Although a strong aroma is not a substantiative fact to call it synthetic, the possibility of adulteration with synthetics & artificial scents is not ruled out. Most Pure oils give us a soothing aroma, & the olfactory system of our nose is a sophisticated instrument to figure it out. Although some natural aroma is strong, they give us a calming effect rather than a headache. At the same time, we assume you don’t have allergic conditions.