C12-13 Alketh-5 Carboxylic Acid: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: June 24, 2025
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All information on this page is verified using publicly available nomenclature standards and reference materials from The Personal Care Products Council (PCPC) and the European Commission's CosIng database. Our analyses are based on technical data from these sources to ensure accuracy and reliability.

What Is C12-13 Alketh-5 Carboxylic Acid?

C12-13 Alketh-5 Carboxylic Acid is a synthetic fatty acid derived from medium-chain alcohols that come from natural oils such as coconut or palm kernel. Chemically it features a C12-C13 carbon chain linked to about five units of ethylene oxide, ending with a carboxylic acid group. This structure lets the molecule attract both oil and water, a trait that makes it valuable in skin-care formulas.

The ingredient was developed in the late twentieth century when chemists looked for milder alternatives to older, harsher detergents used in soaps and shampoos. By adjusting the carbon chain length and the number of ethylene oxide units they created a cleanser that works well at low concentrations while being gentle on skin.

Manufacturing starts with fatty alcohols sourced from plant oils. These alcohols undergo ethoxylation, where ethylene oxide reacts with the alcohol to add the five repeating units. The product is then oxidized to convert the end of the chain into a carboxylic acid, yielding a viscous liquid that blends easily with water-based systems.

You will most often see C12-13 Alketh-5 Carboxylic Acid in facial cleansers, body washes, micellar waters, exfoliating masks and occasionally in makeup removers. Formulators like it because it produces a soft, low-foam lather, leaves minimal residue and pairs well with conditioners and moisturizers.

C12-13 Alketh-5 Carboxylic Acid’s Cosmetic Benefits/Uses

This ingredient is valued mainly for one key role:

Cleansing: Its dual-natured structure loosens dirt, excess oil and makeup so they can be rinsed away with water. Because it is milder than traditional sulfates it helps leave skin feeling clean yet comfortable reducing the tight or squeaky sensation some cleansers can cause.

Who Can Use C12-13 Alketh-5 Carboxylic Acid

The gentle cleansing action makes this ingredient suitable for most skin types including oily, combination, normal and even mildly dry skin since it removes debris without stripping away too much natural oil. People with very dry or severely compromised skin may still prefer richer cream cleansers that leave more residue because their barrier needs extra support.

C12-13 Alketh-5 Carboxylic Acid is plant derived and produced without animal by-products so it aligns with vegan and vegetarian values.

No studies suggest any special risk for women who are pregnant or breastfeeding when the ingredient is used at normal cosmetic levels. This is not medical advice and anyone expecting or nursing should show any new skincare product to a healthcare professional just to be safe.

The molecule does not absorb UV light so it is not known to cause photosensitivity. It also plays well with the vast majority of other common skincare ingredients which is why formulators often blend it into multi-step routines.

Potential Side Effects/Adverse Reactions

Reactions to topical C12-13 Alketh-5 Carboxylic Acid differ from person to person. The effects listed below are possible yet uncommon when the ingredient is used at the levels seen in finished products.

  • Transient skin dryness
  • Redness or mild irritation in very sensitive users
  • Stinging if applied to open cuts or broken skin
  • Allergic contact dermatitis in rare cases
  • Eye irritation if the product accidentally gets into the eyes

If any of these issues occur discontinue use and seek advice from a medical professional.

Comedogenic Rating

Rating: 1/5 (very low)

This ingredient is highly water soluble and is almost always used in rinse-off formats so it does not remain on the skin long enough to clog pores. Its job is to remove excess oil rather than coat the surface, which keeps the likelihood of congestion minimal.

Generally suitable for acne prone or breakout prone skin.

The only potential concern is if residue is not rinsed off thoroughly, in which case any surfactant can mix with sebum and dead cells and create minor buildup.

Summary

C12-13 Alketh-5 Carboxylic Acid acts as a gentle cleanser, using its oil-loving chain and water-loving head to surround grime then carry it away during rinsing. This balance delivers a soft low-foam wash that leaves skin clean yet comfortable.

It is a behind-the-scenes staple in facial cleansers body washes and micellar waters rather than a spotlight ingredient, but formulators keep returning to it because it pairs mildness with reliable performance.

Testing and long-term marketplace use show it is generally safe with only rare irritation reports. Even so it is wise to patch test any new product containing this or any other active to be certain your skin agrees.

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