By Moira Lawler
Medically Reviewed by Kacy Church, MD Reviewed: October 21, 2020
9-11 minutes
“Metformin is so popular because it is inexpensive and can reduce the glucose level and A1C [blood sugar average for three months] the most compared with other diabetes medications,” says Dr. Griebeler.
A review published in July 2014 in the Journal of Research in Medical Sciences reported that metformin is 30 percent more effective at reducing the risk of death and complications than insulin, glibenclamide, and chlorpropamide, which are sulfonylureas, a class of diabetes drugs.
Metformin is generally part of a diabetes-maintenance plan, and it works in conjunction with a healthy diet and exercise routine. It’s usually taken twice a day with meals and can take anywhere from one week to two months to see blood sugar improvements, according to the Mayo Clinic.
Metformin Brand Names
Metformin is available under the brand names Fortamet, Glucophage, Glumetza, and Riomet, according to MedlinePlus. The U.S. Food and Drug Administration (FDA) has only approved metformin for people with type 2 diabetes, according to MedlinePlus. It’s also been shown to be a helpful preventive measure for people at risk of developing the disease and those with prediabetes, which is the precursor of type 2 diabetes, though the FDA has not yet approved metformin for those uses.
Cost of Metformin
Susan L. Besser, MD, a diplomate of the American Board of Obesity Medicine and a primary care physician with Mercy Medical Center in Overlea, Maryland, says metformin is widely available — though by prescription only — and is relatively affordable. Griebeler says that in some locations, a three-month supply may cost just $10. It’s also known to be safe, with minimal side effects. Researchers behind a review published in August 2017 in the journal Drug Design, Development, and Therapy reported that it has a “good safety profile and is associated with low cost.”
The Studied Benefits of Metformin for Preventing Type 2 Diabetes Complications
Metformin is prescribed to treat high blood sugar, but researchers have found that it has many other benefits to offer patients with type 2 diabetes and can reduce the risk of several other health concerns, including:
- Cancer In a study published in Gastroenterology, participants had a 62 percent lower risk of pancreatic cancer when taking metformin. The study also reports that the medication may help slow the spread of colon, breast, ovarian, prostate, and lung cancer cells, perhaps due to the medication’s antioxidant activity.
- Stroke A study published in February 2014 in the Journal of Stroke and Cerebrovascular Diseases followed subjects with type 2 diabetes for four years and found that 9.2 percent of those who took metformin had a stroke, compared with 17.5 percent of those who did not take it.
- Dementia Metformin can reduce the risk of dementia, which people with type 2 diabetes are at risk of developing, according to a study published in October 2014 in The Journals of Gerontology, Series A: Biological Sciences, and Medical Sciences. Alzheimer’s disease is the most common form of dementia, accounting for an estimated 60 to 80 percent of dementia cases, notes the Alzheimer’s Association.
- Heart Problems A review published in August 2017 in Nutrition, Metabolism, and Cardiovascular Diseases found that metformin helps protect against coronary events and heart failure. “Metformin can also improve [one’s] cholesterol profile,” Griebeler says. Per the Centers for Disease Control and Prevention (CDC), people with diabetes are 2 times more likely to die of heart disease than people without diabetes.
- Type 1 Diabetes Metformin may help manage blood sugar in the second most common type of diabetes, type 1, especially in those who are overweight or obese. In a small yearlong study published in 2018 in BMC Endocrine Disorders, individuals treated with metformin and insulin therapy saw lower glucose levels, reduced markers for metabolic syndrome, and less reliance on insulin compared with participants treated with insulin alone. While the aforementioned health improvements happened regardless of changes in weight and blood lipid levels, the study authors reported that on average, those people in the metformin and insulin group lost more weight than the group that took only insulin. Yet because the study was small and relatively short term, more research is needed.
