Diabetes of Type 1 requires supplemental insulin because the beta cells found in the pancreas are unable to produce insulin required by the body. However some diabetics of Type 2 may also require insulin that depends on the peculiarities of each individual case. Some experts are of the opinion that Type 2 diabetics can also be put on insulin to reach their blood glucose and cholesterol levels.
In addition Type 2 diabetics need supplementary glucose as the disorder progresses as the pancreatic beta cells gradually lose their ability to produce insulin. The time highly depends on factors like the patients weight, genetics, diet and activity level.