• To assess safety of Dietressa in the dose of 6 tablets daily within 24 weeks in treatment of obese patients (BMI 35,0-39,9 kg/m2).
• To assess clinical efficacy of Dietressa in the dose of 6 tablets daily after 24 weeks of therapy in reducing body weight in obese patients (BMI 35,0-39,9 kg/m2).

In general, patients will be observed during 24 weeks of trial.

Inclusion Criteria:

1. Outpatient subjects with BMI 35,0-39,9 kg/m2.
2. Males or females aged from 18 to 65 years.
3. Use of and compliance with contraception methods by patients of reproductive age, of both sexes.
4. Presence of the patient's information sheet (informed consent form) for participation in the clinical trial.

Exclusion Criteria:

1. Symptomatic (secondary) obesity:

   • with established genetic defect (including as a part of known genetic syndromes affecting multiple organs): Prader-Willi syndrome, Alstrom's syndrome, Laurence-Moon-Biedl syndrome, Dercum's syndrome etc.
   • cerebral (adiposogenital dystrophy, Babinski-Frohlich syndrome): brain tumors; dissemination of systemic lesions, infectious diseases; against mental diseases.
   • endocrine: hypothyroid; hypoovarial; pituitary-hypothalamic disorders; adrenopathy.
   • iatrogenic (caused by drug administration, for example, insulin, glucocorticosteroids, neuroleptics etc.).

2. Compliance with a diet prescribed and monitored by the doctor to reduce body weight within 6 months before enrollment.

3. Participation in the lifestyle modification program within 6 months before enrollment.

4. Patients who quit smoking within 6 months before enrollment, or intending to quit smoking during the period of participation in the trial, as well as intending to begin smoking during the trial.

5. Uncontrolled arterial hypertension (patients with 1-3 degree AH, receiving no adequate antihypertensive therapy).

6. Type 1 and 2 diabetes mellitus.

7. Edema syndrome with various etiology (chronic cardiac failure, nephrotic syndrome, hepatic cirrhosis).

8. Circulatory failure, IIА degree and above.

9. Decompensated cardiovascular disease, liver, kidney or gastrointestinal tract disease, metabolic, respiratory, endocrine, hematologic disease, peripheral vessel disease or another medical state. Oncological disease.

10. Diseases and states, which, in the investigator's opinion, may prevent the patient from participating in the trial.

11. Past history of bulimia / non-drug anorexia.

12. Past history of any bariatric surgeries.

13. Lipoplasty underwent less then 1 year prior to screening visit, or cavitary surgery less then 6 months prior to screening visit.

14. Surgeries scheduled within 6 months.

15. Allergy to/intolerance of any of the drug components used during treatment.

16. Malabsorption syndrome, including congenial or acquired lactase or another disaccharidase insufficiency.

17. Administration of drugs specified as "Prohibited concomitant therapy", within 6 months before enrollment.

18. Pregnancy, breast-feeding, unwillingness to comply with contraception methods during the trial and within 30 days after completion of participation in the trial.

19. Drug and alcohol consumption (over 2 alc. units daily), mental diseases.

20. Legal incapacity or limited legal capacity.

21. Patients, who, in the investigator's opinion, will fail to observe the requirements during the trial or adhere to the studied drug administration procedure.

22. Participation in other clinical trials within 3 months before enrolment in this trial.

23. Presence of other factors, complicating the patient's participation in the trial (e.g., planned lengthy business and other trips).

24. A patient is a part of the center's research staff, taking a direct part in the trial, or an immediate family member of the investigator. Immediate family members are defined as spouses, parents, children or siblings, regardless of whether full blood or adopted.

25. The patient is employed with Scientific Production Firm Materia Medica Holding LLC, i.e. is the company's employee, part-time employee under contract, or appointed official in charge of the trial, or their immediate family.