What Is Sodium Arachidate?
Sodium arachidate is the sodium salt of arachidic acid, a long-chain fatty acid also called eicosanoic acid that naturally occurs in peanut oil, corn oil and other plant fats. When the fatty acid reacts with sodium hydroxide it forms this white to off-white powder that dissolves in water and takes on mild surfactant properties. Soap makers have used similar sodium fatty acid salts for centuries, so the leap into modern skin care happened as formulators saw how reliably these salts stabilize emulsions and adjust pH. Today most cosmetic-grade sodium arachidate is produced by saponifying purified arachidic acid sourced from vegetable oils, followed by filtration and drying steps that remove excess alkali and impurities. You will most often spot it in facial cleansers, bar soaps, creamy body washes, makeup removers, lotions, sunscreens and some specialty masks where a consistent texture and gentle cleansing action are needed.
Sodium Arachidate’s Cosmetic Benefits/Uses
In formulas sodium arachidate serves several helpful roles that improve both product performance and feel on the skin.
- Buffering: Helps keep the product’s pH within a skin-friendly range which protects the formula and reduces the risk of irritation.
- Emulsion stabilising: Prevents water and oil phases from separating so creams and lotions stay smooth and uniform during shelf life.
- Cleansing: Acts as a mild surfactant that lifts away dirt, excess oil and makeup without stripping the skin’s natural barrier.
- Emulsifying: Binds oil and water together during production allowing formulators to create rich yet lightweight textures.
- Viscosity controlling: Adds body or thickness to a product so it feels substantial in the hand and spreads evenly over the skin.
Who Can Use Sodium Arachidate
Sodium arachidate works for most skin types including normal, oily and combination because it offers gentle cleansing and helps control texture without leaving a heavy residue. Sensitive or very dry skin can usually tolerate it as well, though formulas with a high percentage of surfactants could feel a bit drying if other soothing agents are not present.
The ingredient is sourced from vegetable oils, not animal by-products, so it is suitable for vegans and vegetarians.
Current safety data shows no specific risks for pregnant or breastfeeding women when the ingredient is used topically at cosmetic concentrations. This is not medical advice and anyone who is pregnant or nursing should review any skincare product with their doctor to be on the safe side.
Sodium arachidate is not known to cause photosensitivity so it will not make skin more prone to sunburn. Users should still follow standard sun protection practices when spending time outdoors.
Potential Side Effects/Adverse Reactions
Responses to topical sodium arachidate vary from person to person. The following is a list of potential side effects that could occur, though most users will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild skin dryness: Surfactant activity can strip some natural oils if used in high amounts or combined with other strong cleansers
- Transient stinging or redness: May appear on very sensitive or compromised skin especially if the product has a higher pH
- Allergic contact dermatitis: Rare but possible for individuals with an existing fatty acid or peanut oil sensitivity
- Eye irritation: Can cause temporary burning or watering if a cleanser containing the ingredient gets into the eyes
If irritation or any negative reaction occurs stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1/5. As the sodium salt of arachidic acid, sodium arachidate becomes water soluble and functions more like a mild surfactant than an occlusive oil so it rarely blocks pores. Most leave-on products include it at very low levels for pH control or emulsion stability which further reduces any clogging risk. In rinse-off cleansers it is quickly washed away. For these reasons it is generally suitable for acne-prone skin. Formulas that pair it with heavy oils or waxes could still feel greasy on very oily skin so the full ingredient list matters.
Summary
Sodium arachidate buffers pH, stabilises and builds emulsions, provides gentle cleansing and tweaks viscosity. It does this by carrying a negative charge that neutralises excess alkali, surrounding oil droplets so they stay dispersed, lowering surface tension to lift dirt then thickening the water phase slightly for a creamier feel. While not a headline ingredient it appears quietly in a variety of cleansers, lotions and sunscreens because it is dependable, vegan friendly and cost effective. Safety assessments find it non toxic and unlikely to irritate when used at cosmetic levels. As with any new product a small patch test is wise to rule out personal sensitivity.