If you’re among the 1 in 6 people worldwide who’ve struggled to get pregnant, you’ve likely tried at least a couple tactics to “boost” your fertility—tracking ovulation, maybe, or tweaking your exercise routine.

Then there’s the abundance of fertility “tips” on TikTok, from drinking okra water to avoiding hip thrusts to the one that keeps resurfacing: taking Mucinex to get pregnant. Yup, Mucinex, as in the cold and flu medicine.

Some creators are sharing positive pregnancy tests after trying the “Mucinex method.” If you’re willing to try anything to get pregnant, they say, “you have to try [Mucinex].”

While that’s great for them, is this “hack” one that will work for everyone experiencing fertility challenges? Well+Good asked an OB-GYN and fertility expert for their insights into the truth behind the claims.

Mucinex *does* have potential benefits

Admittedly, the link between Mucinex and pregnancy makes more sense—or at least seems less random—when doctors explain the science.

“The theory is that guaifenesin (the active ingredient in Mucinex) will thin cervical mucus to improve the ability for sperm to pass through the cervix to reach the egg,” says Suzy Lipinski, MD, a board-certified OB/GYN and medical director at Pediatrix Medical Group.

This isn’t very far-fetched, considering guaifenesin thins mucus in other areas of the body, making it easier to clear the stuff out of your nose and throat. And it’s also true that swimmable cervical mucus is a key aspect of fertility.

“Cervical mucus around the time of ovulation becomes wet and slippery. The consistency of this type of discharge helps sperm swim to an egg at the time of ovulation,” explains Rachel McConnell, MD, a fertility expert with Columbia University Fertility Center.

She points to a small 1982 study in Fertility and Sterility¹ that actually researched guaifenesin’s effect on cervical mucus. The research included 40 couples who had struggled to get pregnant for at least 10 months, possibly because of “hostile” cervical mucus. Each woman was given 200 mg of guaifenesin three times daily from day five of her menstrual cycle until a rise in biphasic basal body temperature (which signals ovulation). In the end, 23 women had a marked improvement in their cervical mucus quality, and 15 of those women became pregnant.

Of the 15, participants whose infertility was credited only to too-thick cervical mucus became pregnant within about two months on average, while those who had additional fertility problems got pregnant within about five months.

But it’s also *not* a miracle fertility pill

It’s important to note that, promising as it seems, the Fertility and Sterility study has its flaws. It’s more than 40 years old at this point, for one, and it also only looked at a very small number of people. Plus, there was no “control” group to compare the results against.

Likely due to this lack of quality research: “The makers of Mucinex have very clearly stated that this is not a studied use of the medication and it is not recommended,” Dr. Lipinski says.

Still, if thick mucus is the fertility issue at hand, Mucinex may help some people who are trying to conceive—especially with the help of best practices. “It is best to use Mucinex about five days prior to expected ovulation and continue it only through the ovulation day,” Dr. McConnell advises. “However, patients must see their fertility doctor to determine if Mucinex may be beneficial in their case.”

It’s crucial to know the potential risks, too, especially if you do get pregnant. According to the American Academy of Family Physicians, guaifenesin “might be unsafe” during the first trimester. Some studies also suggest there’s an increased risk of birth defects, but really, we don’t have enough research to know for sure.

You’ll also want to be cautious if you’re breastfeeding, chestfeeding, or lactating, because some versions of Mucinex might affect your milk supply. “If taking Mucinex, it must be Mucinex plain (with only guaifenesin),” Dr. McConnell says. “Similar expectorants would not be advised due to most containing other ingredients such as dextromethorphan [like Mucinex DM] or pseudoephedrine [like Mucinex D], which cause a drying effect.”

The bottom line

Whether or not Mucinex really helps with pregnancy is up in the air. While it could thin cervical mucus and help sperm get to an egg, this hasn’t been adequately studied and isn’t recommended or FDA-approved. Rather, Dr. McConnell says, it’s used off-label for pregnancy and its benefits are anecdotal.

For its part, Reckitt (the company that makes Mucinex) says it’s aware of the social media claims around Mucinex and fertility. “It is important that we clarify that Mucinex should only be used as intended in line with label directions. Taking Mucinex for infertility constitutes off-label use,” Reckitt told Well+Good in an email statement. “Taking any medications outside their approved indications or without acknowledging all active ingredients may be harmful. In case of doubt, we recommend women have a discussion with their healthcare professional.”

So what can you do? Other than staying hydrated and scheduling sex around ovulation, seeing a specialist is a great idea—but at what point?

According to Dr. Lipinski, it depends on the situation. “If a couple has tried for one year without a pregnancy, then they should see a doctor for evaluation,” she recommends. “If the woman is over 35 years of age, then seek evaluation after six months of trying.”

Dr. McConnell also encourages paying attention to what your cervical mucus looks like. “As the fertile window is entered, cervical mucus will increase and the consistency and color become similar to egg whites,” she says. “If clear, watery cervical mucus is not noted mid-cycle and you are trying to conceive, this would be a good time to discuss findings with your fertility doctor.”

—reviewed by Andrea Braden, MD, OB/GYN