I've taken the important points out of the rather large write-up they have provided on their website:
Contains 100% of the daily value of - B-vitamin complex - vitamin B2 (riboflavin) - niacin (vitamin B3) - pantothenic acid (vitamin B5) - pyridoxine (vitamin B6) - cobalamin (vitamin B12)
B vitamins are essential for metabolism and energy production. The B-vitamins help to support the adrenal glands. Thermogenesis utilizes hormones produced by the adrenal glands and can cause these glands to become fatigued. The addition of B-vitamins helps to nourish the adrenal glands. Also contains: Biotin - A key nutrient that functions in metabolism and helps break down the fats and proteins you eat into energy.
Vitamin C helps support natural resistance and the proper functioning of the immune system.
Calcium is a mineral that may enhance your body's ability to burn fat as well as improve bone mineral content.
Chromium - A mineral that has been added to help control hunger and to normalize insulin levels.
Celsius Thermogenic Proprietary Blend includes: (this is what actually makes Celsius work, i.e. burn calories)
Green Tea Extract with EGCG - Green tea and green tea extracts have been shown to have positive effects on metabolism and antioxidant activity. EGCG is one of the important components of Green Tea Extract.
Caffeine - The most commonly consumed drug in the world. Naturally occurring in a variety of popular beverages to food supplement products people use everyday, caffeine has proven to be truly safe and effective. Most known for its ability to reduce fatigue and enhance alertness, caffeine has also been clinically tested as a metabolic accelerator and renowned for its thermogenic effects. Clinical trials have shown increases in metabolic rate after caffeine ingestion. Research also shows caffeine is absorbed by the body better in liquid form than pill form and takes only 15-20 minutes to get into your blood and begin working. Celsius delivers beyond the benefits of energy and caloric burning. Caffeine is also popular among sports enthusiasts, because it improves performance and endurance during long exercise and enhances short-term, high intensity athletic performance.
Guarana - A natural source of caffeine found in food supplements. Our guarana extract is derived from the seeds of the plant. Indigenous Amazonian people used guarana as a stimulant and tonic long before the first European explorers arrived. In addition to caffeine, guarana contains large amounts of tannins that have antioxidant activity.
Ginger Extract - The gingerols are the plant components of ginger that impart a warm, spicy taste. Ginger exerts positive effects on the digestive, cardiovascular and central nervous systems.
Taurine - A conditionally essential amino acid, found readily throughout the body; in the central nervous system, skeletal muscle and both the brain and the heart. Taurine may enhance protein synthesis via its effects on cellular hydration.
Glucoronolactone - A natural metabolite derived from sugar (i.e. glucose) that provides the body with a quick energy boost.