Aim of the studyPCOS is an endocrine condition that results in enlarged ovaries with tiny cysts on the margins. The present study aims to investigate the beneficial effect of polyherbal formulation in Letrozole induced PCOS in female Albino Wistar rats. Materials and methodsAcute toxicity study of the polyherbal formulation by administering a single dose (2000 mg/kg) was done in female Albino Wistar rats (20 weeks, 250 g) following OECD guideline 423. For PCOS induced study female Albino Wistar rats were divided into six groups (6 animals/group). Group I (control) was given 0.5% carboxymethylcellulose (CMC) suspension daily as vehicle control. Letrozole (1 mg/kg) was orally administered for 21 days in Group II to VI for induction of PCOS. After induction of PCOS, animals were treated with standard drug (Group III- Clomiphene citrate- 1 mg/kg) and polyherbal tablets (Group IV – 500 mg/kg, Group V- 750 mg/kg, and Group VI – 1000 mg/kg) up to 50 days. Vaginal smears were taken daily to check the estrous cycle. Body weight was measured weekly. Blood samples were withdrawn on 0,21 and 50 days for the determination of fasting blood glucose, lipid profile, LH, FSH, and hormonal levels. ResultsAdministration of letrozole caused the abnormality in serum sex hormone profile, lipid profile, glucose, and the estrous cycle. The treatment with polyherbal formulation significantly decreased (P < 0.0001) the level of testosterone and improved estradiol and progesterone levels (P < 0.0001). There was a decrease in elevated glucose levels from 71.51 ± 0.15 mg/dl in disease induced group to 57.33 ± 1.90 mg/dl in treatment groups. The triglycerides level was normalized to 33.41 ± 1.81 mg/dl and HDL level was increased to 40.63 ± 1.35 mg/dl in treatment groups. The polyherbal formulation by exerting its beneficial effect also caused the disappearance of the cysts in the ovaries. ConclusionThe polyherbal formulation was found to be effective in PCOS. The effect may be attributed to the individual herbs reported having a significant effect on the pathophysiology of letrozole induced PCOS.