Ingredient review

Methylhydantoin-Imide

INCI: 1-METHYLHYDANTOIN-2-IMIDE

A synthetic humectant that helps skin retain moisture, but research on its long-term effects is still limited.

beautyskincarehumectant

In plain English

This ingredient is a lab-made compound that attracts water to the skin's surface, helping it stay hydrated. It works similarly to glycerin but is less common in everyday products. Because it's relatively new in cosmetics, there isn't a lot of independent research on how it performs compared to more established humectants.

Quick decision guide

Useful, but context matters

Methylhydantoin-Imide is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Methylhydantoin-Imide.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

emerging

The ingredient may be promising, but claims should be treated more cautiously.

What it is

A synthetic derivative of hydantoin, a small molecule that can bind water and improve skin hydration. It is produced in a laboratory and not found naturally in plants or animals.

How it works

It acts as a humectant by drawing moisture from the environment or deeper layers of the skin into the outer layer, temporarily increasing water content. It also forms a thin film that helps reduce water loss, leaving skin feeling softer.

Pros

Effective humectant

Helps attract and retain moisture in the outer skin layer, which can improve hydration and reduce dryness.

Low irritation potential

Generally well-tolerated by most skin types, with a low risk of causing redness or stinging.

Cons and cautions

Limited research

There are few peer-reviewed studies on this specific ingredient in cosmetic formulations, so its long-term safety and efficacy are not as well-established as common humectants like glycerin.

Synthetic origin

It is not naturally derived, which may be a drawback for consumers seeking natural or organic skincare options.

Best for

  • People with normal to dry skin looking for extra hydration
  • Those who tolerate synthetic humectants well

Use caution if

  • Individuals with known sensitivity to hydantoin derivatives
  • Anyone seeking only plant-based or natural ingredients

Usage tips

Use in a moisturizer or serum after cleansing to lock in hydration.
Pair with occlusive ingredients like shea butter or dimethicone to prevent moisture loss.

Safety summary

Generally considered safe for topical use at low concentrations. However, due to limited independent safety data, it is best suited for occasional or short-term use until more research is available.

Research notes

There are very few published studies on 1-methylhydantoin-2-imide in cosmetics. Most available information comes from manufacturer data and safety assessments for similar hydantoin derivatives.

Common label clues

Typical concentration
Typically used at 0.5–2% in leave-on products
Regulatory status
Approved for use in cosmetics in the EU and US, but not specifically reviewed by the Cosmetic Ingredient Review (CIR) panel as of 2025.
Common uses
Moisturizers, Serums, Facial creams
Environmental note
As a synthetic compound, its biodegradability and environmental impact are not well-documented. It is not known to be bioaccumulative.

Good to know

  • This ingredient is not related to formaldehyde-releasing preservatives, despite the 'hydantoin' name.
  • It is often used in combination with other humectants for a synergistic hydrating effect.

Common questions

What is Methylhydantoin-Imide in beauty products?

This ingredient is a lab-made compound that attracts water to the skin's surface, helping it stay hydrated. It works similarly to glycerin but is less common in everyday products. Because it's relatively new in cosmetics, there isn't a lot of independent research on how it performs compared to more established humectants.

What does Methylhydantoin-Imide do in a beauty product?

It acts as a humectant by drawing moisture from the environment or deeper layers of the skin into the outer layer, temporarily increasing water content. It also forms a thin film that helps reduce water loss, leaving skin feeling softer.

Is Methylhydantoin-Imide safe for most people?

Generally considered safe for topical use at low concentrations. However, due to limited independent safety data, it is best suited for occasional or short-term use until more research is available.

Who should be careful with Methylhydantoin-Imide?

Individuals with known sensitivity to hydantoin derivatives Anyone seeking only plant-based or natural ingredients

Research sources

European Chemicals Agency (ECHA) – 1-Methylhydantoin-2-imideOpenCosIng – European Commission databaseOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.