potassium alum as deodorant/antiperspirant

Greetings, thanks for your help.

Im planning to make a liquid or gel deodorant ussing the raw materials available in my country, i dont have any complain with zirconium or aluminium chlohydrates but they are not availables, so i was wondering ussing potassium alum or magnessium hydroxides wich it seams that are being used as sustitutes in aluminium-free formulas. So i just want to know if some one has an experience using alum ór magnesium hydroxides and can gives me a tip or just let me know if experimenting with they worths the shame.


  • There is a very interesting investigation of the evaluation of potassium alum as deodorant, 2% of potassium alum would be a starting point, but i dont have access to laboratories or the time/money to test the product in people to certificate the effectiveness of alum as deodorant, and it would be very expensive to make an investment in raw materials unknowing the results. so i would apreciate any experience or knowledge that anyone can have.

  • I don't have any knowledge of magnesium hydroxide as antiperspirant, but it could be used to buffer the alum.  I do have experience using alum (both potassium & ammonium) in antiperspirants on myself.  Alum has long use in such a role, but is irritating on its own.  It can be made milder, but also less effective, by buffering it with alkali.  Different people have different susceptibility to irritation by aluminum salts, and for some people the pH you'd have to get up to to make it no longer irritating would make it completely ineffective as antiperspirant.  Some people can tolerate alum solution unbuffered.  It has to be somewhat acidic to work at all.

    Increasing pH also decreases its water solubility.  Water-insoluble complexes of aluminum can be delivered as suspended powders or in some non-aqueous vehicle.  I buffered alum with sodium bicarbonate in water, and shook it immediately before spraying on the armpit from a nose spray bottle; it did tend to clog, though.

  • Chemist77Chemist77 Member, PCF student
    I used it in a mild emulsion and it worked out just fine, let me know if you need the formulation as well. Don't mind sharing it and if it works out fine for you with few tweaks and modifications depending on the RM availability in your country. 
  • Thanks @robertg and @chemist77 for your help, im waiting until next week for potassium alum to arrive, i will let you know if it works for me, i will start ussing 1%-2% alum playing with alkali in a aqueus emulsion suitable for roll-on bottles. Any formulation that you could provide would be vere usefull
  • MarkBroussardMarkBroussard Member, Professional Chemist

    Potassium Alum dissolved in water has a native pH of 2.5 or so.  It is effective as a deodorant because of the low pH.  If you add alkali to the formulation, you are defeating the purpose of using Potassium Alum to begin with.

    Use Potassium Alum at 8% to 10%.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thanks @markbroussard, i will test it at your recommended level, i was thinking in adjusting the ph to 3.5 - 4, to avoid irritaton or skin incompatibility.
  • chemicalmattchemicalmatt Member, Professional Chemist
    What I'd like to know is how all the marketers of these potassium alum salt stick deodorants are feeling about themselves by claiming "aluminum-free" on their labels?
  • I wish i could have aluminium/zirconium chlorohydrates available in my country, im just trying to offer a deodorant with the only raw materials available. I feel bad about myself having to offer products that have been discotinued around the world or were formulated like 20 years ago.
  • Gretings, just tried some formulations for about 1 month in 15 test subjects including myself and i got this results:

    Ph 3,5-3,8 doesnt show irritation on the skin ussing it daily for about 1 month

    It works well as deodorant, but not as antiperspirant

    5% was the minimun concentration of alum and 8% the maximun, there were no substantial diference in the results

    the formulation is a traslucent gel that includes xanthan gum, potash alum, polysorbate 80, edta, fragance, glycol stearate, citric acid/sodium hidroxide, and water.

    I will apreciate any help with the main problem:

    Some of the test subjetcs where complaining about the "sensation of protection" of the deodorant was lasting from 3 hours to 5 hours, i want to know it someone has a tip to raise that sensation, i made a little poll , and the users want to feel a layer of the deodorant on the skin for at least 5-8 hours. Part of the problem could be the abdsortion of the liquid on the shirt and evaporation of the gel.

  • That's interesting, because of the lengths some formulators go to to make such a product feel like nothing!

    I take it that glycol stearate is the monostearate, i.e. half ester. Maybe if you switched to the distearate it would feel waxier, and would continue to feel waxy as the arm rubbed against the shoulder all day. That or just increasing the amount of monostearate.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Potassium Alum functions as a deodorant. I does not function as an antiperspirant as it does not block the sweat glands, but does kill bacteria.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thanks @RobertG , im going to increase the amount of gms and see what happends, i was thinking in adding another wax like cetyl alcohol, or adding silicones to it.

    Thanks @MarkBroussard , it is working very well as deodorant.
  • DilfreDilfre Member
    Hi Luis, what a good info you've posted, it helped me a lot thanks
  • Thanks from me too, Luis, useful to know that pH 3.5 doesn't cause problems, at least in the short term, and my intended product is "occasional use".
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • @Dilfre @Belassi , your welcome, good to know that my post was usefull for you.

    Im still ussing and making large batches of rollon deodorant ussing alum and still working very well and only have one or two issues with irritation or intoleration.
  • Unknown Member
    Hi everyone,
    I did  a cream formula based on the article you posted, it was very greasy so i had to increase water amount and increase the aluminum salt, it worked for more than 12 hours.
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