Fragrance is the most common cause of allergic contact dermatitis in skincare. This is not a contested claim. The North American Contact Dermatitis Group has tracked fragrance sensitization rates for three decades, and fragrance mix consistently ranks in the top five allergens identified by patch testing — typically responsible for 8–12% of positive patch test results across general dermatology clinics.
The sensitization is also progressive. A user who tolerates a fragrance ingredient at age 30 may develop contact dermatitis to that same ingredient at age 45. The cumulative exposure across years of leave-on product use is the driver. This is why fragrance reactions often appear with no obvious triggering change to a routine — the routine has not changed, but the exposure has accumulated past a threshold that varies by individual.
This is also why we do not use fragrance — natural or synthetic — in a single Mxt formula.
The Industry Reasoning For Fragrance
Skincare brands include fragrance for two reasons. First: many of the raw ingredients in a serum or moisturizer have an unpleasant base odor. Plant extracts, some peptides, certain oils — without fragrance, the product would smell unpleasant in the bottle. Fragrance is a corrective.
Second: a pleasant scent improves the application experience. A consumer who enjoys applying the product is more likely to apply it consistently. The compliance gain from a well-designed scent is real, and brands have research showing the magnitude.
Neither reason is about skin function. Fragrance does nothing for the skin. The trade-off is a marginal compliance improvement against a meaningful sensitization risk that grows with cumulative exposure.
The Mxt Position
We accept the marginal compliance cost. We do not use fragrance in any formula — not parfum, not perfume, not essential oils, not "natural fragrance," not the synthetic blends that get labeled as "fragrance" without further disclosure under cosmetic labeling rules. Our products smell like their active ingredients, which is sometimes mild and sometimes not, depending on the formula.
This decision is most important for users who are using retinoids, exfoliating acids, or other actives that compromise the barrier. A compromised barrier is more permeable to all topical exposures, including fragrance allergens. Many users develop fragrance sensitivities specifically during the period when they are actively trying to improve their skin with stronger actives. The combination is the worst-case exposure profile, and it is exactly the profile our customers are most often operating in.
We also do not use essential oils, even those positioned as natural alternatives. Lavender, tea tree, citrus oils, and rose oil are among the most common natural fragrance allergens. "Natural" is not a substitute for "non-sensitizing."
If you are switching to Mxt from a routine that included fragranced products, the most common feedback we get is that our formulas smell unfamiliar — not bad, just bare. That is the active ingredients, dosed at therapeutic concentrations, with nothing covering them up. We think this is the right trade.