Metformin, Outside the box?

Here is an article for those who like a little more information than just “take this”.

Here are some studies using Metformin for weight loss.  I hope this helps illuminate why this medication may help in weight loss efforts.  Metformin can cause lactic acidosis in populations with decreased kidney function although a very rare side effect it can be a serious complication.  Renal function should be evaluated regularly.  Alcohol can increase the risk of low blood sugar and its symptoms while taking Metformin and should be avoided.

Only take Metformin under the care and supervision of a physician.

Exp Clin Endocrinol Diabetes. 2013 Jan;121(1):27-31. doi: 10.1055/s-0032-1327734. Epub 2012 Nov 12.

Effectiveness of metformin on weight loss in non-diabetic individuals with obesity.

Seifarth CSchehler BSchneider HJ.



The efficacy of metformin for the treatment of obesity has been evaluated in few clinical trials with inconclusive results. Moreover, the effectiveness in a real-life outpatient setting has not been tested until today. In this study we aimed to examine the effectiveness of metformin as a weight reducing drug in obese and overweight patients with regard to their degree of insulin resistance.


We treated 154 consecutive patients with a body mass index ≥27 kg/m(2) in an outpatient setting over 6 months with metformin up to a dosage of 2,500 mg per day. Additionally, we included 45 untreated patients as controls. Patients were monitored for weight changes over 6 months. Before metformin treatment was started insulin sensitivity was determined in all patients by calculating HOMA index and Matsuda index after a 75 g oral glucose tolerance test.


The mean weight loss in the metformin treated group was 5.8±7.0 kg (5.6±6.5%). Untreated controls gained 0.8±3.5 kg (0.8±3.7%) on average. Patients with severe insulin resistance lost significantly more weight as compared to insulin sensitive patients. The percentage of weight loss was independent of age, sex or BMI.


Metformin is an effective drug to reduce weight in a naturalistic outpatient setting in insulin sensitive and insulin resistant overweight and obese patients.

© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

Ann Pharmacother. 2008 Jun;42(6):817-26. doi: 10.1345/aph.1K656. Epub 2008 May 13.


Role of metformin for weight management in patients without type 2 diabetes.

Desilets ARDhakal-Karki SDunican KC.



To evaluate the efficacy and safety of metformin for weight management in overweight and obese patients without type 2 diabetes.


Literature was obtained through MEDLINE Ovid (1950-February week 3, 2008), EMBASE (all years), and a bibliographic review of relevant articles. Key words included metformin, obesity, overweight, and weight loss.


All studies published in the English language that evaluated the effects of metformin on weight in obese or overweight individuals were critically analyzed. Relevant articles were selected for inclusion in this review.


Metformin is first-line pharmacotherapy in the treatment of overweight or obese patients with type 2 diabetes, with beneficial effects on weight in this population. Multiple trials have evaluated the effect of metformin on weight and other metabolic parameters in adults and adolescents without diabetes. Five of 12 trials in adults evaluated weight loss as a primary endpoint. Significant weight reduction was found in 4 of these studies; however, the trials were small and of weak design. Weight reduction was significant in 5 of the 6 adolescent trials; similarly, these studies were limited by weak study design and small patient population. Metabolic parameters (blood pressure, waist circumference, cholesterol parameters, insulin/glucose levels) often showed varying results. Metformin was well tolerated; gastrointestinal effects were the most frequently reported adverse effects.


The weight loss effects of metformin in overweight or obese adults and adolescents without diabetes appear promising; however, trials have been limited by small patient populations and weak design. Metformin may also have a positive effect on metabolic parameters such as waist circumference, fasting insulin and glucose levels, and triglycerides. Further research involving large-scale trials that evaluate weight loss as a primary outcome is necessary to firmly establish the role of metformin in this population.

Int J Obes (Lond). 2008 Jan;32(1):61-72. Epub 2007 Jul 24.


Metformin and body weight.

Golay A


Most patients with type 2 diabetes are overweight or obese, overweight or obesity increases the risk of developing type 2 diabetes and obesity per se is strongly associated with multiple cardiometabolic risk factors. However, many antidiabetic treatments increase body weight. The oral antidiabetic agent, metformin, has been evaluated in hundreds of clinical studies in diverse patient populations during approximately five decades of clinical use. This review summarizes the effects of metformin on body weight, with special reference to studies of longer duration (>/=6 months) as both diabetes and obesity are long-term conditions. Approximately half of studies in drug-naive type 2 diabetic patients demonstrated significant weight loss with metformin compared with baseline or comparator drugs, although pooled analyses have suggested no significant effect versus placebo. Similarly, metformin has been shown to induce weight loss in obese nondiabetic populations, although studies of long duration in this population are scarce. Metformin does appear to mitigate the adverse effects of insulin on body weight. The weight-neutral or weight-sparing effects of metformin constitute a therapeutic advantage in diabetes management where other first-line oral antidiabetic treatments often promote clinically significant weight gain.

PMID:  17653063

[PubMed – indexed for MEDLINE]


Am J Med. 2008 Feb;121(2):149-157.e2. doi: 10.1016/j.amjmed.2007.09.016.

Meta-analysis: metformin treatment in persons at risk for diabetes mellitus.

Salpeter SRBuckley NSKahn JASalpeter EE.



We performed a meta-analysis of randomized controlled trials to assess the effect of metformin on metabolic parameters and the incidence of new-onset diabetes in persons at risk for diabetes.


We performed comprehensive English- and non-English-language searches of EMBASE, MEDLINE, and CINAHL databases from 1966 to November of 2006 and scanned selected references. We included randomized trials of at least 8 weeks duration that compared metformin with placebo or no treatment in persons without diabetes and evaluated body mass index, fasting glucose, fasting insulin, calculated insulin resistance, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and the incidence of new-onset diabetes.


Pooled results of 31 trials with 4570 participants followed for 8267 patient-years showed that metformin reduced body mass index (-5.3%, 95% confidence interval [CI], -6.7–4.0), fasting glucose (-4.5%, CI, -6.0–3.0), fasting insulin (-14.4%, CI, -19.9–8.9), calculated insulin resistance (-22.6%, CI, -27.3–18.0), triglycerides (-5.3%, CI, -10.5–0.03), and low-density lipoprotein cholesterol (-5.6%, CI, -8.3–3.0%), and increased high-density lipoprotein cholesterol (5.0%, CI, 1.6-8.3) compared with placebo or no treatment. The incidence of new-onset diabetes was reduced by 40% (odds ratio 0.6; CI, 0.5-0.8), with an absolute risk reduction of 6% (CI, 4-8) during a mean trial duration of 1.8 years.


Metformin treatment in persons at risk for diabetes improves weight, lipid profiles, and insulin resistance, and reduces new-onset diabetes by 40%. The long-term effect on morbidity and mortality should be assessed in future trials.

Comment in

PMID:  18261504

[PubMed – indexed for MEDLINE


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