What are the side effects of sweetener 952?

December 17, 2025 •

4 min read

Sweetener 952, also known as cyclamate, was banned in the US in 1970 following controversial animal studies that linked it to cancer, a move that created lasting public debate about its safety. Although many regulatory bodies worldwide have since re-approved it for use, consumers remain concerned about its potential side effects.

Quick Summary

An exploration of sweetener 952 (cyclamate), discussing its controversial history surrounding cancer concerns, its potential metabolic and digestive side effects, and why its regulatory status differs globally.

Key Points

Regulatory Controversy: Sweetener 952 (cyclamate) is banned in the US and Canada but is approved in over 130 countries, including the EU.
Cancer Link Refuted for Humans: The US ban resulted from animal studies linking cyclamate to bladder cancer, but later human studies and re-evaluations largely refuted this risk for humans at normal intake levels.
Metabolic Impact: Long-term, high-dose use of cyclamate (often with saccharin) has been linked to potential metabolic issues, including increased fasting blood glucose and HbA1c levels, particularly in diabetic individuals.
Gut and Digestive Side Effects: Cyclamate is known to alter the gut microbiome and can cause digestive symptoms like gas and bloating in some people.
Testicular Concerns in Animals: A metabolite of cyclamate, cyclohexylamine (CHA), has shown potential testicular toxicity in high-dose animal studies, but this effect has not been observed in humans at normal exposure levels.
Use in Moderation: As with many additives, experts advise consuming cyclamate in moderation and staying within the Acceptable Daily Intake (ADI) levels set by local regulatory bodies.

What is Sweetener 952?

Sweetener 952 is the food additive code for cyclamate, a synthetic, non-caloric artificial sweetener discovered in 1937. Typically sold as its sodium or calcium salt, cyclamate is approximately 30-50 times sweeter than table sugar. It is often used in combination with other artificial sweeteners, like saccharin, to create a more sugar-like taste and mask any bitter aftertaste.

The Banned and the Permitted: A Regulatory Divide

The history of cyclamate is marked by a significant regulatory divide that continues today. The most notable event occurred in 1970 when the U.S. Food and Drug Administration (FDA) banned cyclamates from food products following a 1969 study. This animal study, which fed rats a high-dose mixture of cyclamate and saccharin, suggested a link to bladder cancer. However, subsequent independent studies and re-evaluations by other international bodies, including the European Food Safety Authority (EFSA), found that cyclamate did not pose a carcinogenic risk to humans at normal consumption levels. The US ban, however, remains in effect, while cyclamates are approved and regulated for use in more than 130 countries, including the EU, Canada (as a tabletop sweetener), and Australia.

Potential Metabolic and Weight-Related Side Effects

Despite being a non-caloric sweetener often used for weight management, some research has suggested that cyclamate may have paradoxical effects on metabolism.

Blood Sugar Control: While artificial sweeteners don't directly raise blood glucose, some studies indicate potential negative impacts on glycemic control, especially with long-term use. One study showed that long-term consumption of saccharin and cyclamate mixtures correlated with increased fasting blood glucose and HbA1c levels in diabetic patients. This can lead to poorly regulated blood sugar over time, potentially due to the body's confused response to the sweet taste without the expected calories.
Weight Gain: Some animal studies suggest a link between artificial sweeteners and increased weight gain. The hypothesis is that decoupling the sweet taste from caloric intake can disrupt the brain's regulation of appetite, leading to increased overall food consumption. However, human studies on this topic have yielded conflicting results and are not conclusive.

Digestive Health and Gut Microbiome Impact

Cyclamate is not metabolized by the human body and is typically excreted unchanged. However, this passage through the digestive system is not always without consequence.

Digestive Discomfort: Some individuals report experiencing gastrointestinal issues such as bloating, gas, and stomach upset when consuming cyclamate or other artificial sweeteners, especially in larger quantities.
Altered Gut Microbiome: There is evidence that artificial sweeteners, including cyclamate, can alter the composition of the gut microbiota, the community of bacteria living in the digestive tract. While the long-term health implications of this change are still being studied, gut microbiome health is increasingly linked to overall well-being.

