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Is Your Aluminum Antiperspirant Setting You Up for Smellier Armpits?

If you are like most people you use an aluminum antiperspirant daily. What happens if you stop? Body odor, right? Now there's an explanation.

People take their aluminum antiperspirant for granted. They apply it every morning like clockwork because of a fear of body odor. No one wants to offend co-workers, friends or family members. That’s especially true when it’s hot and humid. Who would have guessed that an aluminum-containing antiperspirant might change the ecology of underarm bacteria and set you up for even smellier armpits?

The “Bugs” On Your Skin:

Most of us grew up thinking that germs were bad and antibiotics that killed bacteria were good. We were told that we needed to disinfect everything from kitchen counters and toothbrushes to our hands and our mouths.

We now know that advice was probably misinformed. Listen to our interview with gastroenterologist Robynne Chutkan, MD, (radio show # 1078) to understand why!

We rarely consider that our skin, and especially our armpits, are absolutely loaded with living organisms. A fascinating article in the journal PeerJ (Feb. 2, 2016) describes it this way:

“Like the gut or the mouth, the human skin is covered with life. This life includes bacteria, fungi, Archaeans, bacteriophages, and even animals such as nematodes and Demodex mites. Since the 1950s it has been clear that the precise composition of the skin biome influences its effectiveness as a defensive layer against pathogens, and contributes to bodily odors. Some species are better at defending our skin than others, just as some species produce different odors than do others. What is unclear is the extent to which human behaviors influence the composition of skin microbes.”

These scientists point out that aluminum antiperspirant and deodorant products are used by up to 90% of Americans. They go on to describe how such products can alter the balance of microbes living in our armpits.

What’s Living in Your Armpits?

It turns out that the area of our underarms is an ideal environment for a variety of bacteria. Some of the most common fellow travelers include:


There is also tremendous variability in armpit bacteria from one person to the next. In other words, some people have lots of smelly bacteria while others have less of those kinds of microbes. This “biomass bacterial community” is strongly influenced by our use of personal hygiene products.

What The Researchers Did:

In this study 18 “citizen scientists” were recruited and tested for bacteria in their armpits. There were three groups.

  1. One group did not use antiperspirants or deodorants (3 men & 2 women)
  2. One group regularly used deodorants (3 men & 2 women)
  3. The third group regularly used aluminum-containing antiperspirants (3 men & 4 women)
  • Day 1: Follow standard behavior
  • Days 2-6: If applying antiperspirants/deodorants, discontinue use.
  • Days 7-8: All participants (including those not used to using personal hygiene products on their underarms) used aluminum antiperspirant. The investigators provided Secret Powder Fresh to the women and Old Spice Fiji to the men. These products contained the active ingredient aluminum zirconium trichlorohydrex Gly.

On each day of the experiment the underarms of these study subjects were rubbed for 45 to 60 seconds with a sterile BBL CultureSwab. The collected specimens were cultured.

How Do Antiperspirants & Deodorants Affect Underarm Bacteria?

The investigators discovered that antiperspirants “…are capable of strongly reducing the biomass of the armpit microbial community…” In other words, the bacteria on the skin are killed off quite quickly by aluminum-containing antiperspirants, whether someone regularly used personal hygiene products or not. They also noted that “The effect of deodorant on bacterial abundance is more modest, if present at all.”

It is interesting to note that the research demonstrated that long-term users had substantially different bacterial growth in their underarms after stopping an aluminum antiperspirant compared to nonusers and deodorant users. The authors wrote:

“These compounds may alter the underarm habitat (in a manner that deodorants do not), and provide a selective advantage to bacteria not historically common in the human armpit habitat. Based on our study, this underarm habitat alteration lasts multiple days after stopping product use.”

The number of staphylococcaceae bacteria in the underarms of subjects who stopped aluminum antiperspirant use was nearly three times higher than in the people who never used such products. There was also a substantial increase in “other” bacterial strains compared to deodorant users and nonusers.

We find it somewhat shocking that no one has bothered to ask whether regular use of antiperspirants could have a negative impact on skin ecology. The researchers themselves seemed somewhat surprised that this question remains unanswered. Could antiperspirants allow for “less beneficial or even pathogenic bacterial species” to thrive? They simply do not know. These investigators note that their work:

“clearly demonstrates that antiperspirant use strikingly alters armpit communities, making them more species rich. Because antiperspirants only came into use within the last century, we presume that the species of bacteria they favor are not those historically common in the human armpit.”

Could Antiperspirants Make You Smellier?

