Can Mucinex really help you get pregnant?

You've probably seen the viral trend: women who claim they struggled with infertility for years, took Mucinex to help them cope with a cold or COVID, and boom! Suddenly they're pregnant. Unfortunately, there's not good evidence that Mucinex, or any cough syrup for that matter, can help you conceive. Here's what you need to know.

Where did the theory surrounding Mucinex and pregnancy come from?

This comes, believe it or not, from a study published 40 years ago in the journal Fertility & Sterility. Researchers looked at 40 couples who had struggled with infertility for at least ten months. Each woman was given guaifenesin – one of the active ingredients in Mucinex – three times a day from day five of the start of her period until she showed a rise in her basal body temperature to indicate ovulation.

Then the couples underwent post-coital testing, which means doctors checked to see how well their partner's sperm responded to their cervical mucus. Of the 23 patients who had "marked improvement," 15, or about two-thirds, became pregnant. Women whose infertility appeared tied to their cervical mucus got pregnant on average within 2.4 months, while women with additional fertility problems became pregnant on average within about 5.6 months.

What is guaifenesin?

Guaifensin is the over-the-counter ingredient in cough syrups such as Mucinex that is theorized to help with fertility. It's been around since the 1950s and has long been used to treat cough, to loosen phlegm and expel it from your lungs. It works to thin out mucus and make it less sticky. As a result, it makes it easier for your lungs to get rid of it, and it changes a dry, unproductive cough to one that's more productive and less frequent. Since it works on all the mucus in your body, the theory is that it can make your cervical mucus more liquid-y, too.

Can taking Mucinex or other cough syrups really help you get pregnant?

Probably not. There's really not much evidence to justify its use for this purpose. Proponents claim that it may help you get pregnant by making your cervical fluid wetter and more slippery, which makes it easier for sperm to travel through your cervix to fertilize an egg. But other than the 1982 study, there isn't any research to support this.

A 2011 case report published in the International Journal of General Medicine found that guaifenesin increased sperm counts and motility in a 32-year-old man who took 600 mg twice daily for two months. But that's just one person. There aren't any well designed studies to show it actually works.

Safe ways to use Mucinex or other cough syrups when trying to get pregnant

If you want to use Mucinex or another cough syrup to try to get pregnant, talk to your provider first. They can advise you on whether or not they recommend it, and if they do, what dosage to use. Just keep in mind there's not enough research to show it helps fertility. In addition, like any medication, Mucinex (guifenisen) has side effects. You could experience dizziness, drowsiness, headache, nausea, abdominal pain and/or vomiting when taking it.

Instead of recommending cough medicine, your doctors will likely recommend that you take the following steps to help boost your fertility:

• Maintain a healthy weight. Up to twelve percent of all infertility cases are due to the woman being overweight or underweight, according to the American Society of Reproductive Medicine. Be sure to talk with your provider about ways to stay at a healthy weight while trying to conceive. 
• Don't smoke. Up to thirteen percent of cases of female infertility are caused by cigarette smoking. If you do smoke, see your provider to learn how to quit. They can help you come up a plan that works with your lifestyle and fertility goals.
• Eat a healthy diet. One study, known as the Nurses' Health Study II, found that a "fertility diet" that was rich in monounsaturated fats, vegetable sources of protein, dairy and low-glycemic carbohydrates was associated with a lower risk of infertility. And it's always a good idea to eat healthily. Doing so has lots of additional health benefits, like lowering cholesterol, blood pressure, and stress levels – all good things to have in check before TTC.

Learn other ways to prepare for getting pregnant here.