Abstract
Background:
Among women in their reproductive years, hypothyroidism is a prevalent endocrine condition linked to insulin resistance and abnormalities in ovarian function.

Aim:
The current study sought to determine how metformin treatment affected TSH levels, thyroid morphology in hypothyroidism, and ovarian alterations in PCOS. It also sought to determine whether metformin was beneficial as an insulin sensitiser.

Methods:
Four equal groups of forty adult, healthy female albino rats of the local strains weighed an average of 150–170 grammes apiece. Group ΛII and Group IV received propylthiouracil (PTU) dissolved in distilled water (15 mg/kg body weight) orally for 45 days, while Group I received distilled water orally for 90 days. Group ΛΙ received distilled water orally daily for the first 45 days of the study, and then received metformin (50 mg/100 g body weight) daily from the 46th day of the study until the end (90th day). Group ΛII received 1 millilitre of distilled water orally every day from the 46th day of the study until the study's 90th day. Group IV was administered metformin orally at a dose of 50 mg per 100 g body weight every day starting on the 46th day of the research and continuing until the 90th day. Biochemical measurements, thyroid, and ovarian histology were examined.

Results:
These findings supported the hypothesis that thyroid hypofunction is linked to disrupted metabolic and ovarian function. They also showed that metformin treatment improved thyroid and ovarian changes in a rat model of hypothyroidism.

Conclusion:
The anti-inflammatory and antioxidant characteristics of metformin were confirmed, as they enhanced ovarian function alterations while having no influence on ovarian modifications in the rat model of hypothyroidism. These results showed that metformin had no effect on ovarian architecture in euthyroid rats.

Key words: Metformin; Propylthiouracil; Hypothyroidism; Ovary.