Addressing the potential side effects and safety of daily oral administration of Siberian ginseng

Summary Background Supplements containing Siberian ginseng (SBG; Eleutherococcus senticosus, ‘eleuthero’) are administered to horses to maintain health and wellbeing. SBG has been reported to cause hypertension, anxiety and hypoglycaemia in other species, but there are no published reports documenting adverse events in horses. Objectives The objective of the study was to determine if the administration of a supplement containing SBG results in hypertension, hyperactivity, anxiety and/or hypoglycaemia in horses. Methods Sixteen clinically healthy adult horses, housed in stalls and randomly assigned to treated ( N = 8; pellets containing SBG, 1000 mg, fed daily for 29 days) or control ( N = 8; pellets without SBG) groups. Blood work was evaluated on days 1 and 28 after daily feeding. Blood pressure and movement in the stall were measured before and for 3 h after feeding the pellets on days 1, 14 and 28. Horses were subjected to a novel object test (NOT) on day 0, before feeding the pellets and day 29, 2 h after administering the supplement. Anxiety scores to the NOT were assigned by a masked observer. Horses were monitored daily for adverse events. Results The supplement was readily consumed by the horses and no adverse effects were seen over the treatment period. Mean systolic blood pressure was significantly ( p < 0.05) decreased in the SBG‐treated group by day 14 and 28 when compared to day 1 and on day 28 compared to controls. Anxiety scores, after the NOT, were not significantly different between groups. There were no treatment effects on heart rate, blood values, including glucose, indicators of anaemia and blood proteins, liver enzymes, kidney values, electrolytes, calcium or bodyweight. Conclusions The supplement containing Siberian ginseng (1000 mg, once daily) was readily consumed and the administration for 29 days did not cause health issues, or result in hypertension, increased anxiety or hypoglycaemia.