Spark Biomedical, a wearable neurostimulation company, has published results from a pilot clinical trial showing that transcutaneous auricular neurostimulation (tAN) delivered through a wearable earpiece produced clinically meaningful reductions in heavy menstrual bleeding – a condition affecting more than 10 million women in the U.S.
The open-label study, funded by the National Bleeding Disorders Foundation and published in Bioelectronic Medicine, evaluated women with heavy menstrual bleeding over three menstrual cycles: one baseline cycle followed by two consecutive treatment cycles. Among women who completed the full protocol, the results included up to a 48% reduction in menstrual blood loss, a 71% reduction in cognitive symptoms like brain fog and difficulty concentrating, a 68% decrease in overall menstrual symptoms, a 62% reduction in pain-related symptoms, and 70% less extra time spent in bed due to menstrual symptoms. Treatment outcomes improved over consecutive cycles, suggesting increased benefit with continued use.
The technology (Sparrow Link) delivers gentle electrical stimulation to branches of the vagus and trigeminal nerves through the ear, targeting pathways associated with inflammation, pain perception, and hemostasis.
“We’re beginning to see clear evidence that the nervous system plays a critical role in menstrual health – and that we can safely influence it,” said co-founder and chief science officer Navid Khodaparast, PhD. “This study is an important step toward redefining how we treat heavy menstrual bleeding, moving beyond hormones and toward precise, neuromodulation-based therapies.”
Heavy menstrual bleeding is frequently normalized despite its significant impact on work productivity, physical functioning, and daily life. Existing treatments rely primarily on hormonal therapies or surgical intervention, leaving a gap for women seeking non-hormonal alternatives. This is a pilot study and an early step, but the findings represent a novel non-hormonal approach to a condition that has seen limited therapeutic innovation.
Spark’s tAN therapy has been used in over 30 clinical trials across multiple indications.
