What Is Disodium Undecylenamido Peg-2 Sulfosuccinate?
Disodium Undecylenamido Peg-2 Sulfosuccinate is a synthetic ingredient that starts with undecylenic acid, a fatty acid usually sourced from castor oil. Chemists link this acid to polyethylene glycol (PEG) units then add a sulfosuccinate group, ending with a water-friendly sodium salt. The result is a molecule with one part that loves oil and another that loves water, perfect for lifting dirt and oil from skin and hair.
The first sulfosuccinate surfactants appeared in the 1940s as milder options than traditional soaps. Over time formulators discovered that attaching undecylenic acid and short PEG chains gave even softer cleansing and better foam, so the ingredient found its way into modern personal care lines.
Production involves reacting undecylenic acid with PEG-2, adding maleic anhydride to form a succinate ring, sulfonating the ring then neutralizing the mix with sodium hydroxide. The multi-step process is carried out in closed reactors to keep the final powder or liquid free from unwanted residues.
You will most often see Disodium Undecylenamido Peg-2 Sulfosuccinate in sulfate-free shampoos, facial cleansers, micellar waters, baby washes, body washes, shaving foams and bubble baths. Its mild nature also makes it popular in makeup removers and cleansing masks where gentle yet effective action is required.
Disodium Undecylenamido Peg-2 Sulfosuccinate’s Cosmetic Benefits/Uses
This ingredient brings several practical perks to a formula
- Cleansing: Breaks up oil, sweat and makeup so they can be rinsed away without stripping the skin or hair of moisture
- Foam Boosting: Creates a rich stable lather that helps spread the product evenly and gives a satisfying sensory feel
- Hydrotrope: Keeps other surfactants and oily actives dissolved in water-based formulas which improves clarity and prevents separation
Who Can Use Disodium Undecylenamido Peg-2 Sulfosuccinate
This surfactant is generally well tolerated by all skin types including dry, normal, combination, oily and sensitive. Because it cleans without high abrasion or high pH it rarely causes tightness or redness, even on reactive skin. People with known sensitivities to any type of PEG or sulfosuccinate surfactant should proceed cautiously, otherwise it is widely considered suitable for everyday use.
The raw material is synthesized from castor oil and other non animal sources so it is appropriate for vegans and vegetarians. As always check the full ingredient list of the finished product, as other components may not be animal free.
No specific warnings exist for use during pregnancy or while breastfeeding. It is not absorbed through intact skin in meaningful amounts. Still this is not medical advice and anyone who is pregnant or nursing should review all personal care products with a physician or midwife for peace of mind.
The ingredient does not cause photosensitivity and has no known interaction with sun exposure. It can be safely paired with daily SPF products.
Formulators often choose it for baby shampoos and family cleansers thanks to its low irritation profile, making it an option for children as well as adults.
Potential Side Effects/Adverse Reactions
Individual responses to topical Disodium Undecylenamido Peg-2 Sulfosuccinate can differ. The effects listed below are possible yet uncommon when the ingredient is used at normal cosmetic levels
- Mild skin irritation such as redness or itching, usually linked to very sensitive skin or overuse
- Eye stinging if the product comes in direct contact with the eye surface
- Temporary dryness or tight feeling when left on the skin for prolonged periods
- Rare allergic contact dermatitis presenting as rash or swelling
If any irritation or discomfort develops stop using the product and consult a healthcare professional if symptoms persist or worsen
Comedogenic Rating
Rating: 0 / 5
Disodium Undecylenamido Peg-2 Sulfosuccinate is highly water soluble and does not form an occlusive film on skin, so it is very unlikely to clog pores or trap sebum. It is usually found in rinse-off products where contact time is short, further reducing any pore-blocking risk.
Suitable for people who are prone to acne or breakouts.
Because it is typically blended with other gentle surfactants in low-to-moderate amounts the overall formula remains light and easy to rinse, helping keep pores clear.
Summary
Disodium Undecylenamido Peg-2 Sulfosuccinate acts mainly as a mild cleanser, foam booster and hydrotrope. Its oil-loving tail grabs dirt, oil and makeup while its water-loving head lets everything rinse away cleanly. By stabilising lather and helping dissolve other ingredients it improves both texture and performance in sulfate-free shampoos, face washes, baby cleansers and similar products.
Although not as famous as older surfactants like sodium laureth sulfate it has carved out a steady place in modern gentle formulas, especially those marketed as sensitive-skin friendly.
Current safety data shows a low irritation profile, minimal absorption and virtually no comedogenicity. Still, everyone’s skin is unique so it is smart to patch test any new product that contains this ingredient before adding it to a regular routine.