Health Viewpoints

Tylenol’s Active Ingredient Acetaminophen Is Destroying Your Fertility: Peer-Reviewed Study

But that's not the only environmental toxin harming male sperm
BY Jennifer Margulis TIMEAugust 1, 2022 PRINT

Tylenol is destroying men’s sperm. That’s just one of the alarming revelations in a new article published in the peer-reviewed journal Environment International.

The study, “Combined exposures to bisphenols, polychlorinated dioxins, paracetamol, and phthalates as drivers of deteriorating sperm quality” was conducted by an international team of scientists from the United Kingdom and Denmark. [1]

These researchers studied urine samples taken in 2009 from 98 male volunteers who were between the ages of 18 and 30 at the time. They analyzed the urine for eight chemicals used in plastic production that are known to harm human fertility, including BPA, BPF, and BPS, as well as phthalates. These endocrine-disrupting chemicals can be found almost everywhere in today’s world, including clothing, baby diapers, food containers, and bedding material.

The researchers also analyzed urine samples for acetaminophen, also known as paracetamol, the active ingredient in more than 600 over-the-counter medications, including Tylenol and Panadol.

In addition, based on reports in the scientific literature, they estimated risks from a range of other plastic-related chemicals and a variety of common pesticides, including fungicides, herbicides, and insecticides.

From this, they came up with a hazard index, or risk measurement. This hazard index estimated the combined theoretical effect of combining several different toxins.

The results were not encouraging, though they may help to explain the rising levels of male infertility humans are experiencing in many places around the world. [2]

17 Times Levels Deemed Acceptable

Some of the urine analyzed showed that the combined exposure to the nine chemicals was more than 100 times higher than levels deemed acceptable.

But the average exposure to the chemicals was 17 times the acceptable levels.

“Tolerable exposures to substances associated with deteriorations of semen quality are exceeded by a large margin,” the scientists concluded. “Dedicated efforts towards lowering exposures to these substances are necessary to mitigate risks.”

Defective Sperm

As the researchers point out, the quality of male sperm and total sperm counts have declined sharply, particularly in Western countries.

There have also been what they describe as “alarming declines among healthy sperm donors in China.”

While it’s more difficult to assess sperm quantity and quality in non-Western countries, the researchers say, anecdotal and clinical evidence suggest men in developing countries may be struggling as well.

At the same time, there has been a rise in testicular cancer and reproductive abnormalities in the last few decades.

“Poor semen quality is part of a wider trend of deteriorating male reproductive health which has begun to escalate into a general fertility crisis,” the researchers explained.

The nine chemicals they tested for—as well as many others—are known to interfere with male fertility. In particular, these chemicals disrupt the development of male sex organs and interfere with male hormones.

An example that was referenced in the new study: When a team of scientists from Pakistan and Saudi Arabia exposed male rats to BPF, a chemical that is commonly found in plastic manufacture, they found that the chemical induced changes in the rats’ reproductive hormones and affected the shape and size of their testicles. This research, published in 2019 in the journal Environmental Health and Preventative Medicine, described this phenomenon as “BPF-induced testicular toxicity.” [3] 

Paracetamol or acetaminophen, the main ingredient in both Panadol and Tylenol, has been shown to disrupt prostaglandin signaling and InsL3 production (which is needed for the testicles to descend during gestation), according to the scientists. They cited research that shows that acetaminophen has been associated with a decrease in sperm production and quality in laboratory animals.

Though not mentioned in this present study, a 2017 review conducted by a team of scientists from Harvard and Duke Universities catalogued a growing body of scientific evidence implicating acetaminophen in brain anomalies, lung, and liver damage, among other health issues.

A more recent systemic review, published in the European Journal of Pediatrics in May of 2022, concludes that when accessing the safety of paracetamol, there is “mounting evidence in humans and in laboratory animals indicating that the drug is not safe for neurodevelopment.”

In addition, taking too much acetaminophen is the most common reason for acute liver failure in the United States, according to a 2009 study published in the journal Medical Clinics of North America. [4]

Cumulative Chemical Stress

Other recent science has shown that the COVID-19 vaccines reduce men’s sperm count and mobility.

