Used to treat Diabetes Type 2 primarily with another drug that is used as an antimalarial drug.

Can also be used is some cases with Diabetes Type 1. 

It is used less often in Type 1

Biguanide is a molecule and is used in these medications

Action:
   -    This medication can lower the levels on insulin in plasma
   -    Helps to increase the cells ability to absorb glucose
   -    This will improve the blood glucose levels in the blood.

Types:

.         Metformin
  Uses: Diabetes Type 2 and Type 1

.         Proguanil
  Uses: Antimalarial drug

Phenformin and Buformin were taking off the market due to considerable side effects.

Side Effects:
   -    diarrhea
   -    hypoglycemia
   -    fatigue
   -    abdominal discomfort
   -    others