# Crystal Deodorant - How does it work? **URL:** \ **Category:** Factual Questions\ **Created:** [January 16, 2004, 11:34pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857 "2004-01-16T23:34:26Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Stainz](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@Stainz](https://boards.straightdope.com/u/Stainz)\ **Post date:** [January 16, 2004, 11:34pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/1 "2004-01-16T23:34:26Z")
For the past couple of years, I’ve mainly used the “crystal” deodorants instead of the brands such as Arrid, Secret, etc. But I’m wondering WHY the crystal kind works … and what kind of salt does it contain, is it aluminum salt? Thanks, S. ---
**Author:** ![Alereon](https://avatars.discourse-cdn.com/v4/letter/a/ecd19e/32.png) [@Alereon](https://boards.straightdope.com/u/Alereon)\ **Post date:** [January 17, 2004, 12:47am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/2 "2004-01-17T00:47:10Z")
It contains normal, run of the mill sodium chloride. The salt residue remains on your skin, making the environment inhospitable for the lovely little bacteria that produce body odor. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [January 17, 2004, 4:44am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/3 "2004-01-17T04:44:58Z")
They work great! Oh wait, there was more to the question. Alereon, you got a cite for the NaCl formulation? That doesn’t sound right to me, since my crystal gets dunked in water every day, and still lasts for years. ---
**Author:** ![Peregrine](https://avatars.discourse-cdn.com/v4/letter/p/a6a055/32.png) [@Peregrine](https://boards.straightdope.com/u/Peregrine)\ **Post date:** [January 17, 2004, 6:15am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/4 "2004-01-17T06:15:13Z")
Not NaCl, but K2SO4AL2(SO4)3 24H2O, also known as potassium alum, or hydrated sulfate of potassium and aluminum. (Although the manufacturers of crystal deodorant work very hard to make you think there is no aluminum.) ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [January 17, 2004, 6:40am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/5 "2004-01-17T06:40:45Z")
Crystal deodorant is a SCAM. Lets see some cites here guys, remember where you are. Off looking for de-bunking cites. ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [January 17, 2004, 6:54am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/6 "2004-01-17T06:54:53Z")
Here’s the stuff. [http://mineral.galleries.com/minerals/sulfates/hanksite/hanksite.htm](http://mineral.galleries.com/minerals/sulfates/hanksite/hanksite.htm) Or what was most commonly reported to be “natural deoderant”. My guess is if your BO aint bad enough to notice, this stuff works wonders. ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [January 17, 2004, 6:59am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/7 "2004-01-17T06:59:23Z")
Here is the MSDS for the second most common ingredient. Suspiciously the ingredient in all the “sprayable” products. [http://ptcl.chem.ox.ac.uk/MSDS/PO/potassium\_chloride.html](http://ptcl.chem.ox.ac.uk/MSDS/PO/potassium_chloride.html) ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [January 17, 2004, 7:02am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/8 "2004-01-17T07:02:58Z")
MSDS for Potassium Alum. A common name for a component in the crystals ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [January 17, 2004, 7:04am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/9 "2004-01-17T07:04:53Z")
Aaak Sorry hamsters [http://physchem.ox.ac.uk/MSDS/AL/aluminium\_potassium\_sulfate\_12-hydrate.html](http://physchem.ox.ac.uk/MSDS/AL/aluminium_potassium_sulfate_12-hydrate.html) ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [January 17, 2004, 5:50pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/10 "2004-01-17T17:50:56Z")
> [@](#): > > _EvilGhandi wrote:_ > Crystal deodorant is a SCAM. What do you mean by a scam? You mean that paying $5 for a chunk of this chemical is way too expensive? Or that it doesn’t actually prevent body odor? If you mean the latter, I would encourage you to conduct your own test of it. I have, by using it every day, and it quite clearly works very well. ---
**Author:** ![MeanJoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/meanjoe/32/5693_2.png) [@MeanJoe](https://boards.straightdope.com/u/MeanJoe)\ **Post date:** [January 17, 2004, 9:19pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/11 "2004-01-17T21:19:52Z")
It is interesting as I use a potassium alum block as part of my shaving routine. I run one under cold water and rub it over my wet face after shaving, before applying my after-shave lotion. The cold helps to close the poors and the alum soothes the skin. Of course, as a shaving supply I pay a fortune for a tiny block. I saw these “deodorants” for the first time a week ago for considerably less money. MeanJoe ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [January 18, 2004, 12:40am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/12 "2004-01-18T00:40:58Z")
Anyone who says it’s a scam has never tried it. It worked very very well for me, for about a year . . . and then I apparently developed an allergy to it or something: 24-hour pit itch, which stopped when I stopped using the crystal. ---
