Zinc oxide use in natural deodorants
I have been searching for a long time a natural deodorant that really works and that I can make myself.
By really works I mean that you can:
- do sport activities
- climb a mountain on a 25°C full sunny day
- spend a hot day in a hot town
… and in the evening you still smell good. Or at least as good as using a classical deodorant (which is not always the best choice either).
I thought I’ve tried all natural deodorants that exist:
- alcohol based
- witch hazel based
- with baking soda
- with alum
- with antibacterial essential oils
- … and combinations of these…
But… at the end of the day I and my clothes still smelled unpleasant. And after sporty activities or in a hot weather, even worse. I do not sweat a lot – actually, almost not at all…. however all these deodorants just at the end of the day failed.
Not to talk about my fiancé, who sweats much more than me – all these did not convince him at all. He tried patiently, though…
And then, I found ZINC OXIDE aka ZnO !!!!!
Zinc oxide is a perfect active ingredient for natural deodorant
Why? I have made some research – including scientific papers – and I do bring you what I found, including the citations…
- Zinc oxide reacts with short fatty acids that are responsible for the unpleasant odor – by converting them into odorless zinc salts (much like the sodium hydroxide reacting with fatty acids in oils to produce soap) [1,3]
- Zinc oxide is three times more effective than aluminium chlorhydrate, used in deodorants and antiperspirants 
- It is antibacterial, so partially inhibits bacterial growth, inhibiting thus the decomposition of sweat , which is the main reason of unpleasant odor [3,4]. Not sure (meaning I did not find a scientific base for this) if it inhibits exactly those living in our armpits, but it works …-
- it is a powder, absorbing thus to some extent the sweat and the absorbed part does not decompose so fast
- is not absorbed by skin (particles above 30nm, be aware of nano-particles smaller than 30 nm!)
Disadvantage? It does not stop the sweating. You will sweat less but it won’t function as an 100% antiperspirant. My fiancé said: I sweat less than not using any and at the end of the day I smell considerably less than using some of the classical antiperspirants…
I must say, he really does not smell at the end of the day (I can feel something only if I put my nose in his armpit… )
Zinc oxide deodorant in test
For a week we (me + my fiancé) have tested the pure zinc oxide powder as deodorant and we were very happy about its performance. However, it was during the week, and we work sitting in our offices, so no big deal. Moreover, we did not like the powder form, which is difficult to apply.
I prepared a sunblock cream with 30% Zinc oxide for testing purposes and we used it also as a deodorant.
The test that persuaded us was the climbing of La Berneuse (2045m), Switzerland, 12:00 – 19:30, full sun, 25°C in shadow – with the absolute elevation gain of 700m, in total 1000m.
Success: 100% – at the end of the day we both smelled only the white tea fragrance I added to the cream.
Comparison to other natural deodorants
The recipe that will follow is not the same as the one I used for sunblock recipe, as for deodorant I do not have to add all the expensive ingredients that are not necessary for deodorant.
kept the 30% of ZnO [EDIT 15 July 2016: looking back at my recipe, I used 15.5% ZnO]and used aloe vera juice for the water phase (it has soothing properties, which is nice for armpits, where a lot of friction goes on)
The new version of the deodorant is as efficient as the “sunblock” version (have been using it for months since daily).
- I prefer this recipe over my stick deodorant recipe. The active ingredient there are baking soda, which should similarly to zinc oxide neutralize the short fatty acids responsible for malodour, and the antibacterial essential oil. I do not say it does not work at all …. I say that it smells bizarre at the end of the day – maybe because of present butters and oils, that are decomposed in advantage to our sweat. More baking soda could help, but as it is never 100% dissolved (it dissolves in water, not in oils) , it creates friction and in consequence a skin redness already in small quantities… In comparison, Zinc oxide is very fine and can be added in a quantity up to 30% (maybe more, but not necessary).
- I was afraid that zinc oxide will stain white my clothes, but my worries turned out to be totally unjustified. First, I was afraid and put the deodorant before dressing up, waiting it to dry while I brushed my teeth. With time I became lazy and applied it when dressed… guess what – nothing changed. If you pay attention, the clothes are not stained outside and the very little that is stained on the inner side is very easily washable. In comparison to my stick deodorant, which actually stains my clothes to yellow, this is really negligible.
- This deodorant has a cream consistency. I prefer it this way. First, when water phase is present, you can easily disperse zinc oxide in it and the smaller quantity of oils is advantageous – any possible decomposition/oxidation is much lower and it does not grease the clothing.
- Of course, once water phase is present, we have to preserve it in order to stop the bacterias – we try to stop these!!! I opted for Optiphen – it does not contain parabens, has quite wide antibacterial spectra and is recognized as an ingredient in natural cosmetics (what is natural…that is the question…)
Södeberg TA, Sunze B, Holm S, Elmro T, Hallmans G, Sjöberg S. Antibacterial effect of zinc oxide in vitro. Scand. J. Plast. Reconstr. Hand. Surg. 24: 193-7, 1990.
 Kanda, F, Yagi, E, Fukuda, M, Nakajima, K, Ohta, T, Nakata, O. Elucidation of chemical compounds responsible for foot malodour, Brit. J. Dermatol., 122, 771-776 (1990).
 Wysocki, C.J., Zeng, X-N. and Preti, G. (1994) Specific anosmia and olfactory sensitivity to 3-methyl-2-hexenoic acid: A major component of human axillary odor. Chem. Senses, 1993, 18:652