This study aimed to determine the effects of flaxseed supplementation on metabolic biomarkers in those with polycystic ovary syndrome (PCOS)⁽¹⁾. 48 participants with PCOS were randomized into either a group receiving 30g of flaxseed powder per day with lifestyle modifications or a group receiving lifestyle modifications alone over 12 weeks. Biochemical, anthropometric, and nutritional factors were evaluated at the beginning and end of the study. Both groups showed a significant reduction in body weight and BMI by the end of the study (p<0.05). The flaxseed group observed a significant decrease in body weight (p=0.001), waist circumference (p=0.007), BMI (p=0.001), serum insulin concentration (p=0.021), homeostatic model assessment of insulin resistance (p=0.007), triglycerides (p=0.013), and leptin (p=0.007) and a significant increase in HDL-C (p<0.001) and adiponectin (p=0.017) compared to the control group. Testosterone levels were elevated for both groups at baseline with no significant changes after the treatment. The flaxseed group showed significant improvement in menstrual cycle regulation compared to control. (p=0.37). Overall, this study showed that flaxseed supplementation can improve the status of several metabolic biomarkers in patients with PCOS.