In our serums, our carrier & essential oils are all of the highest quality, and essential oil concentration is suitable for all skin types including those with sensitive skin. As with any new product, we recommend patch testing on a small section of skin. In fact, our skincare range has been created specifically for people who have had reactions or damage from synthetic or "natural" products. Our range expresses the true definition of purity and high quality in skincare. As a rule, properly distilled & extracted botanicals and hydrosols are very gentle and are unlikely to cause any adverse reactions.