Inclusion criteria:
Aged between 18 and 50 years old
Unilateral or bilateral fibroadenoma of the breast smaller than 3 cm in size, detected by examination and ultrasound. (Diagnostic criteria: 1. in patients under the age of 40 years and patients with masses smaller than 2 cm, the diagnosis will be based on the typical examination and ultrasonographic scan. 2. in patients over 40 years with any size of the mass and patients with masses above 2 cm, the diagnosis will be based on a typical examination, ultrasonographic scan, and pathological investigation of the mass.
Exclusion criteria:
Menopause
Body mass index greater than 29.9 kg / m2
Use of hormonal medications (such as estrogen, progesterone, GnRH agonist, GnRH antagonist, clomiphene, tamoxifen, letrozole, danazol, contraceptive pills, progesterone IUDs, DHEA) and drugs that affect metabolic status, such as weight, glucose, and lipid-lowering agents
Regular consumption of nutritional, medicinal and herbal supplements (such as phytoestrogenic plant compounds, vitamin-rich foods, minerals such as zinc, calcium and ..., multivitamins, vitamins A, E, D, inositol, omega-3, 6)
Breast cancer or history of breast cancer
A family history of breast cancer in first-degree relatives
Hormonal disorders and metabolic diseases such as hypo or hyperthyroidism, metabolic syndrome, diabetes, severe hyperlipidemia - galactorrhea and the pituitary microadenoma
Proven or suspected pregnancy and lactation during the intervention
Other medical conditions, such as cardiovascular disease, epilepsy, renal or hepatic disorders
Contraindications for metformin use (such as hypersensitivity to biguanides, acidemia, heart disease, alcohol consumption, gastroparesis, hepatic disease, hyperthyroidism or hypothyroidism, severe iron deficiency anemia, renal impairments)
History of unwanted and intolerable side effects of metformin (such as abdominal pain, chest pain, chills, cholestasis, diarrhea, dizziness, increased liver enzymes, severe headache, hepatitis, hypoglycemia, megaloblastic anemia, myalgia, nausea, Palpitations, rash, rash, vomiting)