Topically applied naturally occurring aluminum crystals are minimally absorbed, typically less than 0.015%.¹ The form found in the stones (aluminum sulfate, or "alum salt") is considered less likely to cause skin problems than the forms of aluminum found in commercial deodorants/antiperspirants (aluminum chloride, aluminum zirconium tetrachlorohydrex etc.) and have lower absorption potential, two reasons why the stones have become popular.

 

¹ Pharmacol Toxicol. 2001 Apr;88(4):159-67. Aluminum toxicokinetics: an updated minireview. Yokel RA, McNamara P.

 

 

Disclaimer: These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.