Controversial Cancer and Toxicity Concerns

The original reason for the US ban—potential carcinogenicity—is still a point of public concern, though it is now widely considered unfounded based on human studies. A related issue involves cyclohexylamine (CHA), a metabolite produced when certain intestinal bacteria break down cyclamate. Animal studies using very high doses of CHA reported potential testicular damage. However, these findings were based on animal models, and no human studies have confirmed this risk at normal consumption levels. Health Canada, for example, concluded in 2022 that cyclamate and CHA are not harmful to human health at typical exposure levels.

A Comparison of Popular Sweeteners


Sweetener Name	Additive Code	Sweetness (vs. Sugar)	Calories	Regulatory Status	Common Side Effects	Potential Health Concerns
Cyclamate	952	30-50x	Zero	Banned in US/Canada (food); Approved elsewhere	Digestive issues (gas, bloating)	Altered gut microbiome, controversial cancer link
Saccharin	954	300-400x	Zero	Approved widely	Bitter aftertaste, digestive issues	Past animal cancer concerns (refuted for humans), altered gut health
Sucralose (Splenda)	955	400-700x	Zero	Approved widely	Digestive symptoms, potential insulin impact	Gut dysbiosis, unstable when heated
Acesulfame K (Ace-K)	950	~200x	Zero	Approved widely	Bitter aftertaste (often blended)	Controversial links to cancer, potential metabolic risks

Precautions for Consumers

When consuming products with sweetener 952, consider these precautions:

Check Local Regulations: Be aware of the specific rules regarding cyclamate in your country. If you live in the US, you will not find it in food products.
Read Labels Carefully: Cyclamate may appear as 'cyclamate,' 'sodium cyclamate,' or E952 on ingredient lists.
Consider Combined Sweeteners: Many products combine cyclamate with other sweeteners. Research the potential side effects of all sweeteners present.
Use in Moderation: As with any food additive, moderation is key. Do not exceed the recommended acceptable daily intake (ADI) levels set by health authorities in your region.
Monitor Personal Reactions: If you experience any digestive or other adverse effects after consuming products with cyclamate, consider reducing your intake or avoiding the sweetener altogether. For example, some people have reported skin reactions.
Consult a Healthcare Professional: Individuals with underlying health conditions, especially diabetes, or pregnant people should discuss their use of artificial sweeteners with a doctor.

Conclusion

Sweetener 952 (cyclamate) has a long and controversial history, but today it is legally consumed in many parts of the world under regulated conditions. While animal studies in the past raised serious cancer concerns, subsequent re-evaluations by most global health organizations have largely discredited those findings for human consumption at typical levels. However, ongoing research and reported side effects, including potential links to metabolic dysfunction, altered gut bacteria, and digestive issues, mean that it is not without concerns. Consumers should weigh the known risks and benefits, check local food regulations, and consume cyclamate in moderation. Ultimately, a balanced and diverse diet remains the healthiest approach.

For more detailed scientific information, please visit the National Institutes of Health (NIH) website for studies on cyclamates and saccharin.

Frequently Asked Questions

The most discussed side effects of sweetener 952, or cyclamate, include potential metabolic disruptions such as impaired glucose control with long-term use and altered gut bacteria. Some people also report digestive issues like gas and bloating.

Sweetener 952 was banned in the US in 1970 following a controversial animal study from 1969 that suggested a link to bladder cancer in rats fed extremely high doses of a cyclamate-saccharin mixture. Despite later studies casting doubt on the relevance of these findings to humans, the ban remains.

Yes, sweetener 952 (cyclamate) is approved for use in over 130 countries worldwide, including the European Union, Australia, and Canada, though regulations vary.

While initial animal studies raised concerns about cancer, later re-evaluations by major health bodies like the EFSA and the FDA's own Cancer Assessment Committee have concluded there is no convincing evidence that cyclamate causes cancer in humans at typical consumption levels.

Research on the link between artificial sweeteners and weight gain is mixed. Some animal studies suggest it could paradoxically lead to weight gain by confusing the brain's appetite regulation. Human studies are inconclusive.

Cyclamate has a zero glycemic index and does not raise blood sugar immediately. However, some long-term studies have shown potential adverse effects on glycemic control and insulin resistance, making it wise for diabetics to use it in moderation and under a doctor's guidance.

Allergic reactions to cyclamate are rare, but some individuals may experience hypersensitivity symptoms such as photosensitive dermatitis (skin rash) or headaches.