What Is Peg-5 Cocomonium Methosulfate?
Peg-5 Cocomonium Methosulfate is a quaternary ammonium compound made from coconut-derived fatty acids that have been reacted with about five units of ethylene oxide, then neutralized with methyl sulfate. The result is a water-soluble, positively charged ingredient that clings to hair or skin surfaces. Quats like this began appearing in personal care formulas in the 1950s when formulators looked for gentler options to tame static without weighing hair down. Today it is produced in large reactors where refined coconut oil is split into fatty amines, those amines are ethoxylated, then the final quaternization step locks in the cationic charge.
You will most often spot Peg-5 Cocomonium Methosulfate in rinse-off and leave-in conditioners, hair masks, detangling sprays, anti-frizz serums and some conditioning shampoos. Its mild nature also makes it a secondary conditioning agent in a few skin lotions and cream cleansers where a soft after-feel is desired.
Peg-5 Cocomonium Methosulfate’s Cosmetic Benefits/Uses
Formulators reach for this ingredient because it provides a simple yet important benefit:
As an antistatic agent, Peg-5 Cocomonium Methosulfate reduces the buildup of electric charge on hair fibers. This keeps strands from flying away, makes combing easier and leaves hair with a smoother look and feel.
Who Can Use Peg-5 Cocomonium Methosulfate
This conditioning quat is gentle enough for all skin and hair types, including dry, oily, and combination. Because it is water soluble and typically used at low levels, it rarely leaves a heavy residue that would bother acne-prone or sensitive skin. There are no known reasons for people with a specific skin type to avoid it unless they have a personal allergy to coconut-derived ingredients.
Peg-5 Cocomonium Methosulfate is made from plant-based coconut oil and synthetic processing aids, so it is suitable for both vegans and vegetarians. No animal derivatives or by-products are involved in its manufacture.
Current safety data do not flag this ingredient as a concern for women who are pregnant or breastfeeding. Still, this is not medical advice and it is wise for anyone who is expecting or nursing to show the full product label to a healthcare professional before adding it to a routine.
The ingredient does not increase photosensitivity. Standard sun protection habits are all that is needed when using products that contain it.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient can vary from person to person. The points below outline potential side effects associated with Peg-5 Cocomonium Methosulfate, though most people will never experience them when the ingredient is used properly in a finished formula.
- Mild skin irritation such as redness or itching, most often in those with very sensitive skin
- Allergic contact dermatitis in individuals specifically allergic to coconut-derived compounds
- Eye irritation if a rinse-off product containing the ingredient accidentally gets into the eyes
- Product buildup leading to limp or weighed-down hair when used in excessive amounts or not rinsed thoroughly
If you notice any of these reactions, stop using the product and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 1 (very low likelihood of clogging pores)
Peg-5 Cocomonium Methosulfate is highly water soluble and is used in small amounts that rinse cleanly from skin and hair, so it does not form the kind of oily film that can block pores. Its positive charge helps it bind to damaged hair proteins rather than sitting on skin, further reducing any chance of buildup. For these reasons it earns a low score of 1.
People who are prone to acne or breakouts can usually use products containing this ingredient without concern.
Because it is almost always paired with cleansing agents in rinse-off formulations, any residue left behind is minimal, which helps keep the comedogenic risk low.
Summary
Peg-5 Cocomonium Methosulfate is a coconut-derived quaternary ammonium compound that works primarily as an antistatic and light conditioning agent. Its positive charge lets it attach to negatively charged hair fibers, smoothing cuticles and cutting down static so hair feels softer and is easier to comb.
While it is not the most famous conditioning quat on the market, formulators appreciate its mildness and rinseability, so it shows up in a steady stream of conditioners, detanglers and a few skin care products that aim for a silky after-feel.
Current safety data show it is well tolerated by most users with only rare reports of irritation or allergy. Patch testing any new product is still the safest approach, especially for those with sensitive or reactive skin.