Ingredient review
Yellow 7 Lake
INCI: CI 21100
A common synthetic pigment that adds yellow color to makeup and bath products, generally considered safe for topical use.
In plain English
CI 21100 is a synthetic yellow pigment, also known as Yellow 7 Lake. It is used in cosmetics to give products a yellow hue. Think of it as a color additive that makes your lipstick or eyeshadow look yellow. It's not a nutrient or active ingredient—it's purely for color.
Review score
Safety, usefulness, and evidence
Useful in the right context, but not low-maintenance
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
Quick decision guide
Read the cautions before using
Yellow 7 Lake 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging Yellow 7 Lake.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
CI 21100 is a synthetic organic pigment derived from coal tar or petroleum sources. It is a 'lake' pigment, meaning it is made by precipitating a dye onto an insoluble base (like aluminum hydroxide) to create a stable, non-bleeding color.
How it works
In a cosmetic product, CI 21100 works by reflecting and absorbing specific wavelengths of light to produce a yellow color. It is mixed into the product base (like a lipstick or powder) and stays suspended, providing consistent color without dissolving or migrating.
Pros
Stable color
CI 21100 provides a consistent yellow shade that does not fade or change color easily, so your makeup stays looking fresh.
Widely used and tested
This pigment has a long history of use in cosmetics and is generally recognized as safe by regulatory bodies when used as directed.
Cons and cautions
Synthetic origin
Derived from petroleum or coal tar, which may be a concern for those seeking natural or eco-friendly ingredients.
Rare irritation
While very low risk, a small number of people may experience skin irritation or allergic reactions, especially on sensitive skin.
Best for
- Anyone looking for a bright yellow color in makeup
- Formulators needing a stable, non-bleeding pigment
Use caution if
- Individuals with known sensitivity to synthetic colorants
- Those seeking exclusively natural or organic products
Usage tips
Safety summary
CI 21100 is considered safe for use in cosmetics at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed similar lake pigments and found them safe for topical use. Rare allergic reactions are possible.
Research notes
Research on CI 21100 specifically is limited, but it belongs to a class of lake pigments that have been extensively studied and deemed safe for cosmetic use by regulatory agencies. No significant health concerns have been identified at typical exposure levels.
Common label clues
- Typical concentration
- Typically less than 1% in most products
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (EC) with concentration limits for certain product types. Always follow local regulations.
- Common uses
- Lipsticks, Blushes, Eyeshadows, Nail polishes, Soaps
- Environmental note
- As a synthetic pigment, its production involves petrochemicals. Some manufacturers are exploring bio-based alternatives, but CI 21100 remains common.
Good to know
- CI 21100 is approved for use in cosmetics in the US, EU, and many other regions.
- It is often combined with other pigments to create custom shades.
Common questions
What is Yellow 7 Lake in beauty products?
CI 21100 is a synthetic yellow pigment, also known as Yellow 7 Lake. It is used in cosmetics to give products a yellow hue. Think of it as a color additive that makes your lipstick or eyeshadow look yellow. It's not a nutrient or active ingredient—it's purely for color.
What does Yellow 7 Lake do in a beauty product?
In a cosmetic product, CI 21100 works by reflecting and absorbing specific wavelengths of light to produce a yellow color. It is mixed into the product base (like a lipstick or powder) and stays suspended, providing consistent color without dissolving or migrating.
Is Yellow 7 Lake safe for most people?
CI 21100 is considered safe for use in cosmetics at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed similar lake pigments and found them safe for topical use. Rare allergic reactions are possible.
Who should be careful with Yellow 7 Lake?
Individuals with known sensitivity to synthetic colorants Those seeking exclusively natural or organic products
Research sources
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.