Empagliflozin vs Metformin in PCOS

Inclusion Criteria:

1. Women, aged 18-45 years (inclusive), with confirmed diagnosis of PCOS based on Rotterdam criteria.
2. Presence of both irregular periods and biochemical hyperandrogenaemia
3. Body mass index ≥25
4. Negative pregnancy test during screening visit and agree to use barrier contraception during the study period.

Exclusion Criteria:

1. Non-classical 21-hydroxylase deficiency, hyperprolactinaemia, Cushing's disease and androgen-secreting tumours will be excluded by appropriate tests.
2. Confirmed diagnosis of diabetes or pre-diabetes.
3. Ongoing, inadequately controlled thyroid disorder (subjects on thyroid hormone replacement therapy must be on stable dose for at least 3 months before screening day)
4. History or presence of malignant neoplasms within the last 5 years (except basal and squamous cell skin cancer and in-situ carcinoma).
5. History or plan of any form of gastrointestinal tract surgery.
6. History of pancreatitis (Acute or Chronic).
7. Any disorder which in the opinion of the investigator might jeopardize subject's safety.
8. Subjects who are on any of the following medications within 3 months of recruitment:

   * Metformin or other insulin-sensitizing medications (e.g., pioglitazone )
   * Hormonal contraceptives (e.g., birth control pills, hormone-releasing implants, etc.)
   * Anti-androgens (e.g., spironolactone, flutamide, finasteride, etc.)
   * Clomiphene citrate or estrogen modulators such as letrozole
   * GnRH modulators such as leuprolide
   * Minoxidil
9. Female who is pregnant, breast feeding or intended to become pregnant or of child bearing potential not using adequate contraceptive methods.
10. eGFR\<60
11. Hypersensitivity to lactose
12. Severe hepatic impairment (ALT \>3 times ULN)
13. Women with history of recurrent urinary tract infections.
14. Haematocrit above the upper limit of normal range.
15. Have been involved in another medicinal trial (CTIMP) within the past four weeks.
16. Known hypersensitivity to the Investigational Medicinal Products or any of their excipients.