If you have high blood glucose levels, you may take metformin hydrochloride, an oral anti-hyperglycemic medication that lowers blood sugar. Metformin may also help you lose weight in some cases by decreasing your appetite. Clinical studies have not proven that metformin helps you lose weight if you don't have Type 2 diabetes or other metabolic disorders that cause insulin resistance. It may help prevent weight gain or cause modest weight loss if you're taking antipsychotic drugs that cause weight gain. Metformin comes in several doses, including a 500-milligram extended release form, which you may find easier to take.
Metformin might help you lose weight if you have metabolic syndrome or polycystic ovary disease, both associated with insulin resistance. The pancreas releases insulin in response to glucose in your bloodstream. Insulin helps cells remove glucose from the bloodstream. When you eat large amounts of high-carb foods, the pancreas may overproduce insulin to keep up. Eventually, your cells stop responding to the insulin and your blood glucose levels rise. Because your cells feel starved for energy, you feel hungry all the time and may crave carbohydrates. Metformin helps cells respond better to insulin, so you don't feel as hungry. Insulin can also cause your liver to convert extra calories to fat.
Metformin decreases the amount of glucose your liver produces, and also decreases the amount of glucose absorbed in your intestines. Decreased amounts of glucose in your bloodstream results in less glucose absorbed by your cells. When you absorb less glucose, you lose weight.
An Indian study published in the March 2011 "British Journal of Clinical Pharmacology" reported that metformin increased weight loss in people taking olanzapine, an antipsychotic drug associated with weight gain. A review of studies conducted by researchers from the University of Pittsburgh reported in the April 2005 "Annals of Family Medicine" found insufficient evidence in nine studies for the effectiveness of metformin as a weight-loss drug in people who did not have either Type 2 diabetes or polycystic ovary syndrome. Extended-release metformin has the same effectiveness as immediate-release forms and produces fewer side effects, according to a study published by Thomas Jefferson University researchers in the January 2011 issue of "Postgraduate Medicine."
Studies have not proven metformin more effective for weight loss compared to a placebo in most studies, eMed TV reports. However, metformin does appear to reduce weight gain, which often accompanies use of anti-hyperglycemic drugs. For that reason, metformin might have benefits if you're already struggling with overweight and need to take medications for Type 2 diabetes. The extended-release metformin may reduce initial symptoms that can occur with metformin, such as diarrhea and nausea. Because it's taken once a day, it may also be more convenient to take.
- eMedTV; Metformin and Weight Loss; Kristi Monson, Pharm.D., et al.; December 2008
- Drugs.com; Metformin Extended Release
- Dr.Mirkin.com; Metformin (Glucophage) for Weight Loss; Gabe Mirkin, M.D.
- "British Journal of Clinical Pharmacology"; Metformin for Olanzapine-Induced Weight Gain: A Systematic Review and Meta-Analysis; S. Praharaj, et al.; March 2011
- "Annals of Family Medicine"; Metformin as Treatment for Overweight and Obese Adults: A Systematic Review; Kara M. Levri, M.D., et al.; April 2005