The use of Pimpinella species, particularly Pimpinella anisum (anise), for nausea and vomiting is primarily founded on traditional and historical medicine, especially within European, Middle Eastern, and South Asian herbal practices. Traditional systems, such as Ayurveda and Unani, have used anise seeds to soothe digestive discomfort, flatulence, and occasional nausea. Folk remedies often include anise as a carminative and mild antiemetic, added to teas or tinctures intended to calm the stomach and ease symptoms of gastrointestinal distress.

However, scientific validation for this specific application is limited. While some studies have investigated the general antispasmodic, carminative, and digestive properties of Pimpinella anisum, most research focuses on its use for dyspepsia, bloating, and flatulence, rather than direct effects on nausea or vomiting. There is a lack of robust clinical trials evaluating its efficacy for these symptoms. Isolated components, such as anethole, may have mild antiemetic effects based on in vitro or animal studies, but human data are sparse.

In summary, the rationale for using Pimpinella to help with nausea and vomiting is mostly grounded in longstanding herbal tradition, with only limited suggestive evidence from pharmacological studies and weak to moderate ethnobotanical support. Its use for this purpose should be considered as complementary and not as a primary or evidence-based intervention.