A curated collection of 100% pure essential oils, and never include additives, bases, fillers or synthetics.. We do this to create what is called a Synergy Blend, which creates a combined effect that is more targeted to an individual need than what a single essential oil might be, exquisitely crafted for a specific purpose. The Herbal Toad's Synergy Blends include essential oils that contain the therapeutic and medicinal properties necessary for specific purposes.