While being over-exposed to any given chemical or medication known to affect fertility is problematic in itself, experts say that combining toxic exposures can have an even more pronounced negative effect on human health.

“The problem is that there are some things that we know are bad—pesticides and chemicals leeching out of plastics—and these combine with some things that most people think are safe, like acetaminophen and antibiotics, and cause additive chemical stress and damage to the human body,” said William Parker, Ph.D., a biochemist and CEO of WP Labs, a non-profit that looks at causes of immune disease in Western society, who was not involved in the study.

“It all combines and adds up to creates more chemical stress on our bodies,” Parker said.

Parker has co-authored several peer-reviewed articles about health issues associated with acetaminophen, which, he said, “is extremely bad for neurodevelopment.” His concern lies primarily with giving this pain killer to infants, babies, and toddlers.

In his most recent scientific paper, he and a team of scientists present 17 lines of evidence for how acetaminophen causes autism. [5]

“When you combine all this chemical stress plus this drug in babies and children, that’s when you can end up with permanent and often severe neurodevelopmental problems,” Parker said.

“There are multiple types of chemical interactions, sometimes they enhance each other, sometimes they cancel each other out,” said Dr. James Lyons-Weiler, Ph.D., who is the president and CEO of the Pennsylvania-based Institute of Pure and Applied Knowledge, a non-profit that conducts scientific research in the public interest, who was not involved in the study.

“There are insufficient studies about synergistic and anergistic interactions,” Lyons-Weiler continued. “With synergy you can expect more than an additive effect, with chemicals enhancing each other’s toxicities. There are other chemicals that can cancel each other’s negative effects—that’s anergy. But we have no idea what’s happening in the toxic soup.”

Lyons-Weiler, who teaches classes in environmental toxicology at, said reduction in sperm quality—no matter the complicated biochemical reasons—is a cause for concern. According to Lyons-Weiler, a study like this one is a positive step in the right direction, so we can better understand the impact of manmade chemicals on human health.

“We need studies that can actually test for interactions. That’s the most important science that can be done in toxicology today.”


[1] Andreas Kortenkamp, Martin Scholze, Sibylle Ermler, Lærke Priskorn, Niels Jørgensen, Anna-Maria Andersson, Hanne Frederiksen, “Combined exposures to bisphenols, polychlorinated dioxins, paracetamol, and phthalates as drivers of deteriorating semen quality,” Environment International, 2022, 107322, ISSN 0160-4120,

[2] “‘Remarkable’ decline in fertility rates,” BBC News. November 9, 2018. Accessed 06/14/2022.

[3] Ullah, A., Pirzada, M., Afsar, T. et al. Effect of bisphenol F, an analog of bisphenol A, on the reproductive functions of male rats. Environ Health Prev Med 24, 41 (2019).

[4] Fontana RJ. Acute liver failure including acetaminophen overdose. Med Clin North Am. 2008;92(4):761-viii. doi:10.1016/j.mcna.2008.03.005.

[5] Patel E, Jones JP 3rd, Bono-Lunn D, Kuchibhatla M, Palkar A, Cendejas Hernandez J, et al. The safety of pediatric use of paracetamol (acetaminophen): a narrative review of direct and indirect evidence. Minerva Pediatr 2022 Jul 13. DOI: 10.23736/S2724-5276.22.06932-4.

Views expressed in this article are the opinions of the author and do not necessarily reflect the views of The Epoch Times. Epoch Health welcomes professional discussion and friendly debate. To submit an opinion piece, please follow these guidelines and submit through our form here.

Jennifer Margulis, Ph.D., is an award-winning journalist and author of “Your Baby, Your Way: Taking Charge of Your Pregnancy, Childbirth, and Parenting Decisions for a Happier, Healthier Family.” A Fulbright awardee and mother of four, she has worked on a child survival campaign in West Africa, advocated for an end to child slavery in Pakistan on prime-time TV in France, and taught post-colonial literature to non-traditional students in inner-city Atlanta. Learn more about her at
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