Why Is 'benforce-M' Prescribed For Irregular Periods?

Hi Doctor, Good day, I am 33 years, height - 4.11 inches and weight is 65kgs, I have irregular periods from past 5 years. Doctor has suggested me to take BenForce-M (Metformin with Benfotiamine Tablets) 1st 7 days before food, after completing 7 days he has suggested me to take 2 tablets before food, totally i have received 50 tablets. Could you please suggest me for that is used, i will be very grateful to you. Thank you in advance :-)