According to a recent scientific review, there is only limited evidence supporting the administration of herbal supplements in horses, despite their widespread use in the industry. Further, adverse events associated with herbal supplementation are an under-recognized and potentially serious issue.

Carey A. Williams, PhD, and Emily D. Lamprecht from the Equine Science Center at Rutgers, The State University of New Jersey reported that only a select few herbs have been included in peer-reviewed, published research trials performed in horses. These include:


  • Echinacea as an immune stimulant;
  • Devil’s claw (included in an herbal mixture) as an anti-inflammatory agent in osteoarthritis;
  • Flaxseed for protection against laminitis, improved cardiovascular health, and a decrease in allergic skin disease;
  • Garlic for decreasing the respiratory rate in horses with COPD;
  • Ginger during exercise to reduce recovery times.

Yucca is a popular ingredient in oral joint health supplements and is touted to decrease respiratory problems (such as chronic obstructive pulmonary disease), yet no studies evaluating this herb have been performed in the horse.

“While data supporting the use of herbal supplements has been obtained for other species, including humans, more research is needed in horses,” Williams stated. “At present, most herbal supplements are advertised and utilized based on anecdotal evidence and testimonials only.”

According to Williams, horse owners and trainers need to carefully consider both financial and safety issues when deciding whether to use an herbal supplement in their horse.

“Considering the potential side effects, the horse’s purpose, breed, age, sex, general health, reproductive status, current diet, and pharmaceutical usage should all be taken into account prior to initiating an herbal supplement regi