Celsius energy drinks contain a form of vitamin B12 called cyanocobalamin, which has the word “cyanide” in its name for a reason: the molecule does contain a single cyanide group bonded to a cobalt atom. But the amount is so vanishingly small that it poses zero toxicity risk. A can of Celsius has 6 micrograms of cyanocobalamin, and only a tiny fraction of that weight is the cyanide portion. For context, the lethal dose of ingested cyanide for a human is 100 to 200 milligrams, meaning you’d need to consume millions of cans in a single sitting to reach a dangerous level from this source alone.
Why Celsius Contains a Cyanide Compound
Cyanocobalamin is a synthetic form of vitamin B12 approved by the FDA to treat and prevent B12 deficiency. It’s the most common form of B12 used in fortified foods and energy drinks because it’s cheap to produce and holds up well under heat, which makes it stable on store shelves for long periods. The alternative forms of B12, like methylcobalamin, break down more easily and cost more to manufacture.
The “cyano” in cyanocobalamin refers to a single cyanide group (one carbon atom bonded to one nitrogen atom) attached to a central cobalt atom. As the American Chemical Society describes it, several chemical forms of vitamin B12 exist, and they differ by what’s bonded to the cobalt at the center of the molecule. In cyanocobalamin, that substituent happens to be a cyanide group.
How Your Body Handles the Cyanide
When your body processes cyanocobalamin, it strips off the cyanide group to use the active B12 portion. The freed cyanide fragment is then excreted through your kidneys in urine. This is a routine process your body handles without difficulty.
Interestingly, the relationship between B12 and cyanide works in reverse during cyanide poisoning. Doctors treat acute cyanide exposure by injecting large doses of a different B12 form called hydroxocobalamin. The hydroxocobalamin molecule binds to free cyanide ions in the blood, forming cyanocobalamin, which the kidneys then flush out. In other words, your body already treats cyanocobalamin as the safe, ready-to-excrete end product of cyanide neutralization.
Putting the Numbers in Perspective
A single can of Celsius contains 6 micrograms of cyanocobalamin. The cyanide group makes up roughly 2% of cyanocobalamin’s molecular weight, so you’re looking at about 0.12 micrograms of cyanide per can. That’s 0.00000012 grams.
The lethal dose of ingested cyanide is 100 to 200 milligrams, according to the Johns Hopkins Center for Health Security. To reach even the low end of that range from Celsius alone, you would need to drink somewhere around 800 million cans. For further comparison, common foods contain far more cyanide compounds than a B12 supplement. Apricot kernels, for example, contain 0.122 to 4.09 milligrams of cyanide per gram of kernel. A single apricot seed can contain more cyanide than tens of thousands of cans of Celsius.
Apple seeds, lima beans, and cassava also naturally contain cyanide compounds in quantities that dwarf what’s in cyanocobalamin. Your body routinely detoxifies small amounts of cyanide from food without issue.
Can Cyanocobalamin Build Up Over Time?
No. B12 is a water-soluble vitamin, so your body doesn’t stockpile it the way it does fat-soluble vitamins. When you take in more cyanocobalamin than you need, the excess is rapidly eliminated in urine. Higher doses simply get flushed out faster. There is no known overdose threshold for cyanocobalamin, and no antidote exists because one isn’t needed.
The cyanide fragment follows the same exit route. Your kidneys clear both the intact cyanocobalamin and any freed cyanide efficiently enough that accumulation isn’t a concern, even with daily consumption.
Why This Concern Keeps Coming Up
The word “cyanide” understandably triggers alarm. It’s associated with poison, and seeing it connected to something you drink every day is jarring. But chemistry is full of cases where a dangerous element becomes harmless in a different molecular context. Table salt contains chlorine, which is toxic as a gas but perfectly safe bonded to sodium. The cyanide group locked onto cobalt in cyanocobalamin is similarly neutralized by its chemical bonds, and the trace amount released during digestion is far below anything your body can’t handle.
If you still prefer to avoid cyanocobalamin entirely, look for supplements or drinks that use methylcobalamin or hydroxocobalamin as their B12 source. These forms contain no cyanide group at all. They’re less common in mass-market energy drinks due to higher cost and lower shelf stability, but they’re widely available as standalone supplements.