- Age-Related Macular Degeneration (AMD) Metformin also has potential benefits for your eyesight. In fact, the diabetes medication may reduce the risk for AMD by 58 percent, according to a case-controlled retrospective study published in April 2019 in Investigative Ophthalmology and Visual Science. AMD is the most common cause of blindness among people ages 50 and older, according to the National Eye Institute. In the study, researchers found that metformin, but not other medications (such as DPP-4 inhibitors, SSRIs, antidepressants, and statins), were associated with a reduced odds of AMD development.
The Potential Benefits of Metformin Beyond Managing Type 2 Diabetes
More and more research suggests that the benefits of this medication aren’t reserved for people with type 2 diabetes. Griebeler says that even though metformin is only approved for the treatment of type 2 diabetes, it’s being used off-label to treat weight reduction, polycystic ovarian syndrome (PCOS), infertility, prevention of diabetes, prevention of pregnancy complications, and obesity.
It’s been shown to have a positive effect on the following health issues for people without diabetes:
Osteoarthritis According to astudy published in May 2019 in Arthritis Research and Therapy, metformin can help people with obesity and osteoarthritis. The researchers found that metformin helped people lose cartilage at a lower rate than those who did not take metformin, and they observed that the medication reduced participants’ risk of needing a total knee replacement, which is a possible complication of this health condition.
Alzheimer’s Disease A study published in April 2017 in Alzheimer Disease and Associated Disorders involving 20 people without type 2 diabetes found that metformin improved executive function skills, learning, memory, and attention. The randomized, controlled trial was short (eight weeks) and small (only 21 participants), though, so more research is needed.
Obesity Metformin has been shown to result in weight loss among people with type 2 diabetes, per the Mayo Clinic, so researchers were interested in seeing if the results would be similar for people without diabetes. “There has been some research that when people who [do not have diabetes but are] overweight are put on metformin, it helps with weight loss,” Dr. Besser says.
A study published in Experimental and Clinical Endocrinology and Diabetes treated 154 people who did not have diabetes with metformin for six months. The study participants lost nearly 13 pounds (lbs) on average, and researchers found that the medication helped overweight and obese people with insulin resistance, increasing their sensitivity to the hormone. Insulin resistance increases the risk for weight gain, notes the Mayo Clinic.
A meta-analysis of randomized, controlled trials that was published in December 2018 in Endocrine also found that metformin may help people with obesity lose weight. “I have used [metformin] for obesity management — for some with normal sugars, some prediabetic — and it helps,” Besser says. “It’s not an end-all, do-all — it’s not a miracle cure — but it does seem to help.” She says to expect only a modest amount of weight loss, 10 or 15 lbs, but it could be enough to inspire people to stay on the weight loss path. “It’s enough to kick-start things, and for anyone who’s quite overweight, any weight loss is encouraging, and it makes them want to keep going,” Besser says.
Arthritis A study published in 2019 in Current Rheumatology Reviews found that metformin can protect bones, especially during the early stages of rheumatoid arthritis, and decrease inflammation. “I suspect it’s because metformin may work in an anti-inflammatory way,” Besser says.
PCOS Metformin can help promote ovulation among nonobese women with PCOS, which, like type 2 diabetes, involves insulin resistance, according to an article published in June 2014 in the Annals of Translational Medicine. “Diabetes does not cause PCOS, but people with PCOS have a higher risk of developing diabetes,” Besser says. She’s used metformin to treat people with PCOS, a couple of whom managed to become pregnant after they started taking it. According to the Mayo Clinic, metformin can also improve fertility rates among women with PCOS.
The Bottom Line on Using Metformin for Treating Health Conditions
Though the FDA has only approved metformin to treat type 2 diabetes, research shows that it can help with a host of other health benefits for people with or without diabetes. In fact, according to a list of studies on the website for the journal Frontiers, in addition to the health conditions listed above, metformin is currently being explored as a way to treat these issues as well:
- Aging
- Metabolism conditions
- Inflammation