What Is Potassium Laureth-5 Carboxylate?
Potassium laureth-5 carboxylate is the potassium salt form of laureth-5 carboxylic acid, a surfactant molecule created by reacting lauryl alcohol with ethylene oxide to add five ethoxy groups, then carboxylating and neutralising the result with potassium hydroxide. This process yields a water-soluble ingredient prized for its gentle foaming and cleansing properties. Surfactants like this one first gained popularity in the mid-20th century as cosmetic chemists searched for milder alternatives to traditional soaps. Over time manufacturers refined the synthesis steps to reduce impurities, improve skin compatibility and enhance biodegradability, leading to the version commonly used today. You will typically spot potassium laureth-5 carboxylate in facial cleansers, micellar waters, liquid hand soaps, body washes, bubble baths and shaving foams where a soft creamy lather is desired without stripping the skin.
Potassium Laureth-5 Carboxylate’s Cosmetic Benefits/Uses
This ingredient plays a focused yet valuable role in personal care formulas.
Cleansing: As a mild anionic surfactant it lowers the surface tension of water so oils dirt and makeup can be lifted from skin and rinsed away easily. Its ethoxylated structure helps create a dense but gentle foam that feels pleasant during use while its potassium salt form reduces the risk of dryness compared with harsher sulfate surfactants.
Who Can Use Potassium Laureth-5 Carboxylate
This surfactant is generally well tolerated by all skin types, including dry, oily, combination and sensitive skin. Its mild nature and low potential for residue make it a popular choice for people who find traditional sulfates too drying or irritating.
The ingredient is synthesized from plant-derived fatty alcohols and does not involve animal by-products so it is suitable for vegans and vegetarians.
Pregnant and breastfeeding individuals can use products containing potassium laureth-5 carboxylate as it is not known to penetrate deeply or accumulate, but this is not medical advice. Out of an abundance of caution anyone expecting or nursing should run new skincare products by a qualified health professional.
It does not cause photosensitivity, meaning it will not make skin more prone to sunburn or pigmentation when exposed to sunlight.
The ingredient is also free of common allergens such as gluten, soy and nut derivatives, making it a flexible choice for users with those specific concerns.
Potential Side Effects/Adverse Reactions
Individual responses to topical potassium laureth-5 carboxylate vary. The following list outlines potential side effects that have been reported but they remain uncommon when the ingredient is used at appropriate levels in a well-formulated product.
- Mild skin dryness if used in very high concentrations or in leave-on formats
- Transient stinging on compromised or freshly exfoliated skin
- Eye irritation if the cleanser accidentally gets into the eyes
- Rare contact dermatitis in individuals with a specific surfactant sensitivity
If irritation or any adverse reaction occurs discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
Potassium laureth-5 carboxylate is highly water soluble and does not leave an oily film on the skin, so it has an extremely low likelihood of blocking pores. Its large hydrophilic head groups help it rinse away completely, further reducing any chance of congestion. For these reasons it earns a rating of 1, indicating minimal comedogenic potential.
This makes the ingredient suitable for those prone to acne or breakouts, especially when used in rinse-off formats like cleansers and body washes.
Because the molecule is part of anionic surfactant families that do not tend to lodge within follicular openings, its comedogenic profile stays low even when combined with richer co-surfactants or oils in a formula.
Summary
Potassium laureth-5 carboxylate is primarily a gentle cleanser. By lowering water’s surface tension it lifts away excess sebum, makeup and dirt, while its ethoxylated chain creates a creamy foam that feels soft on the skin. The potassium salt form tempers harshness so users get effective cleansing without the tight after-wash feel common with stronger sulfates.
The ingredient has gained steady popularity in sulfate-free facial cleansers, micellar waters and baby washes, yet it remains less well known to shoppers than big names like sodium laureth sulfate. Formulators value it for its mildness and versatility which is why you often see it paired with amphoteric surfactants to further boost gentleness.
Safety data show a low risk of irritation or sensitisation and it seldom contributes to clogged pores. As with any new skincare product though, it is wise to perform a quick patch test to make sure your individual skin tolerates the full formula.