This research study aims to investigate the effect of adding Alpha lipoic acid (ALA) supplement to letrozole treatment in infertile women with polycystic ovary syndrome (PCOS). The study will include 150 PCOS participants seeking fertility treatment. They will be randomly divided into two groups - control and intervention. Both groups will receive standard PCOS care including lifestyle counseling. The control group will be treated with letrozole only. The dose will start at (2.5 mg) for 5 days and can increase up to (7.5 mg) based on response. The intervention group will take ALA supplements along with letrozole treatment. ALA tablets (600mg) will be given three times daily starting from day 3 of the menstrual cycle till human chorionic gonadotropin (HCG) injection day. Letrozole dose for the intervention group will also follow the same incremental protocol as the control group. Patient monitoring will involve trans-vaginal ultrasound scans on certain cycle days to check follicle growth and the thickness of uterus lining. Once a follicle reaches 18mm in size, an intramuscular HCG injection will be given. Couples will be asked to have intercourse 36 hours after the injection. Pregnancy will be tested two weeks later if menstruation does not occur. Metabolic, hormonal, and ultrasound parameters will be recorded at baseline and follow-ups. All adverse effects of the treatment will be noted. The study period will be a maximum of 3 treatment cycles or untill pregnancy is achieved. Outcome measures include ovulation and pregnancy rates. The effect of ALA on metabolic parameters (fasting glucose, fasting insulin, BMI and HOMA-IR), hormone levels (mid-luteal progesterone and serum estradiol), and follicular growth will also be assessed. Proper sample size and randomization methods will be followed. A Statistical analysis of collected data will help determine if ALA has additional benefits when combined with letrozole for PCOS fertility treatment. Finally, the results will be statistically analyzed. Statistical analysis will be done using the SPSS statistical software package.