We all sweat. Why? To cool down our body. Sweat accompanies us since we are born. Thus it is a natural body reaction. Unfortunately, the bacteria that live on our skin produce a smell that is characteristic of sweat. We all smell differently, while each of us tends to fight with a natural body smell. The easiest way is to use an antiperspirant that may block sweat production, soak it or just mask it. Which way is the best one? An answer is hidden in INCI – the ingredients that are on the label. Some of them are safe for us, while some should never be used. How to find the bad ones? Within this paper, we will describe it in detail.
But what exactly is sweat? This is the secretion of the sweat glands. Its composition is variable, but the main ingredient is water but also minerals containing, for example, potassium or sodium, urea, and lactic acid. Our sweat is slightly acidic (pH ranges between 4.5 and 6.0) . In fact, it cools the overheated body and protects our skin by moisturizing it when it is too dry. Did you know that our body is covered with two types of glands? The first ones are eccrine sweat glands that are distributed almost all over the body. There are even 4 million of them, and they are responsible for the production of watery and salty sweat. The second type is apocrine sweat glands located mostly in our face, head, chest, and under the arms. The sweat produced by them differs from the first ones. This sweat is more viscous and contains proteins, sugars, lipids, and even ammonia with a characteristic unpleasant smell. Moreover, such sweat contains pheromones that stand behind sexual attraction. So, sweat also has more functions than just cooling down the body. 
Smell, smell go away.
Our skin is covered with bacteria, and they are responsible for the characteristic smell. Why? The sweat is just their food, while the smell of such bacteria comes from their metabolism products. Did you know that the smell of sweat depends on the diet? When we eat onion or garlic, the sweat smells more intensively than usual. Moreover, our smell may change if we are ill, e.g. having diabetes. 
To mask the smell, we use antiperspirants. Some are liquid, some are solid, others are sold as a deodorant in spray, while all contain chemical compounds that have some function. There are two main types of antiperspirants: the first one soaks the sweat or reduces its amount, while the second one just masks its smell. Which one is better? It depends on many factors, including physical activity, health condition, age, and much more, so it is difficult to say. However, some antiperspirants contain chemicals that are not safe for us. If you see these names on your antiperspirants, better run. Let’s take a look closer at them.
Triclosan, its name does not sound scary, does it? It is a compound that very often can be found in cosmetics. In a recent decade, triclosan was widely added to many cosmetics due to its antibacterial and antifungal properties. Still, unfortunately, there are many studies about its negative impact on living organisms. It is widely added to toothpaste, anti-acne cosmetics, soaps, and antiperspirants . Unfortunately, it is harmful to our bodies. Despite its prohibition in recent years, it still can be found in cosmetics, and the problem is still omnipresent . This compound may cause several diseases from hypothermia, cardiac disturbances to even cancer. In the environment, triclosan undergoes natural degradation and is quickly neutralized. However, studies show that a particular part of the compound degrades under the sunlight, giving rise to certain breakdown products that are toxic for us. Moreover, the widespread use of this compound with antimicrobial activity has contributed to an increase in the number of strains of bacteria resistant to them .
Thanks to parabens – strong preservatives, the cosmetic product has an extended expiry date and does not spoil immediately after opening. Research has unequivocally identified links between frequent contact with parabens and cancer development . Parabens have antifungal and antibacterial activity, so they are widely added into soaps, antiperspirants, and shampoos as an anti-dandruff agent. Parabens are contact allergens. They are one of the most contact sensitizers, although they are considered to be very weak allergens. Allergic reactions are usually mild, cause itching, erythema, but atopic dermatitis may also develop .
Aluminum is a heavy metal that is not needed in our bodies. Unfortunately, it is widely added to antiperspirants in various forms. There are many concerns about its negative influence on our body. It may cross biological membranes like our skin, and when it enters the body, it may cause several diseases. Recent studies show that this metal and its compounds cause allergies and skin inflammation . Lengthy exposition on cosmetics with aluminum enlargement of lymph nodes and when accumulated in the body, it may be even more dangerous. Did you know an evident relation between aluminum and brain diseases like multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease? It happens because aluminum compounds tend to cause inflammation of neurons. Moreover, it may cause bone problems and anemia . Sounds scary, doesn’t it?
To or not to smell? That is the question. Antiperspirant helps us to keep fresh, protect against odor, and sweat too. We dare to say that we all wish wet underarms are a thing of the past, so we use these fantastic cosmetics. They just make us more comfortable at meetings and fresh during many stressful situations. Whenever you choose an antiperspirant, remember the harmful ingredients mentioned above to minimize the risk of many disorders or diseases, and you will be sure they are safe.
This article is a joint work of Magdalena Abramowicz (Faculty of Chemistry, University of Warsaw), Emilia Cywińska (Faculty of Chemistry, University of Warsaw), Agnieszka Pregowska (Institute of Fundamental Technology Research, Polish Academy of Sciences), and Magdalena Osial (University of Warsaw, Faculty of Chemistry). Image Credit: Magdalena Osial. This article is a part of the Science Embassy project.
 Bochenek A., Reicher M.: Anatomia człowieka: podręcznik dla studentów i lekarzy. Wyd. 3(2). Tom 5. Warszawa: PZWL, (1989)
 Baker L.B.: Physiology of sweat gland function: The roles of sweating and sweat composition in human health. Temperature (2019) 6(3) 211–259
 Jones R. D., Jampani H. B, Newman J. L., Lee A. S.: Triclosan: a review of effectiveness and safety in Heath care settings. Am. J. Infect. Control. (2000) 28:184-196
 Adolfsson-Erici M., Petterson M., Parkkonen J., Sturve J.: Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden. Chemosphere, 2002, 46: 1485-1489
 Izydorczak M., Stefańska J.: Środek przeciwdrobnoustrojowy Triclosan-działanie, zastosowanie i zagrożenia, Biuletyn WUM, (2007)
 Darbre P.D., Harvey P.W.: Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks, Journal of Applied Toxicology (2008) 28: 561-78
 Soni M.G, Taylor S.L., Greenberg N.A., Burdock G.A., Evaluation of the health aspects of methyl paraben: a review of the published literature, Food and Chemical Toxicology (2002) 40(10): 1335-1373
 Flarend, R., Bin, T., Elmore, D., & Hem, S. L.: A preliminary study of the dermal absorption of aluminium from antiperspirants using aluminium-26. Food and chemical toxicology, (2001) 39(2): 163-168.
 D. Krewski, R.A. Yokel, E. Nieboer, D. Borchelt, J. Cohen, J., Harry, J., V.Rondeau, Human health risk assessment for aluminium, aluminium oxide, and aluminium hydroxide. Journal of Toxicology and Environmental Health, Part B, 2007;10(S1): 1-269.
You can offer your link to a page which is relevant to the topic of this post.