What Is Peg-5 Isodecyloxypropylamine?
Peg-5 Isodecyloxypropylamine is a synthetic ingredient made by attaching five units of ethylene oxide (the PEG-5 part) to isodecyloxypropylamine, an amine derived from isodecyl alcohol. The result is a clear to pale yellow liquid that dissolves well in water and oils, giving formulators flexibility when building products.
The compound was introduced in the late 1990s as cosmetic chemists searched for gentler alternatives to older antistatic agents that could leave heavy buildup. By tweaking the length of the PEG chain they found a sweet spot—the five-unit version delivers effective static control without weighing hair down or leaving a greasy feel on skin.
Manufacturing starts with isodecyl alcohol, which can be sourced from petrochemical feedstocks or vegetable oils. The alcohol is first reacted with propylene oxide to add a short propyl spacer, then treated with ethylene oxide in a controlled, step-wise process. Each addition of ethylene oxide attaches another ethoxy unit, and when the average reaches five the reaction is stopped. Finally the mixture is purified to remove unreacted materials and stabilized for shelf life.
You will most often find Peg-5 Isodecyloxypropylamine in rinse-off and leave-on hair products such as shampoos, conditioners, anti-frizz sprays, detangling mists and styling creams. It also turns up in some skin lotions and light emulsions where formulators want to cut back on static cling in fabrics or hair that may brush against treated skin.
Peg-5 Isodecyloxypropylamine’s Cosmetic Benefits/Uses
This ingredient serves a single purpose in personal care formulas, and it does it well.
Antistatic: Peg-5 Isodecyloxypropylamine carries a slight positive charge that neutralizes the negative charges building up on hair fibers, the main cause of static flyaways. By smoothing out electrical charges it helps hair lie flat, look sleeker and feel softer. Because the molecule is partly water-soluble it rinses cleanly, preventing heavy residue and allowing hair to retain natural bounce.
Who Can Use Peg-5 Isodecyloxypropylamine
This ingredient is gentle enough for all skin and hair types, including oily, dry and sensitive. Its low molecular weight and balanced charge let it rinse away without clogging pores or leaving a heavy film, so even acne-prone users usually tolerate it well.
Peg-5 Isodecyloxypropylamine is made from petrochemical or plant-based raw materials and contains no animal-derived substances, making it appropriate for vegans and vegetarians. As always, final product ethics depend on the brand’s overall policies and local animal testing laws.
Topical use during pregnancy or while breastfeeding is generally viewed as low risk because the molecule stays mostly on the surface and has minimal systemic absorption. This is not medical advice and anyone who is pregnant or nursing should confirm product choices with a doctor.
The ingredient does not cause photosensitivity so it will not make skin more prone to sunburn. It is also unlikely to interfere with common actives like vitamin C or retinoids, letting you layer products without worry.
Potential Side Effects/Adverse Reactions
Responses to topical Peg-5 Isodecyloxypropylamine vary from person to person. The effects listed below are possible yet uncommon when the ingredient is used at the typical levels found in finished cosmetics.
- Mild skin redness or stinging
- Temporary eye irritation if the product accidentally gets into the eyes
- Allergic contact dermatitis in individuals already sensitized to amine or PEG compounds
- Flat or slightly greasy hair feel if a leave-in product is overapplied
If you notice any discomfort or a persistent reaction stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1 out of 5. Peg-5 Isodecyloxypropylamine contains a short hydrophobic tail but is highly ethoxylated, which makes it readily soluble in water and easy to rinse off. Because it does not leave a thick, oily film on skin it poses very little risk of blocking pores. This low residue profile keeps the rating close to non-comedogenic levels, though a trace of lipid character prevents it from being a perfect zero.
Given the rating of 1, the ingredient is generally considered suitable for people who are prone to acne or breakouts.
No data suggest it exacerbates fungal acne and it does not interact with most acne treatments, making it a low-concern choice in multi-step routines.
Summary
Peg-5 Isodecyloxypropylamine is used almost exclusively as an antistatic agent. Its mildly positive charge binds to the negatively charged surface of hair, neutralising static and smoothing flyaways while its partial water solubility prevents heavy buildup.
The ingredient is a niche pick rather than a blockbuster, showing up in some modern shampoos, conditioners and light leave-ins where brands want reliable static control without a greasy feel.
Safety studies and decades of cosmetic use point to a low irritation profile, and the comedogenic rating of 1 means minimal pore-clogging risk for most users. As with any new product, do a quick patch test before full use to confirm your skin or scalp agrees with it.