with pharmacological relevance.