Ingredient review
Red 4 (CI 15800)
INCI: CI 15800
A widely used synthetic red pigment that adds color to makeup but offers no skincare benefits.
In plain English
CI 15800 is a man-made red pigment that gives a pink or red color to makeup products like lipstick, blush, and eyeshadow. It doesn't do anything for your skin beyond coloring it temporarily.
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
Red 4 (CI 15800) 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 Red 4 (CI 15800).
- 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
A synthetic organic pigment from the monoazo family, approved for use in cosmetics in many regions.
How it works
It sits on the surface of the skin or nail, reflecting light to create a visible color. It does not penetrate or interact with skin cells.
Pros
Vibrant color payoff
Delivers a strong, consistent red or pink hue that lasts well on the skin.
Formulation stability
Resists fading from light and heat, so your makeup stays true to color longer.
Cons and cautions
No skin benefit
Provides only color; it does not hydrate, protect, or improve skin texture.
Potential staining
Can leave temporary color on clothes or skin, especially in high-concentration products like lip stains.
Best for
- Anyone looking for a bright red or pink color in makeup
- Those who prefer synthetic over natural colorants
Use caution if
- Individuals with known sensitivity to azo dyes
- Those seeking skincare benefits from their color cosmetics
Usage tips
Safety summary
Generally considered safe for topical use at regulated concentrations. Rare reports of skin irritation or allergic reactions, mostly in individuals sensitive to azo dyes.
Research notes
Limited independent research on CI 15800 specifically; safety assessments rely on general azo dye studies and regulatory reviews. The Cosmetic Ingredient Review (CIR) panel has deemed it safe as used.
Common label clues
- Typical concentration
- Typically used at very low levels, often under 1%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU, and many other countries, subject to purity and concentration limits.
- Common uses
- Lipsticks, Blushes, Eye shadows, Nail polishes, Soaps
- Environmental note
- As a synthetic pigment, it is not biodegradable and may accumulate in water systems if not properly filtered during manufacturing.
Good to know
- CI 15800 is also known as D&C Red No. 4 in the US and is regulated by the FDA for use in cosmetics.
- It is not the same as Red 40 (a food dye) or other red pigments like Red 7 or Red 28.
Common questions
What is Red 4 (CI 15800) in beauty products?
CI 15800 is a man-made red pigment that gives a pink or red color to makeup products like lipstick, blush, and eyeshadow. It doesn't do anything for your skin beyond coloring it temporarily.
What does Red 4 (CI 15800) do in a beauty product?
It sits on the surface of the skin or nail, reflecting light to create a visible color. It does not penetrate or interact with skin cells.
Is Red 4 (CI 15800) safe for most people?
Generally considered safe for topical use at regulated concentrations. Rare reports of skin irritation or allergic reactions, mostly in individuals sensitive to azo dyes.
Who should be careful with Red 4 (CI 15800)?
Individuals with known sensitivity to azo dyes Those seeking skincare benefits from their color cosmetics
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.