What is the Controversy About Stevia and Its Safety?

December 26, 2025 •

4 min read

While widely popular as a sugar substitute, the journey of stevia from plant to packet is fraught with regulatory and health debates. The controversy about stevia centers on the stark distinction between its raw leaf form, which remains unapproved, and the highly refined extracts deemed safe for consumption by food agencies.

Quick Summary

The stevia controversy stems from differing regulatory statuses for crude versus refined extracts, questionable 'natural' labeling, and ongoing debates about taste and long-term health effects stemming from mixed study results.

Key Points

Refined vs. Crude: The FDA has approved highly purified steviol glycosides (like Reb-A) as safe food additives, but not the whole stevia leaf or crude extracts.
'Natural' Debate: Despite its plant origin, commercially sold stevia is a highly processed and refined extract, leading to a debate over the accuracy of its "natural" label.
Added Ingredients: To mask a bitter aftertaste, manufacturers often blend stevia with sugar alcohols (like erythritol) and fillers, which have their own associated health concerns.
Health Questions: While deemed safe by major health organizations, some studies have raised preliminary questions about stevia's potential effects on gut bacteria and hormones, though results are mixed.
Medication Interactions: Stevia can interact with certain medications, particularly those for blood pressure and diabetes, necessitating caution and medical advice for those affected.
Historical Scare: An initial scare linking stevia to cancer was debunked by subsequent studies, but the history contributes to public skepticism.

The Regulatory Maze: Crude vs. Refined Stevia

One of the most significant points in the controversy about stevia is the difference in regulatory status between the whole stevia leaf and its highly purified extracts. For years, the U.S. Food and Drug Administration (FDA) held a firm stance against the use of whole-leaf stevia and crude stevia extracts in food products. Early animal studies raised concerns about potential health risks, although these findings were later refuted or deemed non-applicable to humans.

In 2008, a landmark decision changed the market for stevia. The FDA granted "Generally Recognized As Safe" (GRAS) status to highly purified steviol glycosides, such as rebaudioside A (Reb-A). This decision allowed these refined extracts to be used as sweeteners in mainstream food and beverages. However, the regulatory approval explicitly does not extend to the whole stevia leaf or less-processed crude extracts, which the FDA still considers to lack sufficient toxicological information. This regulatory distinction is central to the confusion and debate surrounding the sweetener.

The 'Natural' vs. Processed Paradox

Many consumers are drawn to stevia because it is marketed as a "natural" plant-derived sweetener. However, the product found on grocery store shelves, under brand names like Truvia or PureVia, is a far cry from the raw leaf. The commercially available extracts are the result of an intensive, multi-step filtration and purification process.

This gap between perception and reality is a major source of the controversy about stevia. Critics argue that referring to a highly refined product as simply "natural" is misleading to the public. They contend that the label hides the industrial-scale processing required to produce the final powder or liquid, which often includes other ingredients.

Taste and the Problem with Blends

Another point of contention is stevia's taste profile. While incredibly sweet (200-400 times sweeter than sugar), the pure extract can have a lingering, bitter, or licorice-like aftertaste that many consumers find unpleasant. To overcome this, many stevia products are not just stevia. Manufacturers create blends that include other sweeteners and fillers to improve the flavor and mouthfeel.

Commonly added ingredients include:

Sugar alcohols: Such as erythritol, which can cause digestive issues like bloating and diarrhea in some people when consumed in large amounts. A recent study also linked erythritol to an increased risk of heart attack and stroke, further fueling the controversy.
Other carbohydrates: Dextrose and maltodextrin, which are starches that can add small amounts of carbs and calories.
Natural flavors: A catch-all term for other ingredients that can be highly processed themselves, leading to questions about the product's overall "naturalness".

These added ingredients mean that any adverse reactions, from stomach upset to metabolic concerns, may not be due to the stevia extract itself but to other components of the product. This complicates health research and public perception.

