All Natural Herbs for Calming Horses Does your horse seem high-strung or anxious? Try our specially formulated herbs designed specifically for calming anxious and high-strung horses. Our blend of natural herbs, sooths, relaxes and calms horses. Here at Silver Lining Herbs our specially formulated herbs are designed specifically for equines. World-renowned equine veterinarians already recommend our NASC approved supplements for horses, and soon, you will be too.