Metformin and Breastfeeding

Metformin and Other Antidiabetic
Medicines: Are They Safe to Use When
Breastfeeding?


Approximately 15 million women, or one in every nine women, in the United States have diabetes – and health outcomes for female sufferers tend to be worse than they are for men. For instance, women have a four times higher risk of developing heart disease than men do, and they also have a heightened risk of other diabetes-related conditions like kidney disease or blindness. This makes antidiabetic medication, such as metformin, absolutely crucial, though it can rightfully cause concern for pregnant and breastfeeding women.

In a previous post on breastfeeding and diabetes, we mentioned that a diabetic mother – whether they have type 1, 2, or gestational diabetes can continue to breastfeed their baby exclusively for six months or longer. But while breastfeeding itself is okay to do, is it safe to simultaneously take antidiabetics while breastfeeding? Here’s what you need to know.

Taking Metformin While Breastfeeding

Diabetes occurs when your pancreas cannot produce enough insulin, the hormone that controls your blood sugar levels, or when your body cannot use insulin effectively. Over time, this can cause severe damage; aside from the conditions mentioned earlier, 85% of people with type 2 diabetes are overweight or obese.

Metformin is an antidiabetic agent that was FDA-approved in 1994 to treat type 2
diabetes by helping control blood glucose and increasing your body’s insulin
response. Metformin and weight loss likewise have a strong relationship, as the
medication helps patients manage their appetite and cravings to eat fewer calories
overall. The exact mechanism for how Metformin works is not known. Still, studies
suggest that it affects the gut microbiome – which affects how fat is stored and
whether you feel hungry or full, and thus plays a role in weight management.

Other studies have found Metformin to be effective for weight loss among PCOS sufferers and those with insulin resistance. While not as powerful as a glucagon-like peptide-1 (GLP-1) diabetes medication, Metformin is more affordable for patients.

For women who are breastfeeding, Metformin does get into breast milk in small amounts, but studies suggest no negative effects in breastfed infants — though it's best to discuss this with your healthcare provider, of course. Doctors may also prescribe Metformin as a step-up before GLP-1 drugs like Semaglutide, though the jury is still out on whether Semaglutide is safe for use while breastfeeding.

Breastfeeding mother

Semaglutide While Breastfeeding

Arguably, the most well-known brand of Semaglutide today is Ozempic, which was
FDA-approved in 2017 for use in adults with type 2 diabetes. Semaglutide is a GLP-1 receptor agonist that stimulates insulin secretion and inhibits glucagon secretion. All this results in reduced appetite as the body feels fuller for longer due to the slower movement of food from the stomach to the intestines. Due to increased demand, NBC reports that global shortages are expected, prompting the circulation of dangerous counterfeit versions.

Given rising safety concerns, diabetic moms may worry about whether they should be taking Semaglutide while breastfeeding. There is still no definitive data on the clinical use of Semaglutide for breastfeeding mothers. However, studies indicate that Semaglutide is only 0.4% to 1% orally absorbed and that its molecule is over 99% protein bound, making the amount in milk likely to be very low. It is best to err on the side of caution and consult your doctor before taking or resuming any Semaglutide medications while you are lactating.

Diabetes can affect breastfeeding, such as milk production levels or blood sugar
patterns, which presents a unique challenge. But with expert guidance from doctors and lactation consultants, there are ways for new mothers to prioritize their health without compromising that of their children.