Health Concerns and Scientific Scrutiny

Despite being labeled GRAS by the FDA, the long-term health effects of high-purity stevia are still under investigation, and some studies have raised concerns:

Gut Microbiome Disruption: Some animal and human studies have shown a potential link between non-nutritive sweeteners, including stevia, and a disruption of the beneficial bacteria in the gut. A 2019 study suggested that this disruption could lead to glucose intolerance. However, a more recent 2024 review found that it's unlikely stevia harms gut health based on current evidence.
Endocrine Disruption: Steviol glycosides have a molecular structure similar to steroid hormones, leading to theoretical concerns about interference with hormone production. A 2016 study found increased progesterone production in human sperm cells exposed to steviol, though more research is needed to determine relevance in humans.
Blood Pressure and Drug Interactions: Stevia has been shown to lower blood pressure, which can be a concern for individuals on blood pressure-lowering medication. It can also interact with diabetes medications by potentially lowering blood sugar too much.

Comparative Analysis: Stevia Products vs. Natural Sweeteners

To understand the nuances of the stevia controversy, it is helpful to compare the two main forms and how they stack up against other natural sweeteners.


Feature	Highly Purified Steviol Glycosides (e.g., Reb-A)	Crude Stevia Extracts / Whole Leaf	Other Natural Sweeteners (e.g., Honey, Maple Syrup)
Regulatory Status	Approved as GRAS food additive by FDA.	Not approved as food additive by FDA, lack safety info.	Varies, but widely recognized as food items.
Purity & Processing	High; involves extensive refining and purification.	Low; dried and crushed leaf or simple extraction.	Minimal processing, natural form.
Sweetness Potency	200-400x sweeter than sugar.	10-15x sweeter than sugar.	Comparable to or slightly sweeter than sugar.
Taste Profile	Blended to reduce bitter/licorice aftertaste.	Pronounced bitter or licorice-like aftertaste.	Distinct flavor profiles, not just sweetness.
Associated Concerns	Gut health, hormone disruption (speculative), mixed studies.	Kidney, cardiovascular, and reproductive system issues (historical concern, still noted by FDA).	High sugar content, calorie intake.

Conclusion

The controversy about stevia is complex, multifaceted, and not a simple verdict of 'safe' or 'unsafe'. It is driven by the significant regulatory difference between purified stevia extracts and crude, whole-leaf versions, the marketing of a highly processed product as "natural," and ongoing scientific inquiry into its long-term health effects. While regulatory bodies like the FDA and WHO consider purified steviol glycosides safe within an Acceptable Daily Intake, questions remain, particularly regarding interactions with other blended ingredients and potential effects on the gut microbiome and endocrine system. For consumers, being aware of these distinctions and understanding the ingredient list is essential to make an informed choice. Ultimately, as with any food, moderation is key, and personal consultation with a healthcare provider is recommended for those with existing health conditions or on medication.

For more information on artificial and natural sweeteners, visit the Center for Science in the Public Interest.

Frequently Asked Questions

The U.S. Food and Drug Administration (FDA) initially banned stevia in 1991 over concerns stemming from early studies that suggested a possible link to cancer, though later research refuted these initial findings.

No. The FDA has only granted 'Generally Recognized As Safe' (GRAS) status to highly purified steviol glycosides, such as Rebaudioside A. The whole stevia leaf and crude extracts are not approved for use as a food additive.

Raw stevia is the unprocessed leaf, while commercial stevia products are highly refined and purified extracts of the steviol glycosides found in the leaf. It is this processing that removes the bitter aftertaste and makes it palatable for widespread use.

While pure, highly refined stevia is less likely to cause issues, many commercial products are blended with sugar alcohols like erythritol. These sugar alcohols can cause gastrointestinal side effects such as bloating, gas, and diarrhea in some individuals, especially in large amounts.

Research on stevia and gut health is mixed and ongoing. While some older studies raised concerns about microbiome disruption, newer studies suggest it may not have a significant negative impact on gut bacteria, at least in the short term.

Erythritol is controversial because while it helps improve the taste of stevia products, recent research has indicated a possible link between erythritol consumption and an increased risk of heart attack and stroke.

Purified stevia is considered safe in moderation for most people. However, individuals on certain medications, particularly for diabetes or high blood pressure, should consult a doctor before use due to potential drug interactions.