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The Effects of Metformin Therapy on Changes in Metabolic, Vitamin B12, Iron Status, Erythropoietin, and Hematological Parameters Among Women With Polycystic Ovary Syndrome: A Double-Blind Randomized Controlled Trial

ClinicalTrials.gov · COMPLETED, 2026

400 participants

Abstract

This double-blind, placebo-controlled, parallel-group randomized controlled trial evaluated changes in metabolic, vitamin B12, iron-status, erythropoietic, and hematological parameters among women with polycystic ovary syndrome (PCOS) receiving metformin therapy.

Women aged 18-40 years with a diagnosis of PCOS confirmed by a specialist in Obstetrics and Gynecology were randomly assigned in a 1:1 ratio to either a metformin intervention group or a matching placebo group. Participants in the metformin group received a total daily dose of 1500 mg metformin, administered in three divided doses with meals, while participants in the control group received a matching placebo. Both groups continued to receive routine clinical care.

Clinical and laboratory assessments were performed at baseline, 3 months, and 6 months. The study evaluated metabolic measures, including fasting blood glucose, serum insulin, HOMA-IR, total cholesterol, triglycerides, LDL-C, HDL-C, and body mass index. Iron-status measures included serum iron, total iron-binding capacity, ferritin, and transferrin saturation. Serum vitamin B12 and erythropoietin were also assessed, together with hematological parameters including hemoglobin, hematocrit, red blood cell indices, white blood cell counts and differential counts, and platelet count.

The study enrolled 400 participants, with 200 participants initially allocated to each treatment group. After loss to follow-up, 300 participants completed the required…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 400 participants or records.

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