Sodium Cyclamate

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Sodium Cyclamate


Sodium cyclamate (SO-dee-um SYE-kla-mate) is a white, crystal solid or powder with almost no odor and a very sweet taste. Its sweetening power is about 30 times that of table sugar, the standard against which artificial sweeteners are measured. Because of its sweet flavor, sodium cyclamate is used as an artificial sweetener.



Monosodium cyclohexylsulfamic acid; sodium cyclohexanesulfamate




Carbon, hydrogen, nitrogen, sulfur, oxygen, sodium


Organic salt




201.22 g/mol


265°C (509°F)


Not applicable; decomposes


Soluble in water; insoluble in most organic solvents

The cyclamate family of compounds was discovered in 1937by Michael Sveda (1912–1999), then a graduate student at the University of Illinois. Sveda was working on the development of new drugs to treat fever. The story is that Sveda was smoking while he was working in the laboratory (a practice that would not be allowed today) and, at one point, he brushed some loose threads of tobacco from his lips. As he did so, he noticed a very sweet flavor on the cigarette. Curious as to the cause of the sweetness, Sveda looked more carefully into the compounds he was studying and eventually identified the source of the sweetness as a substance belonging to a class of compounds known as cyclamates. The cyclamates are organic salts of the carboxylic acid cyclamic acid (C6H11NHSO3H). The University of Illinois received a patent for the production of cyclamates, which they eventually sold to the DuPont chemical company. DuPont, in turn, sold the patent to Abbott Laboratories, who first marketed the product in 1950. The compound rapidly became very popular as an additive for diet foods and drinks. It most formulations, it is mixed with saccharin, another artificial sweetener. Saccharin is ten times as sweet as sodium cyclamate, but it leaves a metallic aftertaste that sodium cyclamate helps to mask.

The first evidence about possible health effects of ingesting cyclamates was announced in 1969. Scientists reported that they had fed eighty rats a diet that contained large amounts of Sucaryl®, a product containing saccharin and sodium cyclamate, every day for two years. At the end of that time, twelve of the eighty rats had developed bladder cancer. Based on this study, the U.S. Food and Drug Administration (FDA) decided to ban the use of cyclamates as food additives.

The FDA's decision has long been the subject of considerable debate. Some people praise the agency for banning a substance they believe to be carcinogenic in humans as well as rats. Others feel that the evidence on which the FDA decision was based is not strong enough to require banning of the product. In light of this controversy, a number of additional studies have been conducted on the health effects of the cyclamates. In 1984, the FDA reversed its decision on the compound, having become convinced that no evidence had been produced to support the original 1969 study on which its earlier decision had been made. A year later, the National Academy of Sciences announced the results of its own review of the evidence on the cyclamates. The academy also saw no reason to ban the product as a food additive. Outside the United States, the cyclamates have generally been approved for use as an artificial sweetener.


Cyclamic acid is made by the sulfonation of cyclohexylamine. Cyclohexylamine is a six-carbon ring compound with a single amine (-NH2) group attached to it. Its formula is C6H11NH2. Sulfonation is the process by which an -SO2 group is added to a compound. Sulfonation of cyclohexylamine is accomplished with either sulfur dioxide (SO2) or sulfamic acid (HOSO2NH2).


Sodium cyclamate and calcium cyclamate are used as artificial sweeteners. Since they have no nutritional value (that is, the contain no calories), they can be used in foods and drinks designed for diabetics and dieters. The product also appeals to food processors because it is much sweeter than table sugar. One gram of sodium or calcium cyclamate is as sweet as 30 grams of table sugar, so much less is needed to make a product taste sweet. The cyclamates are also stable to heat, which means that they will not break down if foods in which they are contained are baked or boiled. The compounds have long shelf lives and are inexpensive to make.

Interesting Facts

  • Sodium cyclamate was nearly the undoing of the sports drink Gatorade. The drink was invented in the late 1960s. The inventors decided to use sodium cyclamate as a sweetener because it had less of a bitter aftertaste than saccharin. One year after Gatorade first appeared, however, the FDA banned cyclamates as food additives. The inventors quickly reformulated their product, using fructose in place of cyclamates as a sweetener. The drink went on to become an outstanding commercial success, but without the benefit of sodium cyclamate.

Words to Know

A substance that causes cancer in humans or other animals.

Cyclamates are often used in combination with table sugar and other artificial sweeteners. The combination of a cyclamate and saccharin, for example, has the benefit that the two sweeteners cancel out the bitter and metallic aftertastes that each by itself has.


"Cyclamate." Zhonga Hua Fang Da. (accessed on November 8, 2005).

"Low-Calorie Sweeteners: Cyclamate." (accessed on November 8, 2005).

"Sodium Cyclamate." Hazard Database. (accessed on November 8, 2005).

See AlsoL-Aspartyl-L-phenylalanine Methyl Ester; Saccharin; Sucrose