Piper Methysticum Leaf/Root/Stem Extract
Piper Methysticum Leaf/Root/Stem Extract is derived from the leaves, roots, and stems of kava kava (Piper methysticum, Piperaceae), a crop native to the western Pacific. It is listed under CAS # 84696-40-2 and EC # 283-648-9. Its official CosIng function is skin conditioning. It is also known as Kava Kava Extract.
The ingredient has been noted to possess some analgesic (painkiller) properties. Beyond this, the available data are considered insufficient to broadly support its safety or efficacy in cosmetic applications, per a 2009 safety assessment published in the International Journal of Toxicology.
According to Paula's Choice (as cited by the source), this ingredient can cause skin irritation. A 2009 safety assessment concluded that "the available data are insufficient to support the safety of these ingredients in cosmetics," raising concerns about its use in topical products.
