ABSTRACT Objective — to increase the effectiveness of early diagnosis and to develop a differentiated approach to the treatment of adolescent girls with primary dysmenorrhea (PD). Material and methods. The study was conducted on 100 adolescent girls aged 15 to 17 years, diagnosed with primary dysmenorrhea, who were initially divided into study and control groups depending on the presence or absence of undifferentiated dysplasia of connective tissue (UDCT). Then, to compare the two proposed treatment regimens, each group was divided into 2 subgroups. Basic therapy included drug NSAIDs (Meloxicam 15 mg) and vitamin-mineral complex with a content of Calcium 1000 mg and vitamin D3 800 IU. The second scheme — the basic treatment was added to the drug L-carnitine 800 mg, affecting collagen formation. Self-assessment of menstrual pain was performed using McGill’s pain questionnaire. The levels of free hydroxyproline, MMP-2 and MMP-9, tumor necrosis factor α and serum magnesium were determined. Results. In adolescent girls with UDCT, the level of free blood hydroxyproline was almost 2 times higher than in patients with PD without UDCT (276.78±117.1 ng/ml and 142.64±90.4 groups, p<0.05). In both groups, no cases of magnesium deficiency in the blood were detected. In the analysis of biochemical parameters in serum after treatment, in all groups all blood parameters significantly improved-free hydroxyproline decreased 3 times, MMP-2 — 2.5 times, TNF-α —1.5 times, and MMP-9 increased 5 times (p<0.05). Conclusions. The effectiveness of the proposed treatment of primary dysmenorrhea — the use of NSAIDs in combination with vitamin and mineral complex, including calcium and vitamin D, is confirmed not only by clinical data, but also by biochemical studies (reduction of free hydroxyproline 2.5 times, MMP 2—3 times, TNF-α — 1.5 times and increase of MMP-9 in 4 times (p<0.05).Thus, the proposed therapy with NSAIDs and vitamin and mineral complex, including calcium and vitamin D, it is advisable to appoint patients with primary dysmenorrhea, with signs of PDST, to improve the quality of life in adolescent girls.