How the Myth Began
Part 1 of a 3-Part Series
If the title of this blog caught your attention, sadly, that was the point.
Breast cancer is frightening—believe me, I know. According to the American Cancer Society, more than 40,000 women will die from breast cancer this year. And despite decades of research, we still do not fully understand what causes it.
That uncertainty leaves people wanting clear answers. When a disease feels unpredictable, the idea of a simple cause—and a simple way to avoid it—can be appealing. So when someone claims to have found a cause, any cause, it’s understandable that people pay attention.
But according to the Breast Cancer Research Foundation, “No credible scientific evidence has linked the use of deodorant and breast cancer risk. While social media posts and internet rumors warn of ‘carcinogenic’ ingredients lurking in antiperspirants, high-quality research doesn’t back up those claims.”
Yet the rumor continues to circulate.
Why I Decided to Write About This
A customer sent me a link to another company selling natural deodorant. Their page claimed that using natural deodorant could help prevent breast cancer. She suggested that if I warned customers about the supposed link between antiperspirants and breast cancer, I would probably sell a lot more products.
Sadly, she may be right.
I started Chagrin Valley Soap & Salve out of a genuine concern about the number of synthetic chemicals used in commercial skincare and the possible effects those ingredients may have on our health and on our planet.
I believe deeply in using natural products.
But when I read the page she shared, I wasn’t frightened by the claims themselves — I was frightened by the scare tactics being used to sell a product.
As a breast cancer survivor, I felt angry — and honestly, a bit betrayed. Fear about a disease this serious should never be used as a marketing tool.
When and How Did the Antiperspirant Myth Begin?
The rumor linking antiperspirants to breast cancer appears to have started with viral chain emails that began circulating widely in the late 1990s.
Chain emails from that era weren’t archived the way web pages are today. They were forwarded from person to person, often edited, reworded, or expanded along the way. As a result, there isn’t a single original version of the message—just many variations that repeated the same basic claims.
Despite the differences in wording, most versions of the email shared the same alarming idea: that antiperspirants cause breast cancer by blocking the body’s ability to release toxins through sweat.
Most versions of the message included several key claims:
Antiperspirants “prevent the body from purging toxins.”
The email claimed that by blocking sweat, antiperspirants stop the body from eliminating harmful toxins, and these toxins accumulate in lymph nodes or breast tissue rather than leaving the body.
Most breast cancers occur in the upper‑outer quadrant of the breast, near the underarm.
Because lymph nodes are located there, the email claimed this was “proof” that antiperspirants block toxins and cause cancer to develop in that area.
Men rarely develop breast cancer.
The reasoning in the email was that because antiperspirants get trapped in men's underarm hair, it never reaches the skin.
Shaving the underarms increases absorption of toxins.
It warned that small nicks from shaving allowed the substances from antiperspirants to enter the lymph nodes under the arm.
This buildup was said to cause breast cancer.
Readers were urged to stop using antiperspirants, and like many chain messages of the time, it encouraged people to share the warning widely with friends and family.
Why This Topic Deserves a Closer Look
The internet can connect us with extraordinary knowledge and valuable research, but it can spread misinformation just as quickly.
Although no one knows who started the rumor linking antiperspirants to breast cancer, versions of the claim have appeared on countless blogs and websites over the years — including some that sell natural deodorants.
When it comes to health concerns, it’s understandable that people assume something must be true if they see it online. These chain emails and posts often sound convincing because they mix small pieces of truth with ideas that aren’t supported by scientific evidence.
There is so much misinformation wrapped into this rumor that it would be impossible to address it all in a single article.
So this post is the first in a three‑part series. In the next articles, we will look more closely at the claims made in that original email and explore what scientific research actually says about antiperspirants, deodorants, and breast cancer.
This article was originally written in 2015 and has been reviewed and updated for clarity.
