Ingredient review
Yellow 5 Lake
INCI: CI 21108
A widely used synthetic yellow pigment that adds color to cosmetics but offers no skincare benefits.
In plain English
CI 21108 is a synthetic yellow pigment, also known as Yellow 5 Lake. It's a color additive that gives a bright yellow shade to makeup and personal care items. It's made by combining a dye with a metal salt (aluminum) to create a stable, water-insoluble powder that won't bleed or run in products. While it's safe for most people in the tiny amounts used, it doesn't hydrate, protect, or improve your skin in any way—it's purely for visual appeal.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Useful, but context matters
Yellow 5 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 5 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 21108 is a synthetic organic pigment classified as a 'lake' colorant. It's produced by precipitating the water-soluble dye FD&C Yellow No. 5 (Tartrazine) onto an aluminum hydroxide substrate, creating an insoluble powder that can be dispersed in oils and waxes for use in color cosmetics.
How it works
In a cosmetic product, CI 21108 is dispersed as fine particles throughout the formula. Because it's insoluble in water and oil, it stays suspended in the product and deposits onto the skin or nails when applied, providing a uniform yellow color. Its stability means it won't fade or change color easily under light or heat.
Pros
Vibrant and stable color
Provides a bright, consistent yellow hue that resists fading from light or heat, making it reliable for long-lasting makeup.
Widely accepted as safe
Approved by major regulatory bodies like the FDA and EU for use in cosmetics at low concentrations, with a long history of safe use.
Cons and cautions
No skincare benefit
This ingredient is purely cosmetic—it adds color but does not hydrate, soothe, or protect the skin in any way.
Potential allergen for some
Rarely, it can cause allergic reactions, especially in people sensitive to tartrazine (Yellow 5), leading to skin irritation or contact dermatitis.
Best for
- Anyone looking for vibrant yellow shades in makeup
- People without known sensitivities to synthetic colorants
Use caution if
- Individuals with a known allergy or sensitivity to FD&C Yellow No. 5 (tartrazine)
Usage tips
Safety summary
CI 21108 is considered safe for cosmetic use at typical low concentrations. The main concern is rare allergic reactions in individuals sensitive to tartrazine. Regulatory bodies have set purity limits to minimize impurities.
Research notes
Studies confirm low acute toxicity and skin irritation potential. Allergic contact dermatitis is rare but documented. The Cosmetic Ingredient Review (CIR) panel has deemed it safe as used in cosmetics.
Common label clues
- Typical concentration
- Very low, typically less than 1% of the formula
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (Annex IV) with restrictions on maximum concentration and purity standards.
- Common uses
- Lipsticks, Eyeshadows, Blushes, Nail polishes, Soaps
- Environmental note
- As a synthetic pigment, it is not biodegradable and may accumulate in waterways if not properly filtered during manufacturing or disposal.
Good to know
- CI 21108 is the same pigment used in some food and drug products, but it's processed differently for cosmetics.
- It's often combined with other colorants to create custom shades like peach, coral, or brown.
Common questions
What is Yellow 5 Lake in beauty products?
CI 21108 is a synthetic yellow pigment, also known as Yellow 5 Lake. It's a color additive that gives a bright yellow shade to makeup and personal care items. It's made by combining a dye with a metal salt (aluminum) to create a stable, water-insoluble powder that won't bleed or run in products. While it's safe for most people in the tiny amounts used, it doesn't hydrate, protect, or improve your skin in any way—it's purely for visual appeal.
What does Yellow 5 Lake do in a beauty product?
In a cosmetic product, CI 21108 is dispersed as fine particles throughout the formula. Because it's insoluble in water and oil, it stays suspended in the product and deposits onto the skin or nails when applied, providing a uniform yellow color. Its stability means it won't fade or change color easily under light or heat.
Is Yellow 5 Lake safe for most people?
CI 21108 is considered safe for cosmetic use at typical low concentrations. The main concern is rare allergic reactions in individuals sensitive to tartrazine. Regulatory bodies have set purity limits to minimize impurities.
Who should be careful with Yellow 5 Lake?
Individuals with a known allergy or sensitivity to FD&C Yellow No. 5 (tartrazine)
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.