Unless you’re having—or have had—a baby, it’s very possible you’ve never heard of a pretty incredible substance called colostrum. The earliest breastmilk people produce, this golden liquid (often referred to as “liquid gold”) is a newborn baby’s first food—and it’s a seriously impressive one at that. Not only does colostrum protect brand-new babes’ digestive systems and provide them with the exact nutrition they need to thrive, but it also helps them build an iron-tough immune system. 

“Colostrum is nutrient-dense and rich in antibodies and antioxidants,” explains The Vitamin Shoppe nutritionist Roseanne Schnell, C.D.N. “The nutrients it contains include immunoglobulins (antibodies), lactoferrin (protein with immunological properties), leukocytes (white blood cells), growth factors, carotenoids (antioxidants like vitamin A), magnesium, copper, zinc, and digestive enzymes. Together, they support a baby’s immunity, gut and digestive health, cellular growth, vision, and skin, heart, and bones.”

Interestingly, humans aren’t the only mammals that produce colostrum—and teeny tiny humans aren’t the only ones who can benefit from the stuff. In fact, bovine colostrum (yep, that means colostrum from cows) is an increasingly popular supplement—and given its immune benefits, one you might just want to add to your routine, particularly during cold and flu season. 

The Bovine Colostrum Basics

The colostrum you’ll find in supplements comes from cows, and it’s harvested by the same people responsible for the gallons and gallons of milk you’ll find at your local grocery store. Like the colostrum human mothers produce, it contains antibodies, digestive enzymes, vitamins, and minerals.

“Bovine colostrum is almost identical to human colostrum regarding its beneficial compounds,” Schnell explains. “It’s also easy to obtain in large quantities to be pasteurized, dried, and put into pills or powdered supplements.”

Colostrum’s Benefits

While colostrum has been studied for its impact on a variety of different aspects of health, there are two that make it especially beneficial during the colder months, when all sorts of bugs circulate and threaten to leave us curled up on the couch for days on end: gut health and immunity (which, in case you haven’t heard by now, are very much interconnected).

Read More: 6 Things We Do That Mess With Our Gut Microbiome

When it comes to the gut, “the immune factors and growth factors in colostrum may support the growth of intestinal cells, and strengthen the gut wall and the integrity of the intestinal lining,” Schnell explains. This supports your gut’s ability to keep potentially problematic substances from hitting your bloodstream and promotes overall digestive health, especially in people who struggle with gut issues.

Meanwhile, “the lactoferrin and antibodies (IgA and IgG) found in colostrum play a role in the immune system’s response to bacteria and viruses,” adds Schnell. For this reason, it’s become a popular supplement to incorporate when you’re feeling under the weather.

Considering those two areas of impact, you can see why colostrum would be hailed as a must-have for cold and flu season, when fortifying our immune system is top-of-mind for most of us. Research suggests it really is worthwhile, too. One study that looked at the impact of supplementing with colostrum for three months throughout flu season found that those who made colostrum a part of their daily immune health routine fared better through that time of year than those who didn’t.

Trying Colostrum For Yourself

Suddenly, this milky substance sounds pretty appealing, doesn’t it? If dairy is a part of your diet, colostrum is definitely a handy supplement to have in your pantry—especially throughout cold and flu season.  

Of course, since colostrum is made from dairy, people with lactose intolerance or a milk or milk protein allergy will probably need to steer clear, says Schnell. And since we don’t have data on whether it’s safe for pregnant or breastfeeding women to supplement with colostrum, Schnell advises they hold off on trying the milky superfood. 

Read More: Raise Your Hand If You Have Trouble Digesting Dairy

Additionally, as with any dairy product, the sourcing of your colostrum supplement matters! Purchasing from a reputable company is an absolute must. “Look for supplements from companies that do quality testing and manufacture their products with bovine colostrum from cows that are under close supervision for proper treatment and no exposure to antibiotics, pesticides, or synthetic hormones,” Schnell urges. This information should be clearly highlighted on the product’s packaging. 

Should you decide to give colostrum a go this flu season, take note that the general recommended amount is 500 milligrams once per day, according to Schnell. Some colostrum products stand out from the crowd by concentrating the percentage of immunoglobulins they offer, as well as ensuring their colostrum offers specific types of growth factors. A quick example: The Vitamin Shoppe brand Colostrum features 40 percent immunoglobulins G (IgG), a type of antibody the immune system produces to fight germs.