What Is Arachideth-37?
Arachideth-37 is a nonionic surfactant created by attaching an average of 37 ethylene oxide units to arachidyl alcohol, a fatty alcohol that usually comes from plant oils such as peanut or rapeseed. The result is a waxy, water-soluble compound that bridges the gap between oil and water in a formula. Polyethylene glycol ethers like this entered mainstream cosmetic manufacturing in the 1950s when formulators sought gentler alternatives to soap-based cleansers, and the ingredient family has grown ever since.
Production starts with isolating arachidyl alcohol from vegetable oil, then running it through an ethoxylation process in which ethylene oxide gas reacts with the alcohol under controlled heat and pressure. Adjusting reaction time lets chemists dial in the average chain length, so “37” signals the typical number of ethylene oxide units added.
Thanks to its dual water-loving and oil-loving nature, Arachideth-37 shows up in facial cleansers, cream and milk makeup removers, moisturizers, sheet masks, leave-on skin treatments, hair conditioners and even some anti-aging emulsions where a stable, silky texture is prized.
Arachideth-37’s Cosmetic Benefits/Uses
In everyday products Arachideth-37 plays two main roles that improve both performance and user experience
- Cleansing: Its surfactant action lifts away dirt, excess oil and makeup then helps them rinse off without leaving a tight or squeaky feel, making formulas milder than traditional soap systems
- Emulsifying: By keeping oil and water phases uniformly mixed it prevents separation, giving creams and lotions a smooth, stable texture and ensuring active ingredients are evenly distributed each time you apply
Who Can Use Arachideth-37
Arachideth-37 is generally considered suitable for most skin types including oily, combination and normal skin because it cleanses without a harsh stripping effect. Dry or very sensitive skin can also tolerate it in low to moderate amounts, yet those prone to eczema or allergic reactions to polyethylene glycols may prefer to steer clear or opt for patch-tested formulas.
The ingredient is almost always sourced from plant oils and synthesized through an entirely chemical process, so products using Arachideth-37 are normally vegan and vegetarian friendly. If animal origin is a concern, look for brands that specify plant-derived fatty alcohols.
No data suggest that the ingredient poses a specific risk to women who are pregnant or breastfeeding when used topically and in the low percentages found in cosmetics. That said, this is not medical advice and expecting or nursing mothers should show the full ingredient list of any product to their healthcare provider before adding it to a routine.
Arachideth-37 does not increase photosensitivity, so it will not make skin more prone to sunburn. It is also odorless and free of essential oils or fragrance allergens, another plus for sensitive noses.
Potential Side Effects/Adverse Reactions
Reactions to Arachideth-37 vary from person to person. The following is a list of potential side effects, though most people will not experience them when the ingredient is used correctly in a well-formulated product.
- Transient stinging or redness, especially on compromised or freshly exfoliated skin
- Mild contact dermatitis in individuals allergic to polyethylene glycol derivatives
- Eye irritation if a cleanser containing Arachideth-37 is not rinsed out thoroughly
- Dryness or tightness when used in very high concentrations or paired with aggressive surfactants
- Trace 1,4-dioxane contamination if the manufacturing process is not properly controlled, which could increase irritation risk
If any irritation or adverse effect occurs stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1/5 Arachideth-37 is highly water soluble and typically used at low levels as a helper surfactant or emulsifier, so it is unlikely to remain on the skin long enough to block pores. Its large PEG chain further reduces the chance of it solidifying inside follicles. Overall buildup is minimal which keeps the rating close to non-comedogenic.
For most people prone to acne it should not be a trigger, especially in rinse-off cleansers or lightweight lotions.
The final pore-clogging potential depends on the full formula: rich butters, waxes or silicones paired with Arachideth-37 could raise the overall risk even if this single ingredient scores low.
Summary
Arachideth-37 acts as a gentle cleanser and reliable emulsifier. Its amphiphilic structure lets it surround oil and dirt so they lift away with water, while also locking water and oil phases together for smooth stable creams.
It is not the most famous name on an ingredient list but formulators appreciate it for producing milder, silkier textures than harsher surfactants. You will see it sprinkled across cleansers, makeup removers and a handful of moisturizers where low irritation and a velvety feel are priorities.
Current data show it to be low risk for toxicity, irritation and comedogenicity when used at normal cosmetic levels. As with any new product it is wise to patch test first to rule out personal sensitivities before applying it widely.