Mucinex contains the active ingredient guaifenesin, which is thought to thin out cervical mucous and help women get pregnant, though there is no clinical data to support this theory
Women taking a common over-the-counter cold medication are being warned it could get them unexpectedly pregnant.
Doctors say there is anecdotal evidence taking Mucinex makes it easier for sperm to travel through the vagina and reach the egg.
Social media and forums are full of women who claim they conceived while taking the $1 pill after years of struggling with fertility.
The theory is that because the drug works by thinning phlegm, it may also thing mucus in the cervix, creating a smoother route for sperm to reach an egg.
However, doctors warn Mucinex can cause vomiting, dizziness and headaches in rare cases at high doses.
A woman in a viral TikTok video claimed she had been ‘trying to conceive for years’ and ‘doing anything and everything’ to get pregnant but was unsuccessful until she took a decongestant drug containing guaifenesin, the active ingredient in Mucinex.
User @cassiemadams posted a video stating: ‘Trying to conceive for years just to take Mucinex and get pregnant. [I don’t know] what kind of magic [is] in those pills but here we are.’
But while Cassie was happy to get pregnant, there were plenty of users who commented they were ‘never taking Mucinex again’ in case it caused an unwanted pregnancy.
A reproductive expert told DailyMail.com there is no hard evidence that Mucinex or guaifenesin raises the chance of conceiving, but there were plenty of indirect evidence.
Dr Karen Tang, a gynecological surgeon in Pennsylvania, posted a video explaining the theory behind guaifenesin and increased fertility, saying the ingredient is meant to loosen the mucus people get when they are sick, which makes it easier to cough it up.
This has led people to question whether the ingredient could make cervical mucous thinner, which would allow sperm to more easily travel to reach a woman’s egg, fertilize it and produce a pregnancy.
Dr Rachel McConnell from Columbia University’s Fertility Center told DailyMail.com cervical mucous around the time of ovulation, when a woman is most fertile, becomes thinner and ‘slippery,’ which helps sperm travel.
Because guaifenesin thins out mucous in the respiratory tract, the theory is that women who have thick cervical mucous may find guaifenesin also thins out that mucous.
Dr McConnell added: ‘Mucinex may be useful for women who are known to have thick cervical mucus as the only cause of their infertility. However, patients must see their fertility doctor to determine if Mucinex may be beneficial in their case.’
TikTok user @cassiemadams said in a video she and her partner had been trying ‘anything and everything’ to get pregnant but were unsuccessful until she took guaifenesin
The idea that guaifenesin can increase the chance of pregnancy has been around a long time, but the only study to be conducted on it was done in 1982.
Researchers observed 40 couples who were having trouble conceiving after 10 months. Researchers took samples of cervical mucous from the women before and after taking guaifenesin.
Twenty-three couples saw an improvement in the ‘quality’ of the cervical mucous and 15 of those couples successfully conceived. However, Dr Tang noted there was no control group in the study to compare the guaifenesin group to.
With 2million views, hundreds of people have commented on Cassie’s video, sharing similar stories.
User Ahzbah commented: ‘5 years no protection, both got sick bad one week and took Mucinex. Have a happy 7 month old now.’
Another, SunshineRnbwSkttlz23, said: ‘PCOS and tried multiple fertility treatments for years…try Mucinex once and BOOM! 7 months pregnant.’
And while some welcomed the news, others said their pregnancies were unplanned because of the medication.
TikToker Marcia Hofer commented: ‘My Mucinex baby turned one in December, except we weren’t trying. I just had a cold.’
Ellie Bagwell claimed she got pregnant while taking Mucinex even though she was on birth control.
While another added: ‘I got sick and now I have a one year old. They should definitely put that in the warning label!’
One commenter called herself ‘a victim of Mucinex’ while another said she got pregnant ‘except trying NOT TO.’
And others swore off the drug out of fear they too could unexpectedly get pregnant.
One person commented that she was currently sick and taking Mucinex: ‘Don’t scare me like that.’
Mariska Alexus said: ‘Wow that’s my go to medicine too… goodbye forever Mucinex.’
In one TikTok video, Cassie said she took the generic version of Mucinex bought at Target that contained the same active ingredient, guaifenesin.
And Kalico Mermaid expressed her fear: ‘Stop – I’m in between [birth control] refills and I’ve been taking Mucinex because I’ve been sick too. Y’all are scaring me.’
In a separate video, Cassie said she took the generic version of Mucinex bought at Target.
While not the name brand Mucinex itself, the store-brand version contains the same active ingredient, guaifenesin.
She said she took one pill every 12 hours of the extended release version.
In a third video, Cassie explained she took the medication for five days, beginning a few days after her menstrual cycle ended.
She added she and her partner were ‘doing anything and everything’ to conceive.
Cassie said: ‘I believe that that worked. There were only a few things that we changed this last go around.’
While Cassie did not detail any side effects she may have experienced, common side effects of guaifenesin include headache, rash, nausea and vomiting, diarrhea and trouble sleeping.
More recently, there was a 2010 case study of a 32-year-old male being evaluated for infertility. His doctor prescribed him guaifenesin. Two months later, a semen analysis showed significant improvement in his sperm count and motility.
The authors wrote: ‘Evidence for the effectiveness of guaifenesin is almost entirely anecdotal. Given the mechanism of action of guaifenesin, it is not clear from this case why the patient demonstrated such a large improvement in both sperm count and motility.’
They called for further research into the matter.
Reckitt, the manufacturer of Mucinex told Good Morning America: ‘Reckitt is aware of recent social media activity surrounding Mucinex and fertility, and we understand why there is heightened interest in this topic.
‘As a global leader in health and hygiene, 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.
‘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.
‘Please always read the label and safety information before taking any self-care medication.’
