*THIS* Happens After Long Term Use of Antiperspirants
- Madame Sweat | Hygiene Educator · Product Developer for Kaia Naturals
Armpits have been described by scientists as a “rainforest” of bacteria. Most of us grew up being told to use antiperspirant to combat the odor associated with this issue, but in the long run it may actually make you smell worse. Read on to learn the side effects of antiperspirants.
Long-term antiperspirant use doesn't just block sweat — it changes which bacteria live in your armpit. Research shows antiperspirant users develop more diverse, and smellier, bacterial communities than deodorant users or people who use nothing at all. That's why switching off antiperspirant often comes with a temporary odor spike: your armpit's bacteria has to rebalance, which typically takes several weeks — not because natural deodorant "doesn't work."
Key takeaways:
- A study at the NC Museum of Natural Sciences found antiperspirant users develop more diverse, smellier bacteria (Corynebacteria) once they stop using product than deodorant users or non-users
- Aluminum chloride in antiperspirant blocks sweat glands and suppresses Staphylococcaceae, the "good" bacteria that normally keeps odor in check
- The resulting odor spike after quitting antiperspirant is temporary — bacteria typically rebalances within several weeks
- A shower-first, bacteria-targeting routine (not a stronger deodorant) shortens and manages this transition period
Antiperspirant Causes MORE Odor-Causing Bacteria
Antiperspirant is classified as an over-the-counter drug in both Canada and the U.S. because it uses aluminum chloride that blocks your sweat glands to prevent you from perspiring. Read more about aluminum here. Your body becomes reliant on antiperspirant. If you stop using it, you can experience major changes in the bacteria that grows under your arms, causing you to smell. There is a reason it is classified as an over-the-counter drug, your body becomes dependent on it.
The “Rainforest” of Bacteria Under the Arms
In a study conducted at the NC Museum of Natural Sciences’ Genomics & Microbiology Lab, 18 subjects were recruited to compare what happens to bacteria under your armpits when you switch the type of underarm products you use. The subjects were divided into three groups: (1) people who used antiperspirant daily, (2) people who used deodorant daily and (3) those that did not use any underarm products. Every day of the study, both armpits were swabbed and the bacteria was analyzed.
After two days, the antiperspirant-users started to develop diverse bacteria under their arms. By the fifth day, there was significant growth of bacteria – in some cases, it was a pungent type of bacteria called Corynebacteria, the smelliest of all bacterial flora.
There are two main types of bacteria in your armpits:
Corynebacteria – The type that makes you smell
Staphlococcaceae – The least smelly bacteria
What Happens To Your Body When You Stop Using Antiperspirant?
Ultimately, antiperspirant users experienced the most drastic change in bacterial communities when they stopped using any products. At the end of the study it was found that there was an initial increase of smelly bacteria in the underarms of antiperspirant users. Using antiperspirant reduces the amount of staphlococcaceae bacteria (the least smelly) that grows under the arms. This creates more opportunities for odor-causing species to develop.
Deodorant users did not experience the same increase in odor-causing bacteria when they stopped using underarm products. They even had fewer species of bacteria in their armpits compared to armpits of participants who use no product at all.
It Won’t Last Forever
The study unveils that long term use of antiperspirant actually creates more bacteria on your armpits once you stop using them.
If you are an antiperspirant user making the switch to natural deodorant, it is important to know that this odor-causing bacteria won’t last forever, it is just a part of the detox that happens when you discontinue use.
I believe that our consumers should understand what is happening to their body during The Stages of Detox. It can be discouraging when it feels like natural deodorant isn’t working. Basically, your body becomes addicted to antiperspirant and it is harder for it to go without it. Thankfully, after several weeks, the culture of bacteria is able to rebalance and stop overproducing odor-causing bacteria.
THE SYSTEM BUILT FOR THIS EXACT TRANSITION
Knowing why this happens is one thing. Getting through it comfortably is another. The transition period is shorter and easier to manage with the right routine, not a stronger natural deodorant, but a shower step that addresses the bacteria directly, plus support for the extra moisture your body produces while it re-adjusts to sweating normally again.
This is exactly what the 3-Step System for Excess Odor and Sweat was built for. The Underarm Bar (activated charcoal and apple cider vinegar) targets the bacterial overgrowth in the shower, before deodorant goes on. The Charcoal Deodorant absorbs odor throughout the day without blocking pores the way antiperspirant does. The Sweat Powder manages the extra moisture that shows up as your sweat glands reopen, completely normal, and temporary.
Used together during the detox window, this system addresses both things the study above describes, the bacteria shift and the moisture increase, instead of leaving you to wait it out with a product that isn't built for this specific stage.
The 3-Step System for Excess Odor and Sweat →
FREQUENTLY ASKED QUESTIONS
Is it normal for armpits to smell worse after quitting antiperspirant?
Yes. Antiperspirant use suppresses the least-smelly bacteria strain, so when you stop, other odor-causing bacteria multiply before your armpit's microbiome rebalances.
How long does the antiperspirant detox period last?
Typically several weeks, though it varies by body chemistry — some people adjust within days, others take closer to a month.
Is antiperspirant actually classified as a drug?
Yes — in both Canada and the U.S., antiperspirant is classified as an over-the-counter drug because it uses aluminum chloride to physically block sweat glands.
What can I do to make the switch easier?
A shower-first routine that targets the bacteria directly, plus a powder to manage extra moisture, shortens the adjustment period more than switching deodorants alone.