**Author:** ![The\_Asbestos\_Mango](https://avatars.discourse-cdn.com/v4/letter/t/edb3f5/32.png) [@The\_Asbestos\_Mango](https://boards.straightdope.com/u/The_Asbestos_Mango)\ **Post date:** [January 18, 2004, 1:53am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/13 "2004-01-18T01:53:46Z")
> [@CurtC](#): > > What do you mean by a scam? You mean that paying $5 for a chunk of this chemical is way too expensive? Or that it doesn’t actually prevent body odor? > > If you mean the latter, I would encourage you to conduct your own test of it. I have, by using it every day, and it quite clearly works very well. I have to second this. I use a crystal deodorant, and it works extremely well. I’m one of those people who has a very strong underarm odor- even if I’ve showered that morning (I usually bathe/shower at night), if I’ve done anything that could result in any real perspiration, such as, say, a 20-30 minute walk, if I forget to use the deodorant, I can get quite funky. With the crystal deodorant, the odor is nonexistant. I think the people who consider it a scam probably do so because the crystal doesn’t function as an anti-pespirant. You’ll still sweat using it, you just won’t smell. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [January 18, 2004, 5:12am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/14 "2004-01-18T05:12:52Z")
Maybe by “scam” he meant either that it’s not really a “natural” product, or that it’s not significantly different from other deodorant products. For the former, I don’t care whether it’s labelled “natural.” I’d wear DDT if I could get it to repel mosquitoes. For the latter, I had not found any other comparable product. Anti-perspirants cause me to itch severely, and regular deodorants are just a perfumey smell in a suspension - they do nothing to prevent odor. If there are products comparable to the crystal, I don’t know about them. ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [January 18, 2004, 8:56pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/15 "2004-01-18T20:56:20Z")
Why do deodorants stop working? I find that I have to switch brands every few years, because the brand I’ve been using seems to stop working. I’ve used the “crystal” type before, and after 8-9 months it suddenly became ineffective. Do the skin bacteria all of a sudden become immune to the stuff? ---
**Author:** ![FilmGeek](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@FilmGeek](https://boards.straightdope.com/u/FilmGeek)\ **Post date:** [January 18, 2004, 9:27pm UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/16 "2004-01-18T21:27:33Z")
I had two friends who used crystals and usually stunk to high heaven. So, is there aluminum in crystal deodorant or not? ---
**Author:** ![clayton\_e](https://avatars.discourse-cdn.com/v4/letter/c/c57346/32.png) [@clayton\_e](https://boards.straightdope.com/u/clayton_e)\ **Post date:** [January 19, 2004, 11:16am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/17 "2004-01-19T11:16:05Z")
Why is aluminum such a thing to be avoided in deoderant? ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [December 6, 2013, 4:34am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/18 "2013-12-06T04:34:39Z")
I was going to start a thread asking this, but apparently it was asked 9 years ago without an answer. I can’t use anti-perspirants and deodorants do almost nothing but cover up the smell for a couple hours. Even if I wash again and reapply deodorant midday the odor comes back in a few hours. But a crystal deodorant (granted I just started using them today) has kept me odor free for 16 hours. So it must be doing something. Everything I read mentions how it ‘builds a barrier against bacteria’. So I don’t know if the crystals actually form a film that the bacteria can’t penetrate, or if they just create an environment very inhospitable to bacteria or what. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [December 6, 2013, 5:05am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/19 "2013-12-06T05:05:37Z")
Yes, potassium aluminum sulfate, the active ingredient in crystal deodorants, has aluminum in it. Does your product have a label that says what’s in it, **Stainz**? ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [December 6, 2013, 5:19am UTC](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857/20 "2013-12-06T05:19:39Z")
> [@Wesley\_Clark](#): > > I can’t use anti-perspirants and deodorants do almost nothing but cover up the smell for a couple hours. > > Everything I read mentions how it ‘builds a barrier against bacteria’. So I don’t know if the crystals actually form a film that the bacteria can’t penetrate, or if they just create an environment very inhospitable to bacteria or what. No barrier. Changes the environment. The environment the bacteria grows in is mostly in the HAIR, and that is why its so smelly - the sulfur in the hair is released by the bacteria.. (the bacteria release enzymes which breaks down the hair.) So really you want anti-bacterial stuff on the hair !. Deoderant sometimes means just a purfume. The aluminium salts are anti-perspirant and also anti-bacterial . . [Next page](https://boards.straightdope.com/t/crystal-deodorant-how-does-it-work/224857.md?page=2)