Bio-Oil is a product we're asked about regularly, mostly because it claims to tackle scars, stretch marks, and uneven skin tone, something many people are dealing with. The company maintains that it uses a “breakthrough ingredient” known as PurCellin oil. As it turns out, this oil is derived from ducks (it is the substance ducks secrete from their skin to keep their feathers waterproof), but it has absolutely no research proving it affects the skin concerns that Bio-Oil is touted as being able to treat. In fact, PurCellin oil isn’t even included on Bio-Oil’s ingredient list. Instead, you’re applying a mix of mineral oil and emollients to your skin, along with commonplace vitamins and some irritating fragrant plant oils (which is at best confusing and strangely misleading). Several irritating fragrance ingredients are included, too, all of which adds up to an unabashedly poor product that should not be taken seriously because it simply doesn’t make scars and stretch marks less apparent. All this can realistically do (beyond irritating skin) is provide some moisturizing benefit. That can help minimally if your skin is dry, but it won’t change any other aspect of scarring, nor will it improve an uneven skin tone.
Of particular concern is the lavender oil, which smells great but causes havoc on skin. Research indicates that components of lavender, specifically linalool, can be cytotoxic, which means that topical application causes skin-cell death (Source: Cell Proliferation, June 2004, pages 221–229). Lavender leaves contain camphor, which is a known skin irritant. Because the fragrance constituents in lavender oil oxidize when exposed to air, lavender oil is a pro-oxidant, and this enhanced oxidation increases its irritancy on skin (Source: Contact Dermatitis, September 2008, pages 143–150). Lavender oil is the most potent form, and even small amounts of it (0.25% or less) are problematic. Although it’s fine as an aromatherapy agent for inhalation or relaxation, it is a must to avoid in skin-care products. (Sources: Psychiatry Research, February 2007, pages 89–96; and www.naturaldatabase.com).