Beards and microbes: What the evidence shows

Daily Maverick

26-06-2025

A microbiologist explores the science behind beard hygiene.
Beards have long attracted suspicion, sometimes seen as stylish, sometimes as unsanitary. But how dirty are they, really?
Human skin is home to billions of microorganisms – mainly bacteria, but also fungi and viruses – and facial hair provides a unique environment for them to thrive. Research shows that beards, in particular, support a dense and diverse microbial population, which has fuelled a persistent belief that they are inherently unhygienic. The Washington Post recently reported that some toilets contain fewer germs than the average beard.
But are beards truly a hygiene risk? A closer look at the evidence reveals a nuanced picture.
The microbial population on skin varies by location and is influenced by factors such as temperature, pH, humidity and nutrient availability. Beards create a warm, often moist environment where food debris and oils can accumulate – ideal conditions for microbial growth.
These microbes thrive not just because of the warm, moist conditions beards provide, but also because of constant exposure to new contaminants and microbes, especially from hands that frequently touch surfaces and the face.
Concerns among scientists about beard hygiene date back over 50 years. Early studies showed that facial hair could retain bacteria and bacterial toxins even after washing. This led to the enduring idea that beards act as bacterial reservoirs and could pose an infection risk to others.
For healthcare workers, this has made beards a point of controversy, especially in hospitals where pathogen transmission is a concern. However, hospital-based research has shown mixed results. One study found that bearded healthcare workers had higher bacterial loads on their faces than clean-shaven colleagues.
Another investigation, looking at whether it would be hygienic to evaluate dogs and humans in the same MRI scanner, found that most men's beards contained significantly more microbes than dog fur, including a greater presence of harmful bacteria. The researchers concluded: 'Dogs are no risk to humans if they use the same MRI.'
However, other studies have challenged the idea that beards increase infection risk. For example, one investigation found no significant difference in bacterial colonisation between bearded and clean-shaven healthcare workers.
The same study also reported that bearded doctors were less likely to carry Staphylococcus aureus, a major cause of hospital infections, and that there was no increase in infection rates among patients treated by bearded surgeons wearing surgical masks.
Beards can sometimes spread skin infections, such as impetigo — a contagious rash often caused by S aureus, which is commonly found in facial hair. In rare cases, parasites like pubic lice – which usually live in the groin area – can also show up in beards, eyebrows or eyelashes, particularly in cases of poor hygiene or close contact with an infected person.
The case for good beard hygiene
Neglected beards can foster irritation, inflammation and infection. The skin beneath a beard – rich in blood vessels, nerve endings and immune cells – is highly sensitive to microbial and environmental stressors. When sebum, dead skin, food debris and pollutants accumulate, they can irritate the skin and provide fuel for fungal and bacterial growth.
Experts strongly recommend washing your beard and face every day. Doing so removes dirt, oils, allergens and dead skin, helping prevent microbial buildup.
Dermatologists also advise moisturising to prevent dryness, using a beard comb to clear debris, and trimming to control loose hairs and reduce shedding. These steps help maintain not only hygiene but also beard health and appearance.
So, are beards dirty? Like most things, it depends on how well you care for them. With daily hygiene and proper grooming, beards pose little risk and may even be healthier than we once thought. DM