Ingredient review

Magnesium Aluminum Hydroxide Carbonate

INCI: MAGNESIUM/ALUMINUM/HYDROXIDE/CARBONATE

A safe mineral stabilizer and absorbent used in many cosmetics, but not a star active ingredient.

beautyskincareabsorbent

In plain English

This is a mineral powder made from magnesium, aluminum, hydroxide, and carbonate. In cosmetics, it helps absorb excess oil, gives products a smooth texture, and can make formulas look more opaque or creamy. Think of it like a very fine, gentle clay that helps keep makeup and skincare products stable and pleasant to use.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Risk flags are low for most users, though the finished product can still irritate.

Source
synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

Magnesium Aluminum Hydroxide Carbonate 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 Magnesium Aluminum Hydroxide Carbonate.
  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

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic mineral compound that combines magnesium, aluminum, hydroxide, and carbonate ions into a fine, white powder.

How it works

It works by absorbing moisture and oil from the skin's surface, and by scattering light to create a matte or opaque appearance in the product. It also helps stabilize emulsions (mixtures of oil and water) so they don't separate.

Pros

Oil control

Effectively absorbs excess sebum and sweat, helping to reduce shine throughout the day.

Texture improvement

Gives creams, powders, and foundations a silky, smooth feel that glides on easily.

Cons and cautions

Not hydrating

This ingredient does not add moisture to the skin; it can even feel slightly drying if used in high amounts.

Limited skin benefit

It is a functional ingredient (stabilizer, absorbent) rather than an active that improves skin health.

Best for

  • People with oily or combination skin looking for oil control
  • Anyone who wants a smooth, matte finish in makeup or skincare

Use caution if

  • Those with very dry or dehydrated skin who prefer hydrating formulas

Usage tips

Look for it in powder foundations or mattifying primers for best oil-control results.
If you have dry skin, pair products containing this ingredient with a good moisturizer.

Safety summary

Considered safe for topical use in cosmetics at typical concentrations. The aluminum is chemically bound and not readily absorbed through intact skin. Some individuals with very sensitive skin may experience mild irritation, but this is rare.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that magnesium/aluminum/hydroxide/carbonate is safe for use in cosmetics. No significant toxicity or sensitization has been reported in human studies.

Common label clues

Typical concentration
Typically 0.5% to 5% in leave-on products
Regulatory status
Approved for use in cosmetics by the FDA and EU CosIng database as a safe color additive and cosmetic ingredient.
Common uses
Foundations, Powders, Creams, Lotions
Environmental note
Synthetic mineral compounds are generally considered low environmental impact, but mining of raw materials can have ecological effects.

Good to know

  • It is often used in combination with other powders like talc or silica to fine-tune texture.
  • The aluminum content is bound in a mineral complex and is not considered bioavailable in topical use.

Common questions

What is Magnesium Aluminum Hydroxide Carbonate in beauty products?

This is a mineral powder made from magnesium, aluminum, hydroxide, and carbonate. In cosmetics, it helps absorb excess oil, gives products a smooth texture, and can make formulas look more opaque or creamy. Think of it like a very fine, gentle clay that helps keep makeup and skincare products stable and pleasant to use.

What does Magnesium Aluminum Hydroxide Carbonate do in a beauty product?

It works by absorbing moisture and oil from the skin's surface, and by scattering light to create a matte or opaque appearance in the product. It also helps stabilize emulsions (mixtures of oil and water) so they don't separate.

Is Magnesium Aluminum Hydroxide Carbonate safe for most people?

Considered safe for topical use in cosmetics at typical concentrations. The aluminum is chemically bound and not readily absorbed through intact skin. Some individuals with very sensitive skin may experience mild irritation, but this is rare.

Who should be careful with Magnesium Aluminum Hydroxide Carbonate?

Those with very dry or dehydrated skin who prefer hydrating formulas

Research sources

Cosmetic Ingredient Review (CIR) Safety AssessmentOpenEU CosIng DatabaseOpenFDA Color Additive Status ListOpen

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.