Amp-Isostearoyl Hydrolyzed Corn Protein: 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 23, 2025
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All information on this page is verified using The Personal Care Products Council's (PCPC) INCI database. Our ingredient analyses are based exclusively on PCPC's technical data to ensure accuracy and reliability.

What Is Amp-Isostearoyl Hydrolyzed Corn Protein?

Amp-Isostearoyl Hydrolyzed Corn Protein is a specialty ingredient made from corn. Makers first break down corn protein into smaller pieces through a process called hydrolysis. These small protein fragments are then linked with a fatty substance known as isostearic acid chloride. Finally, the mixture is neutralized with aminomethyl propanol so it can blend smoothly with water and oil in cosmetic formulas.

The idea of pairing plant proteins with fatty chains started gaining ground in the late 1990s when brands looked for nature-inspired ways to improve hair feel and skin softness. Corn was an obvious choice because it is plentiful, renewable and already used in many personal care materials. Today the ingredient is produced in large batches: manufacturers hydrolyze corn protein, couple it with isostearic acid chloride in a controlled reactor then adjust the pH with aminomethyl propanol to create a stable salt.

Because it carries both water-loving and oil-loving parts, Amp-Isostearoyl Hydrolyzed Corn Protein fits well into products that need to coat and protect surfaces. You will most often see it in shampoos, rinse-off and leave-in conditioners, hair masks, styling creams, skin lotions, facial moisturizers and body butters.

Amp-Isostearoyl Hydrolyzed Corn Protein’s Cosmetic Benefits/Uses

This ingredient serves two key roles that improve how hair and skin products perform.

  • Hair conditioning: The corn-derived peptides cling lightly to damaged hair strands while the isostearoyl part adds a silky layer of softness. The result is easier combing, less breakage and a smoother look without heavy buildup.
  • Skin conditioning: On skin the protein fragments form a thin, breathable film that helps hold moisture and leave the surface feeling soft. The fatty chain boosts spreadability so lotions and creams glide on more evenly and feel cushiony instead of greasy.

Who Can Use Amp-Isostearoyl Hydrolyzed Corn Protein

Because it is lightweight and non occlusive, this ingredient is generally considered suitable for all skin types including oily, combination, normal and dry. Sensitive skin users usually tolerate it well since it has no known harsh actives, though anyone highly reactive to corn-derived materials should proceed with caution.

Vegans and vegetarians can comfortably use it because it is sourced from plant-based corn protein and synthetic fat derivatives, with no animal testing typically required for its approval.

Current safety data indicates no inherent risks for pregnant or breastfeeding users. Still, this is not medical advice and anyone expecting or nursing should review new personal care products with a healthcare professional to be certain they meet individual needs.

Amp-Isostearoyl Hydrolyzed Corn Protein does not absorb UV light and is not known to increase photosensitivity, so it can be used day or night without raising sun-related concerns.

Potential Side Effects/Adverse Reactions

Responses to topical Amp-Isostearoyl Hydrolyzed Corn Protein vary from person to person. The points below describe potential but uncommon issues. In properly formulated products most users experience none of these effects.

Allergic contact dermatitis – rare in the general population yet possible for individuals allergic to corn proteins or isostearic derivatives

Mild skin irritation – slight redness or itching can occur if the formula contains a high percentage of the ingredient or if skin is already compromised

Eye stinging – when used in rinse-off hair products that accidentally run into the eyes some people may feel temporary discomfort

If any negative reaction appears discontinue use immediately and seek advice from a qualified healthcare provider

Comedogenic Rating

Rating: 1/5 – Amp-Isostearoyl Hydrolyzed Corn Protein contains small, partially water-soluble protein fragments paired with a branched fatty chain that does not readily pack into pores. Its film sits lightly on skin and rinses away without leaving thick residue, so the chance of clogging is very low.

That means most acne-prone users can comfortably use products containing this ingredient.

As with any conditioning agent, the final formula matters more than the single raw material. Heavy oils, waxes or silicones in the same product could raise the overall comedogenicity even if this ingredient stays low.

Summary

Amp-Isostearoyl Hydrolyzed Corn Protein is a corn-based hybrid that conditions hair and skin by forming a thin, breathable protein film while its fatty tail smooths and softens. This dual nature helps detangle strands, cut frizz, boost moisture retention and improve cream spreadability.

It is not a headline superstar yet it shows up quietly in a fair number of modern hair masks, shampoos and lightweight lotions because it delivers slip and softness without heaviness.

Current safety data points to a low risk of irritation or pore blockage, making it safe for most users when used as directed. As with any new cosmetic we recommend a quick patch test to be on the safe side before adding a product containing this ingredient to your routine.

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