Wouldn’t it be paradoxical if regular use of an aluminum antiperspirant made your underarms stinkier? That is what a different group of researchers reported (Archives of Dermatological Research, Oct. 2014). Scientists in Belgium concluded that:

“Antiperspirant usage led toward an increase of Actinobacteria, which is an unfavorable situation with respect to body odor development. These initial results show that axillary cosmetics modify the microbial community and can stimulate odor-producing bacteria.”

We interpret this to mean that regular users of antiperspirants may discover unpleasant body odor shortly after stopping use of such products. If true, this is clearly undesirable. It would be a powerful motivation to resume use of antiperspirants. Cosmetic manufacturers probably were unaware of this effect when they launched aluminum-containing antiperspirants. But such a “rebound” phenomenon would be a favorable outcome from a business perspective.

Stories from readers:

Mrs. Collins in Virginia shared this experience:

“I stopped using antiperspirant about 18 months ago. At first, my armpits had more odor. I didn’t have success with just deodorant right away. Instead, I neutralized the bacteria/odor every 2-3 days by dabbing tea tree oil on my underarms with a cotton ball and powdering with baking soda daily to keep my arm from feeling sticky and to prevent red bumps from chafing. I also alternated with vinegar on a cotton ball, if the tea tree oil was sometimes too strong (sometimes it irritated my skin after I’d shaved). After a few weeks, I was able to simply wash my underarm, apply deodorant (without antiperspirant) and go about my day odor-free.

“During the past year, I’ve attempted to use an antiperspirant a few times for long days at the beach or other all-day events where I’m very physically active. However, I didn’t get good results. My underarms would sweat even more than normal when I reintroduced the antiperspirant, and it was stinky sweat. Plain deodorant works much better. If doing sweaty activities, just reapply afterward. For best results, rewash your underarm with warm water or soap and water, and then reapply deodorant.

“From my experience, my sweat has a more natural scent that isn’t as odorous as when using the antiperspirant. I’m never going back, and I’m trying to get my husband off the antiperspirant because he wears it 24/7 and his armpits still get an odor from the buildup of bacteria.”

JoAnn in Delaware noted:

“I recently stopped using an antiperspirant as a result of reading articles about aluminum possibly being absorbed into the body. I tried your MoM Roll-on Deodorant for three days and every day my body odor increased.

“I’m wondering if stopping the antiperspirant cold-turkey caused the bacterial growth you mentioned. Of course, I went right back to my antiperspirant just as you also mentioned. How do I kill that bacteria to stop the body odor so I can make another attempt at using the MoM?”

Ken offered this solution:

“The rebound odor can be controlled by using rubbing alcohol splashed on a paper towel and using it to wipe down your pits.”

J. Ann in Pennsylvania reported:

“I had about a week of ‘transition’ when I stopped using antiperspirant in which I had yellow sweat with a horrible smell. After that, everything was fine. I always make sure to apply to just washed underarms. I haven’t had an odor problem in the years I’ve been using your MoM deodorant. Great product!”

The People’s Pharmacy Alternative:

If you would like to learn about how we developed aluminum-free MoM deodorant, here is a short video:


What users have to say about MoM:

Lars wants to know:

“Is there any danger or problem with using Milk of Magnesia itself, straight from the bottle? It works well as a deodorant. I had read years ago this was used by U. S. soldiers in World War II. Thank you.”

People’s Pharmacy Answers:

We used to use this liquid laxative ourselves after reading that it worked as a deodorant. There are only two problems:

  1. It is messy. You have to pour it into your palm and then slosh it on your underarms where it can drip. Some people use a cotton ball, but it is still a bit messy.
  2. The preservative that has been used in this oral laxative is sodium hypochlorite. That is known commonly as bleach. Even in small concentrations we were not thrilled with putting sodium hypochlorite on our underarms. That is why we developed MoM without this preservative.

Darshana in Menlo Park, California gave us a thumbs up review:

“I had given up deodorants, because I didn’t want the chemicals and couldn’t stand the fragrances. My chiropractor recommended against the crystal kind, so I just washed a lot, like in the middle of the day too.

“As life got more stressful, caring for my elderly parents, I had to use something, or I would stink, so I gave MoM a try. At first I didn’t like that it rolled on wet, and I had to learn not to put too much on. But as I got used to using a roll-on, I have come to LOVE this product! I never smell bad when I use it, you don’t need a lot, and really it dries pretty quickly.”

Chuck in Florida says it succinctly:

“I am 73 I have tried them all and this works.”

May in Naples Florida offers this:

“After trying out different products that were aluminum-free, I was not pleased with the results. I could smell perspiration on myself by evening. I am very pleased to say that I no longer have body odor since I got your MoM roller. It works and I love it!”

Find out for yourself. If you are not satisfied there is a no-questions-asked money-back guarantee. You will find all body care products at this link!

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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