Science
Mechanism of Action
This compound acts primarily as a reducing agent, selectively cleaving the disulfide bonds within the keratin structure of hair, thereby weakening the hair shaft for effortless removal or reshaping. This reductive process can also induce transient alterations to the stratum corneum proteins and intercellular lipids of the skin barrier. Crucially, the strontium ion component provides a distinct benefit, demonstrating a capacity to reduce various forms of sensory irritation, including stinging, burning, and itching, through its interaction with PAR2 receptors.
Research
Clinical Evidence
High confidence5%
Transparency
Dusting Analysis
The Formula
Formulation
Stability
The stability of thioglycolate solutions, particularly their susceptibility to oxidation, is significantly influenced by preparation methods. Oxidation rates generally increase with rising pH and storage temperature, especially in heated solutions. Unheated solutions may exhibit higher initial alkalinity, with pH potentially decreasing over time. Dilution can also accelerate oxidation during storage. For enhanced stability, thioglycolic acid in gel formulations demonstrates better preservation when stored in glass bottles compared to polyolefin containers. Depilatory efficacy specifically demands a highly alkaline pH range of 12.0-12.5.
Conflicts
- High concentrations of strontium salts can destabilize emulsion systems and lead to the precipitation of various ingredients, including proteins, commonly found in topical formulations. This can result in reduced shelf-life and increased product tackiness.
- The divalent strontium cation and the thioglycolate moiety's inherent oxidation potential, particularly at elevated pH, present challenges in maintaining emulsion stability and overall product integrity.
Safety
Safety Profile
Strontium Thioglycolate, as part of the thioglycolic acid and its salts family, is considered safe for cosmetic use under specific restrictions established by regulatory bodies like the SCCS and CIR. While in vitro and animal studies indicate potential for ocular and skin irritation, as well as sensitization, clinically significant adverse reactions in formulated depilatory products are uncommon, suggesting that products are engineered to be practically non-irritating under recommended use conditions. The ingredient is listed in the FDA Global Substance Registration System (UNII-8H9L5LC23Q).
Your Skin
Skin Compatibility
Our Assessment
Verdict
Strontium Thioglycolate is a valuable ingredient for targeted hair removal and permanent waving applications, offering the unique benefit of irritation mitigation alongside its potent reducing action, provided it is precisely formulated within established concentration and pH parameters.
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