Koru Essential Oils has made a conscious decision, both ethically and with respect to the plants themselves to never dilute any of our 5ml or 15ml stock singles or blends with fillers or carrier oils. Many companies skirt around this by using fancy scientific names for carrier oils in their products, such as Prunus amygdalus dulcis (sweet almond oil) or Caprylic/capric triglyceride (denatured coconut oil) - to name a couple. These ingredients when added to a diffuser for aromatherapy can quickly and easily ruin a diffuser...plus you're paying a whole lot for a filler in your essential oils with no aromatically therapeutic benefits to them at all. Always check the labels. Or...just buy Koru...you'll never have to wonder.