Open any moisturizer and the first thing you notice is the smell. It is there because it sells: a product that smells like nothing feels like it does nothing. But fragrance, whether synthetic or distilled from a plant, is the single most common cause of contact irritation in cosmetics. Most people tolerate it. A significant minority react, often mildly, often without noticing the connection.
On lighter skin a mild reaction is a passing redness. On deeper skin it is an instruction to the melanocytes, and the redness is followed by a mark. This is why a product can be perfectly well made, pass every safety test, and still leave a Black or brown face more uneven than it found it.
Essential oils are not the exception
Natural does not mean gentle. Citrus, mint, lavender and tea tree oils are among the most sensitizing ingredients in skincare, and the reaction they cause is identical to the one caused by a synthetic perfume. We leave them out for the same reason.
What a product should smell like
Itself. Shea has a faint nuttiness; baobab oil, almost nothing; rhassoul clay smells of wet earth for the ten minutes it is on your face. These are the smells of the ingredients doing their work, and they fade as the product sinks in. We think that is enough.