There’s no proof that Mucinex helps people get pregnant

Many people worldwide struggle with infertility, with estimates suggesting that approximately one in every six people of reproductive age experience the condition in their lifetime.

Some people online, including Alexa Lemieux from the reality TV show “Love Is Blind,” have suggested that taking Mucinex may improve people’s chances of conceiving.

Lemieux said in a viral TikTok posted in March 2024 she went through two failed rounds of intrauterine insemination (IUI) treatment before trying Mucinex. She also took an estrogen-lowering medication called letrozole that was left over from her treatment.  

“During my ovulation, I took Mucinex and a few weeks later found out that I was pregnant,” she said.

VERIFY dug into the existing research to find out whether Mucinex is scientifically proven to help people get pregnant. 

THE QUESTION

Is Mucinex scientifically proven to help people get pregnant?

THE SOURCES

• The Cleveland Clinic
• England’s National Health Service
• 1982 study titled “Improvement of cervical factor with guaifenesin”
• Merck Manual article written by Robert Rebar, M.D., a reproductive endocrinology and fertility specialist
• Article for GoodRx Health written by pharmacist Kevin Le
• Shahin Ghadir, M.D., board-certified reproductive endocrinologist and infertility specialist
• Armando Hernandez-Rey, M.D., board-certified reproductive endocrinologist and infertility specialist
• Lora Shahine, MD., board-certified reproductive endocrinologist and infertility specialist

THE ANSWER

No, Mucinex is not scientifically proven to help people get pregnant. 

WHAT WE FOUND

Mucinex is not scientifically proven to increase a person’s fertility and help them get pregnant. But doctors say there’s generally no harm in taking the medication while trying to conceive due to the low risk of serious side effects. 

Guaifenesin, the active ingredient in Mucinex, works to thin the mucus or phlegm in a person’s lungs. The theory is that Mucinex could increase a person’s fertility by thinning another type of mucus in the body – cervical mucus. 

But “there is no evidence that using medications to thin the mucus (eg, guaifenesin) improves fertility,” Robert Rebar, M.D., a reproductive endocrinology and fertility specialist, said in an article published by Merck Manual. 

When a person is ovulating, mucus in the cervix becomes thinner so sperm can go through it more easily, according to England’s National Health Service (NHS).

In some cases, a person’s cervical mucus may be too thick, making it harder for them to conceive, Shahin Ghadir, M.D., a reproductive endocrinologist, explained. 

While it’s possible that Mucinex could thin cervical mucus for some people, the drug’s fertility benefits are “questionable,” reproductive endocrinologist Armando Hernandez-Rey, M.D., told VERIFY. Most of the pregnancies that people have reported on social media after using Mucinex can be “chalked up to coincidence,” he added. 

Some people, like Lemieux, also take letrozole or other medications used to treat fertility issues in tandem with Mucinex. So it’s unclear whether the fertility medication, Mucinex, a combination of both or none of the above may have helped to improve the person’s fertility.

RELATED: No, birth control does not cause infertility

Our experts say the link between taking Mucinex and improved fertility stems from a small study published more than 40 years ago. 

That 1982 study involved 40 couples who were unable to conceive for at least 10 months. Tests suggested that “hostile,” or poor, cervical mucus rather than defective sperm production could be the cause of the couples’ infertility.

Each female participant took 200 milligrams of guaifenesin orally three times daily from day five of her monthly cycle when her temperature started to rise around the time of ovulation, according to the study. More than half of the female participants saw a marked improvement in the quality of their cervical mucus and 40% became pregnant after taking Mucinex.

But experts caution against relying on this study as proof that taking Mucinex increases a person’s fertility and helps them get pregnant. 

Reproductive endocrinologist Lora Shahine, MD., told VERIFY partner station WTHR that the “very small study” was “not well-designed.”

In an article for GoodRx Health, pharmacist Kevin Le writes that the study did not have a “comparison group,” or a group of participants who did not take Mucinex.

“Without a comparison group, it’s hard to know if Mucinex is the reason some female participants became pregnant,” Le said. 

There is “no proven, acceptable study” that shows taking Mucinex leads to improved fertility, Ghadir added.

A spokesperson for Reckitt, the company that makes Mucinex, also told WTHR that Mucinex should “only be used as intended and in line with usage instructions.” They added that “taking Mucinex for infertility constitutes off-label use.”

Guaifenesin, or Mucinex, is often combined with other medications used to address cold and flu symptoms, such as the nasal decongestant pseudoephedrine, the Reckitt spokesperson said. Pseudoephedrine should “only be used for approved indications and carries specific risks,” they added.

In other words, you shouldn’t take pseudoephedrine if you aren’t experiencing nasal congestion. 

“Taking medications outside their approved indications or without acknowledging all active ingredients may be harmful,” the Reckitt spokesperson said. 

However, doctors say the risks of taking Mucinex alone while trying to get pregnant are generally low since the medication usually does not cause serious side effects. 

"Some people will have nausea, some people will have headaches, but it's pretty rare," Shahine told WTHR. 

People who are experiencing infertility and want to try taking Mucinex should always consult their doctor beforehand. Your provider may also recommend other medications and medical procedures that are scientifically proven to promote fertility.

WTHR reporter Allison Gormly contributed to this report.