Sweating Is Important – but Rarely Welcome. Dermatologist Dr. Marion Runnebaum from Jena explains what helps against odor and dampness, how to properly use deodorants and antiperspirants, and what the ongoing debate around aluminum as an ingredient is really about.

How does a deodorant actually work – and how is it different from an antiperspirant?

Odor is caused when bacteria on our skin break down sweat. Deodorants target exactly this: they combat the bacteria. Antiperspirants, on the other hand, reduce the production of sweat itself. So if you‘re mainly bothered by wet underarms, an antiperspirant is the better choice. Only it can actually prevent sweating – at least in the area where it‘s applied.

Which ingredients are most effective against odor?

The classic „anti-smell“ heroes are antibacterial agents such as the now rarely used triclosan and modern alternatives like ethylhexylglycerin. Alcohol also helps kill germs. Many deodorants contain added fragrances to mask body odor. But: a good deodorant shouldn’t just cover up – it should prevent odor from forming in the first place.

And what about aluminum? This ingredient is frequently criticised – is that justified?

Aluminum is the active ingredient in antiperspirants. It blocks the sweat glands, so less moisture is produced. It’s a hot topic, but here’s the good news: according to current scientific research, there’s no solid evidence that aluminum in deodorants is harmful to health. The European Commission on Consumer Safety confirms: with normal use, there is no cause for concern.

How can you tell if you‘ve absorbed aluminum – and is it possible to remove it from the body?

Our bodies are smart. Excess aluminum is typically excreted through the kidneys. Only a tiny fraction is absorbed through the skin. If you‘re still worried, lab tests can measure aluminum levels in blood or urine – but this is generally unnecessary. “Detoxing” is usually redundant, as the body regulates it naturally.

Are there other ways to reduce sweating – and can that be harmful to health in general?

Sweating is vital – it‘s our body’s natural cooling system! Suppressing it locally, like under the arms, is generally harmless. Botox, for instance, temporarily inhibits sweat gland activity and can be a great option. Suctioning out the sweat glands is a permanent solution. Both should only be done for medical reasons and by professionals.

Does the body start sweating more in other areas then?

Yes, that can happen – it’s called compensatory sweating. If we „shut off the tap“ in one place, the body may find other ways to cool down. This is usually minimal, but with more aggressive interventions like surgery, it can be noticeable – for example, on the back or legs. That’s why the rule of thumb is: the more natural, the better. And always seek good medical advice for any treatment.

When do deodorants and antiperspirants work best?

The ideal time to apply antiperspirants is in the evening before bed. That’s when sweat glands are less active, allowing the ingredients to be absorbed overnight. Showering in the morning? No problem – the effect usually remains. Deodorants, on the other hand, should be applied in the morning. They work immediately, but typically don’t last as long.