From our Kavapedia Glossary
Heady (Brain Load)
Heady Kava describes a Kava that produces more effects on your mind than on your body. It can be, euphoria, spaciness or just a gentle uplifting to your outlook and sense of well-being. It gives you a light, clean, whimsical contentment that has a lot of cognitive, psychological and emotional effects (mental relaxation, motivation, empathy, mood uplift, etc.) An energizing, cerebral side effect often used to describe a specific strain of kava kava.
Heavy (Body Load)
Heavy Kava describes a Kava that produces more effects on your body than your mind. The effects can be felt more in your body & muscles and gives you an all-around slow & sedating experience. It can relax your muscles, usually relieve some pain, and make your body feel very heavy as you sink into the couch, along with (usually) heavy sedation.