Petasines is a key extract from the plant Petasites hybridus, commonly known as butterbur. Its use in the treatment of rhinitis—especially allergic rhinitis—has a foundation in scientific evidence. Multiple randomized, double-blind, placebo-controlled trials have investigated butterbur extracts (standardized for petasines content) for their efficacy in relieving symptoms such as nasal congestion, sneezing, and itchy nose. Several studies, including a notable one published in BMJ (2002), found that butterbur was as effective as cetirizine (a common antihistamine) in reducing symptoms of hay fever, without the sedative side effects typical of some antihistamines.

The mechanism is thought to involve the inhibition of leukotriene synthesis and histamine release, both of which play key roles in the inflammatory cascade of allergic rhinitis. Systematic reviews and meta-analyses have generally found butterbur extracts to be superior to placebo and comparable to standard antihistamines for symptom control. Importantly, only petasines extracts that are free of pyrrolizidine alkaloids (PAs), which can be hepatotoxic, are recommended for medicinal use.

Despite the encouraging results, the evidence base is not perfect—many studies are small or funded by manufacturers, and long-term safety data are limited. Nonetheless, the current scientific consensus supports the efficacy of petasines-containing butterbur extracts as an option for managing rhinitis, especially in individuals seeking non-sedating alternatives to conventional antihistamines.