We sometimes think of changes in body weight as a side effect of some medications, but this can be an important part of treatment also. Since type 2 diabetes is often associated with excess weight or obesity, the selection of medications should also take into account the potential for effects on weight, whether positive or negative.
Guidelines for the treatment of type 2 diabetes include recommendations for drug therapy, starting with metformin. Metformin is very effective at lowering blood sugar and helps with weight loss also. It has even been shown to be effective for weight loss in patients who have prediabetes or insulin resistance.
Another class of medications that can cause weight loss is GLP-1 receptor agonists which include Byetta, Victoza, Trulicity, Ozempic, and others. These drugs increase satiety, meaning people feel full and stop eating earlier. Saxenda is a GLP-1 agonist that is marketed only for weight loss.
SGLT-2 inhibitors can cause weight loss also. These drugs cause the body to excrete sugar in the urine. This leads to weight loss due to calories leaving the body without being absorbed. There is typically some extra fluid loss with these drugs also, adding to weight loss. This class of medication includes Farxiga, Invokana, Jardiance, and Steglatro.
Pramlintide (Symlin), an injectable medication given with each meal, has also been associated with modest weight loss in some studies.
Some medications for diabetes can cause weight gain, which is often not desirable. Medications like pioglitazone, glyburide, glimepiride, glipizide, and insulin are associated with some weight gain. These drugs are very effective at lowering blood sugar and may be needed for certain patients. These medications are also older and available in less expensive generic versions which is also an important factor in drug selection.
Some medications for diabetes do not have an effect on weight one way or another. These include DPP-4 inhibitors (Januvia, Onglyza, Tradjenta), meglitinides (repaglinide and nateglinide), and alpha-glucosidase inhibitors (acarbose and miglitol).
It is important to note that the weight loss or weight gain with any of these medications is typically not very large. For many people it may be a difference of less than ten pounds. Lifestyle changes including dietary modifications and exercise are integral parts of any diabetes regimen and should be initiated at diagnosis and continued as long as possible.