The fragrance debate in skincare often gets reduced to a simple story: synthetic fragrance bad, natural fragrance fine. If you’ve done any reading on sensitive skin, you’ve probably seen this framing. It’s incomplete, and for people making decisions about what to put on reactive skin, the fuller picture matters.
What fragrance actually is in cosmetics
Fragrance in a cosmetic product is a mixture of aromatic compounds that create a scent. The regulatory category is broad: in the EU, “parfum” or “fragrance” on an ingredient list can refer to mixtures of hundreds of individual chemical compounds, each with its own chemical identity and safety profile.
The EU requires disclosure of 26 specific fragrance allergens if they’re present above certain thresholds (0.001% in leave-on products, 0.01% in rinse-off products). A 2022 EU regulatory update expanded this list and imposed stricter requirements on some of the most allergenic compounds. But fragrance mixtures can contain many compounds beyond these 26 without individual disclosure.
Synthetic fragrance compounds are individually synthesised chemicals. Natural fragrance comes from essential oils, plant extracts, and other naturally derived aromatic materials. Both categories can contain potent allergens and sensitisers.
The case against synthetic fragrance
Synthetic fragrance has legitimate concerns associated with it. Some synthetic fragrance compounds, particularly musks like galaxolide and synthetic nitro-musks, have been found to persist in the environment, accumulate in fish tissue, and have raised concerns about endocrine-disrupting potential. Some, including nitromusks, have been restricted in the EU.
Phthalates, sometimes used as fragrance fixatives, have been associated with endocrine disruption and are restricted or banned in EU cosmetics. The word “fragrance” on a US label can potentially conceal phthalates that don’t need to be individually listed.
Contact allergy to synthetic fragrance compounds is common and well-documented. Cinnamal, hydroxycitronellal, and isoeugenol, all synthetic fragrance ingredients, are among the more frequent causes of cosmetic contact allergy.
The case against assuming natural fragrance is safer
Essential oils are complex mixtures of sometimes hundreds of individual aromatic compounds. Many of these compounds are identical to or structurally similar to their synthetic equivalents. Linalool, one of the EU’s 26 disclosed fragrance allergens, occurs naturally in lavender, rose, and many other botanical essential oils. It’s also produced synthetically. Both forms cause the same allergic reactions in sensitised individuals, because the immune system recognises the chemical structure, not the origin.
Limonene, another major allergen, is the dominant compound in citrus peel oils. d-limonene is completely natural and completely capable of causing contact allergy. The fact that it comes from oranges does not change its skin interaction chemistry.
Some natural fragrance ingredients have additional risks that synthetic compounds don’t. Furanocoumarins in bergamot oil (bergapten) and various citrus oils are photosensitisers: they cause phototoxic reactions when applied to skin before UV exposure. This is a risk specific to certain natural compounds and doesn’t have a direct synthetic equivalent in common use.
Oakmoss and treemoss extracts, traditional components of many classic perfume formulas, are among the most potent cosmetic allergens known and are heavily restricted in EU cosmetics. Both are completely natural.
What the research actually shows
A 2016 study in the Contact Dermatitis journal analysed data from several European dermatology patch test centres and found that natural fragrance ingredients were at least as likely to cause positive patch test reactions as synthetic ones. A subsequent analysis found that many patients with fragrance allergy reacted to both natural and synthetic fragrance-containing products.
The fundamental problem is not natural versus synthetic, it’s aromatic complexity and individual sensitisation. Whether a compound sensitises the immune system depends on its chemical structure and concentration, not its origin.
This does not mean natural fragrance ingredients are worse than synthetic ones overall. It means the binary “natural good, synthetic bad” framework doesn’t hold up when you look at the actual allergy data.
Who is most affected by fragrance in general
Fragrance allergy affects an estimated 1-2% of the general population and higher proportions of people with eczema, hand dermatitis, or occupational skin exposure. People who have had contact allergy diagnosed by patch testing consistently show high rates of fragrance sensitisation.
For most people without established fragrance sensitivity, the risk from well-formulated products at typical fragrance concentrations is low. The risk-benefit calculus changes for people with a history of skin reactions, eczema, or sensitive skin.
Fragrance-free is the safest option for sensitised skin, and here fragrance-free should mean genuinely no aromatic compounds, including essential oils. A product that replaces “synthetic fragrance” with a long list of essential oils and botanical extracts is not truly fragrance-free in the relevant sense.
Making practical choices
If you have sensitive or reactive skin, fragrance-free (genuinely free of all aromatic compounds) is the right default. If you react to fragranced products, the origin of the fragrance is less relevant than removing fragrance entirely from your routine.
If you have non-sensitive skin and simply prefer the experience of scented products, both natural and synthetic fragrance can be perfectly fine. Being aware of the 26 EU-disclosed allergens and checking for ones you know you react to is useful when selecting products.
The preference for natural fragrance as a category makes sense from a sustainability and environmental chemistry standpoint in some cases, but not as a blanket safety claim. Good skincare formulation requires honesty about what each ingredient actually does, including aromatic compounds, regardless of their origin.