After finishing chemo for breast cancer and noticing that I had no body odor, I decided to write a post about it because the Internet was silent on the topic. Apparently, I wasn’t the only one who’d come up empty. A number of you commented that you’d noticed the same thing and similarly found no explanation.
Well, five years after my initial diagnosis, maybe 4.5 years after finishing chemo, I still can’t locate info on the Internet about this.
If I do find the odd article about cancer and body odor, it’s about the exact opposite: smelling bad as a result of the disease or certain medications. Not what I’m looking for.

It is quite weird that I can’t even find anything in the US National Institutes of Health PubMed database, so I would suspect that chemo-related loss of body odor is not on the radar of researchers. Well, it’s certainly not on my oncologist’s radar because he said he’d never heard of it and didn’t think it could be attributed to chemotherapy. Personally, I can’t imagine how it could be from anything else.
I’m going to pester him about it again during my next appointment. Usually armput odors are caused by bacteria. As an article from the Cleveland Clinic explains, odor is produced “when bacteria on the skin break down acids contained in the sweat produced by apocrine glands, which are located in the armpits, breasts, and genital-anal area. The bacteria’s waste products are what produce the smell.”
And NPR ran a story on researchers looking into what the worst bacterial offenders are, noting, “When the bacteria break down the sweat they form products called thioalcohols, which have scents comparable to sulfur, onions or meat.” The greatest culprit? Staphylococcus hominis.
So then maybe the chemo stops the production of thioalcohols? Or chemo wipes out the S. hominis living on our skin? I’m surprised that no one is researching this in the context of chemo patients, because it seems like it might have some health implications. We still don’t know all the side effects of chemo drugs and it would be useful to start a conversation about this one.
If you’re experiencing this, please tell your medical team. They might simply not be aware of what’s happening.

And you might be wondering what my current experience is, almost five years later. Even though I departed the realm of the completely-odorless about two years after completing chemo, I still have very little body odor. And it’s not like I don’t give it chances to fester since I work up a good sweat when I exercise. Note that my left armpit, which was thoroughly irradiated, exudes almost no noticible odor. My right armpit doesn’t smell very much, but sweat that gets on, say, a sports bra will start making the fabric stink the next day. (Let’s just say that I’ve been testing this out.) The skin in the armpit itself? Minimally, and that’s with no deodorant, although I do wear it anyway.
Certainly, the six weeks of radiation therapy on my left side would likely have an effect, and so it would make sense that there’s a difference in odor between both armpits.
Still, the “natural” (and unfortunately overpriced – yeesh!) deodorants do a very good job of fragrancing my armpits because they don’t have to work very hard.
So the mystery remains. I’m going to keep digging into this as it’s likely there’s a disruption of our skin microbiome involved, and given the popularity of that research (see microbiome and armpit odor info at drarmpit.com), someone may be looking into the connection between chemo and body odor in the future. Until then, I’ll just remain happy and relatively unstinky with fingers crossed that it continues.
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Many thanks to my very patient husband who played along and agreed to smell every place I pointed to. I’ll revisit the odor issue during the summer just in case…