Quick summary
At a glance
Yellow 6, also called Sunset Yellow FCF, is a synthetic yellow-orange food dye used to make foods, drinks, medications, supplements, cosmetics, and other products look brighter.
The strongest human concern comes from broader research on synthetic food dyes and behavior in children. Yellow 6 was included in the well-known Southampton study, and a 2022 review of food-dye research concluded that synthetic dyes can negatively affect behavior and attention in some children. Yellow 6 itself has less human research than Yellow 5, which leaves more uncertainty about its long-term effects, especially in adults. Animal and laboratory studies have also raised questions about DNA damage, oxidative stress, and other biological effects.
Because Yellow 6 provides no nutritional benefit and is used primarily for appearance, we choose to avoid it when practical.
What it is
Yellow 6 is a synthetic azo dye used to create yellow, orange, and reddish-orange colors in foods, drinks, medications, supplements, cosmetics, and other products.
It is manufactured from petroleum-derived starting chemicals that are put through several controlled chemical reactions to form the final dye. One of the defining features of Yellow 6 is an azo bond, a chemical link that helps produce its strong color.
Why it is used
Yellow 6 is primarily used for appearance.
Manufacturers use it to:
make foods and drinks look brighter
create consistent coloring between batches
restore color that may be lost during processing
produce yellow-orange, orange, red-orange, brown, and other shades when combined with additional dyes
It provides no nutritional benefit.
Where it is commonly found
Yellow 6 can appear in:
candy and gummies
orange or fruit-flavored drinks
sports and energy drinks
soda and drink mixes
breakfast cereals
chips and flavored snacks
baked goods
frosting and cake decorations
gelatin desserts
ice cream and frozen desserts
cheese and cheese-flavored products
sauces and seasonings
jams and jellies
soups
vitamins and supplements
prescription and over-the-counter medications
cosmetics and personal-care products
A product does not have to look obviously orange to contain Yellow 6. It can be combined with other dyes to create different colors.
What current research says
Human research specifically isolating Yellow 6 is relatively limited, so much of what we know comes from studies of synthetic food dyes as a group.
One of the most discussed human studies is the 2007 Southampton trial, which tested mixtures of synthetic food colors and sodium benzoate in children. Sunset Yellow, or Yellow 6, was included in one of the mixtures. The researchers reported increased hyperactive behavior associated with some of the additive mixtures, although the design does not allow us to determine how much of that effect came specifically from Yellow 6.
A large 2022 review examined 27 clinical trials involving synthetic food dyes and childhood behavior. Sixteen of 25 challenge studies found some evidence of adverse behavioral effects, and 13 found statistically significant associations. The review concluded that synthetic food dyes can affect activity and attention in some children. Yellow 6 was among the dyes evaluated, although the authors noted that direct neurobehavioral research specifically on Yellow 6 remains limited.
Laboratory and animal studies have also investigated DNA damage and genotoxicity, with mixed results. A study using human blood lymphocytes found increased micronucleus formation and other signs consistent with cytotoxic and genotoxic potential after direct laboratory exposure to Sunset Yellow. Animal studies have also reported DNA or chromosomal damage under some experimental conditions. However, another mouse study found no stable genotoxic lesions in an intestinal micronucleus assay even at very high doses.
More recently, a 2026 study reported DNA strand breaks and blood-cell changes in rats exposed repeatedly to Sunset Yellow, including effects at different experimental doses. These findings add to the reasons researchers continue investigating the dye, but they do not establish that typical human dietary exposure causes the same effects.
Overall, the evidence does not establish that Yellow 6 causes serious disease in humans, but we can not be sure yet. The strongest human concern remains the broader association between synthetic food dyes and behavioral effects in some children, while questions involving DNA damage and other biological effects rely much more heavily on laboratory and animal studies.
Potential concerns or controversies
Behavior & Attention
Yellow 6 was one of the synthetic dyes included in research that found increased hyperactive behavior in some children.
A broader review of clinical trials concluded that synthetic food dyes can adversely affect activity and attention in a subset of children. However, there is much less human research isolating Yellow 6 by itself, so we cannot say how large its individual contribution may be.
This does not mean Yellow 6 causes ADHD, and it does not mean every child reacts to synthetic dyes.
Limited Human Research
One of our concerns with Yellow 6 is simply how much remains uncertain.
There is significantly more research on synthetic dyes collectively than there is on long-term Yellow 6 exposure specifically, particularly in adults.
The absence of strong human evidence does not automatically prove that there is no effect—it means the risk is not yet clearly defined.
DNA Damage & Genotoxicity
Laboratory and animal studies have produced conflicting results.
Some studies have reported DNA damage, chromosomal changes, or increased micronucleus formation after exposure to Sunset Yellow. For example, a laboratory study using human blood lymphocytes reported signs of both cytotoxicity and genotoxicity. Animal studies have also reported DNA and chromosomal effects.
However, other animal testing has not found stable genotoxic damage. A 2009 mouse study found no genotoxic effect in an intestinal micronucleus assay even at doses up to 2,000 mg/kg.
These findings do not prove that Yellow 6 causes DNA damage in humans, but the mixed evidence is enough to justify continued research rather than assuming the question is settled.
Possible Blood & Organ Effects
Some animal studies have reported changes involving blood markers and other tissues after repeated Sunset Yellow exposure.
A 2026 rat study reported dose- and time-dependent changes in blood parameters alongside evidence of DNA strand breaks after repeated exposure.
These studies cannot establish that typical human consumption causes the same effects, but they raise questions about repeated exposure that deserve further investigation.
Hypersensitivity
Older challenge studies have reported reactions such as hives or other symptoms in some individuals exposed to Sunset Yellow.
However, reactions to food dyes appear to be relatively uncommon overall, and older reviews found inconsistent evidence for clinically significant intolerance.
Regulatory Uncertainty Has Changed Over Time
When EFSA re-evaluated Sunset Yellow in 2009, it temporarily lowered the acceptable daily intake because of uncertainty involving reproductive findings in animal studies and noted that estimated exposure among some children could exceed that temporary level.
That does not mean ordinary consumption was proven harmful, but it illustrates that safety assessments can change as new evidence is evaluated.
No Nutritional Benefit
Yellow 6 is primarily used to change how a product looks.
For us, that matters. When an additive provides no nutritional value, even unresolved concerns weigh more heavily because consuming it is not necessary in the first place.
Alternative or common names
- Yellow 6 FD&C Yellow No. 6 Sunset Yellow Sunset Yellow FCF E110 C.I. 15985
Related Better Products
Relevant Better Products guides will appear here when they are connected to this ingredient.
Sources and references
Sources will be listed here when this entry receives its full editorial review.