Magnesium Pca

Magnesium PCA is a magnesium salt of pyrrolidone carboxylic acid used primarily as a humectant/skin-conditioning agent, typically at low percentages (about 0.1–3%) in leave-on products. Available patch-test and clinical use experience suggest a low incidence of irritation and sensitization, with reactions being uncommon and usually limited to highly compromised or very reactive skin. Given its generally good tolerability but acknowledging that salt forms can occasionally sting on barrier-impaired eczema skin, it fits best as very gentle rather than inert. Safety Notes: In commercial leave-on moisturizers, serums, and scalp tonics, Magnesium PCA is commonly used at low supportive levels (~0.05–0.5%) as part of an NMF/mineral-PCA complex for hydration and barrier support. Higher-strength consumer products marketed for oil-control, soothing, or “mineral PCA” claims (often alongside Zinc PCA and/or Sodium PCA) can reach ~1–3%, with the upper end around ~5% seen in some specialty OTC concentrates; above this, tackiness/solubility and overall electrolyte load typically limit practical use. Rinse-off cleansers and shampoos usually sit toward the low end (about 0.05–0.3%) due to cost and limited contact time.