What Is Myreth-3 Carboxylic Acid?
Myreth-3 Carboxylic Acid is a lab made ingredient created by attaching three small units of ethylene oxide to a fatty alcohol that is about 14 carbons long, then turning one end of that chain into a mild acid group. The fatty part comes from plant oils such as coconut or palm, while the rest is built through controlled chemical steps in a factory. This blend of fat and water loving parts makes it act like a surfactant, meaning it can break up oil and dirt so they rinse away easily.
The ingredient showed up in personal care formulas in the late 1980s when brands looked for gentler cleansers that produced less irritation than older soaps. By tweaking the chain length and the number of ethylene oxide units, chemists found a balance that cleaned well yet felt soft on skin and hair. Production starts with myristyl alcohol, which is reacted with three moles of ethylene oxide to make Myreth-3. That material is then lightly oxidized so one end turns into a carboxylic acid, boosting its water solubility.
You will spot Myreth-3 Carboxylic Acid in liquid face washes, foam cleansers, micellar waters, baby shampoos, body washes, exfoliating scrubs and makeup removers. It can also show up in gentle peel off masks or shaving preparations where a mild, non drying cleansing action is needed.
Myreth-3 Carboxylic Acid’s Cosmetic Benefits/Uses
This ingredient serves a single main role in formulas, offering the following benefit:
Cleansing: Myreth-3 Carboxylic Acid lowers the surface tension of water so oil, sweat, sunscreen and makeup lift off the skin or hair and rinse away. Because its structure is partly fatty and partly water friendly, it forms micelles that trap grime without stripping natural moisture, leaving a clean yet comfortable feel.
Who Can Use Myreth-3 Carboxylic Acid
Because it is a gentle surfactant that cleans without harsh stripping, Myreth-3 Carboxylic Acid suits most skin types including oily, combination, normal and sensitive skin. Very dry or eczema-prone complexions might feel a bit tight if the overall formula lacks extra moisturizers, so pairing it with hydrating ingredients is wise.
The fatty portion is typically sourced from coconut or palm oil and the rest is made synthetically, with no animal-derived raw materials or by-products. For that reason products using it are generally appropriate for vegans and vegetarians, though palm sourcing policies can vary by brand.
Current safety data shows no issues for pregnant or breastfeeding women when the ingredient is used in rinse-off or leave-on cosmetics at standard levels. This is not medical advice and anyone who is expecting or nursing should confirm any new skincare choice with a qualified health professional.
Myreth-3 Carboxylic Acid does not make skin more sensitive to the sun so there is no extra need for photo-protection beyond the usual daily sunscreen recommendation.
Potential Side Effects/Adverse Reactions
Responses to topical Myreth-3 Carboxylic Acid differ from person to person. The effects listed below are possible yet uncommon when products are formulated correctly.
- Mild eye irritation
- Temporary skin tightness or dryness, especially on already dehydrated skin
- Stinging on open cuts or freshly shaved areas
- Rare allergic contact dermatitis marked by redness itching or small bumps
If any uncomfortable reaction develops stop use promptly and consult a healthcare provider or dermatologist.
Comedogenic Rating
Rating: 1/5
Myreth-3 Carboxylic Acid is water soluble and designed to lift oil off the skin then rinse away cleanly. It does not linger in pores or leave a heavy film, which keeps the clogging risk low. Lab data and user reports rarely link it to blackheads or breakouts so it earns a score of 1 rather than a perfect 0 since any surfactant can cause issues if a formula is badly balanced.
With this low rating it is generally considered suitable for people prone to acne or frequent breakouts.
Formulas that pair it with very rich emollients could raise the overall comedogenicity so always look at the full ingredient list if congestion is a concern.
Summary
Myreth-3 Carboxylic Acid is a mild cleansing agent that mixes a fatty chain with three ethylene oxide units ending in a small acid group. This structure lets it latch onto dirt and oil while staying friendly with water so grime lifts off and washes away without stripping natural moisture.
It shows up mainly in face washes baby shampoos and micellar waters but it is not as famous as ingredients like sodium lauryl sulfate or coco glucoside. Brands that focus on gentle formulas appreciate its balance of cleansing power and softness even if it stays under the radar for most shoppers.
Current research and decades of safe use place it among the low risk cosmetic ingredients when used at normal levels in rinse off or leave on products. Still skin is personal so doing a quick patch test with any new product containing Myreth-3 Carboxylic Acid is a smart habit.