Antiperspirant, deodorant harm underarm bacteria: Study

antiperspirant-deodorant-harms-underarm-bacteria-studyAntiperspirant and deodorant may keep you dry and smelling good, but new findings suggest they harm good bacteria of the underarm. Although the researchers are unaware whether the disruption of bacteria has any negative consequences, it is still important to note there is possibility that antiperspirant may pose a threat.

Our skin is covered in microbes, many of which help protect it by blocking out harmful bacteria or signaling to the immune system of what is going on. Lead researcher Julie Horvath said, “We know that these skin microbes interact with the immune system. So it’s important to consider what our daily habits do to the skin’s microbiome.”


Horvath noted that the study was not intended to discourage people from using deodorant, but rather raise awareness that anything we put on the skin – lotion, makeup, etc. – can change the skin’s microbes.
Horvath and her team first originally swabbed their own armpits and tested the cultures to determine what microbes were present. During that process, Horvath was using clinical-strength antiperspirant, and found that she had no microbes. She explained, “I thought, ‘Where are my microbes? And then I remembered the clinical-strength antiperspirant’.”

The team then recruited 17 volunteers. Some used antiperspirant, others used deodorant, and some used neither product. Over the course of eight days, they followed their normal hygiene routine on day one, on days two to six they didn’t use any underarm product, and for the last two days they all used antiperspirant.

Armpit swabs showed the lowest bacteria count for antiperspirant, and the highest for deodorant users. The differences come from the fact that antiperspirants stop the sweat which bacteria thrive on, while deodorant simply prevents odor.

Among those who didn’t use underarm products, the most common bacteria were corynebacteria (62 percent) and staphylococcaceae (21 percent). In underarm product users, there was far more staph bacteria than corynebacteria.

Corynebacteria is mainly responsible for odor, but may also protect the body from harmful bacteria, and staph typically is known to be a harmful but can be beneficial as well.


As stated, the effects of different underarm products are still unclear. Further research is required to determine the effects of such products.



Author Bio

Emily Lunardo studied medical sociology at York University with a strong focus on the social determinants of health and mental illness. She is a registered Zumba instructor, as well as a Canfit Pro trainer, who teaches fitness classes on a weekly basis. Emily practices healthy habits in her own life as well as helps others with their own personal health goals. Emily joined Bel Marra Health as a health writer in 2013.