Why Does Stevia Cause Side Effects?

Stevia leaf extract, known to most as stevia, is a natural, zero-calorie sweetener used as a sugar substitute. It is derived from the leaves of the Stevia rebaudiana plant and has been used for centuries in South America.

Though they're rare, stevia's side effects can include gastrointestinal symptoms, decreased blood pressure and blood sugar, and potential impacts on the liver. The Food and Drug Administration (FDA) considers stevia leaf extract safe for consumption, and it is unlikely to cause side effects in most people.

This article discusses the different forms of stevia and the side effects of this sugar alternative.

Image of stevia leaf and spoon of sugar on a wooden table

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Is Stevia Healthy or Not?

Stevia is a zero-calorie sweetener extracted from the Stevia rebaudiana plant. There are 11 steviol glycosides in the stevia leaf, responsible for giving stevia its sweet flavor.

Knowns vs. Unknowns

Stevia is available in a few different forms. Some of these are safe for consumption, while others have not been thoroughly evaluated for safety. Forms include:

  • Green stevia leaf is the purest form of stevia. However, that does not mean it is the healthiest. stevia leaf has not been studied enough to be considered safe for consumption, and the FDA does not approve it for use in foods.
  • Stevia leaf extract is a form of stevia made by drying the leaves of the plant, steeping them in hot water, then filtering and purifying the extract. The result is a product known as purified steviol glycosides. To meet FDA standards, stevia leaf extract must be greater than 95% steviol glycoside. Stevia leaf extract in this form is generally recognized as safe by the FDA.
  • Stevia blends include brand-name products such as Truvia and Stevia in the Raw and are more processed. They're made by combining stevia leaf extract with other sweeteners or sugar alcohols. These products are also safe to consume, though they may cause side effects in people sensitive to sugar alcohol.

Stevia is much sweeter than sugar and may be up to 250–300 times sweeter than sucrose, the molecule in table sugar. Despite this, stevia contains no calories or carbohydrates, compared to sugar which has 15 calories and 4 grams of carbohydrates per teaspoon.

Stevia may be a healthy option for those looking to lower their calorie or carbohydrate intake, such as people with type 2 diabetes. However, some studies suggest that consuming nonnutritive sweeteners such as Stevia instead of sugar does not reduce overall calorie intake or blood sugar levels.

How Does Stevia Compare to Other Zero-Calorie Sweeteners?

Another popular zero-calorie sweetener is sucralose, sold under the brand name Splenda. Sucralose is derived from sugar in a chemical process and is 400–700 times sweeter than sugar. However, animal studies have linked sucralose to cancer and disruptions to the gut microbiome.

Though research on the long-term effects of stevia is limited, there is no evidence that it causes cancer. Sucralose can be especially carcinogenic (cancer-causing) when heated, so stevia may be a healthier option for baking.

Side Effects From Stevia

Stevia does not cause side effects in most people. However, some may experience the following when consuming products sweetened with stevia:

  • Gastrointestinal symptoms: Sugar alcohols, sometimes added to stevia products, may cause nausea, vomiting, diarrhea, bloating, and abdominal pain in people who are sensitive to sugar alcohol. However, Stevia itself is not known to cause gastrointestinal issues.
  • Low blood pressure: Stevia has been shown to lower blood pressure in those with hypertension (high blood pressure). There is no evidence to suggest that stevia lowers blood pressure to dangerous levels in those with normal levels. However, those taking blood pressure–lowering medication should be aware of stevia's potential to increase the drug's effects.
  • Low blood sugar: Stevia has the potential to lower blood sugar (blood glucose), especially in those using it to replace sugar. Consuming too few carbohydrates can lead to low blood sugar, leading to headaches, dizziness, shaking, and other symptoms.
  • Liver side effects: Research on the impact of stevia on the liver is preliminary and inconclusive. One study on mice found an association between stevia and sucralose elevated liver enzymes. However, further studies on humans suggest that stevia may help reduce the markers of fatty liver disease.

Does Stevia Cause Cancer?

Early studies of stevia suggested it was linked to cancer, causing the initial FDA ban in 1991. However, subsequent research led the FDA to reverse the ban as hundreds of studies' reviews showed no increased risk of cancer linked to stevia consumption.

Dosage Amounts

Though stevia leaf extract is generally recognized as safe, the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) formed the Joint FAO/WHO Expert Committee on Food Additives (JECFA), which has set an acceptable daily intake (ADI) for consumption. The ADI is the maximum average daily intake of a substance over a person's lifetime that is expected to be safe. It is based on significant research.

Is Stevia OK to Have Every Day?

It is safe to consume stevia every day. However, the ADI for steviol is 4 milligrams (mg) per kilogram body weight per day. This amounts to about 12 mg per kilograms (kg) of Stevia extract per day. For A 150-pound person, this would amount to around 40 packets of stevia.

While that high level of consumption is not generally recommended, it demonstrates the vast volume of stevia you would need to consume for it to be considered unsafe. 


Stevia is safe for most people to use. However, since stevia can have blood pressure– and blood glucose–lowering effects, as well as diuretic effects, those taking certain medications or who have certain health conditions should talk with their healthcare provider before consuming significant quantities of Stevia.

People who may be more likely to experience side effects from stevia include people taking medications to lower blood pressure or blood glucose or those diagnosed with:

Stevia During Pregnancy and Breastfeeding

Stevia leaf extract is safe to consume when pregnant or breastfeeding. However, whole stevia leaf is not approved by the FDA and is not generally recognized as safe for consumption by anyone, especially pregnant people.


Stevia is a zero-calorie, nonnutritive sweetener made from the Stevia rebaudiana plant's leaves. While most people will not experience any side effects from consuming it, stevia blends containing sugar alcohols may cause gastrointestinal symptoms in people with sugar alcohol sensitivity.

Stevia also has blood pressure– and blood glucose–lowering effects, so people on certain medications or conditions should speak with their healthcare provider before using stevia for a prolonged period. 

A Word From Verywell

If you are concerned about the potential side effects of stevia, research shows that it is safe to consume and unlikely to cause side effects in most people. It can be hard to know what foods are healthy, with so many options available today, but following a balanced diet and enjoying sugar and other sweeteners in moderation is the best way to keep your body healthy while still enjoying the foods you love.

Frequently Asked Questions

  • Did the FDA ban stevia?

    In 1991, the FDA banned stevia over concerns that it was linked to cancer. However, the FDA reversed the ban in 1995 after a follow-up study found no connection. stevia leaf extract (greater than 95% steviol glycosides) was determined to be generally recognized as safe in 2008 by the FDA.

  • Does Stevia cause inflammation?

    Stevia is not known to cause inflammation. Some studies suggest it may have anti-inflammatory properties, though more research is needed to determine the magnitude of this effect.

  • Are the benefits of Stevia better than sugar?

    Stevia contains zero calories and carbohydrates, while sugar contains 15 calories and 4 carbohydrates per teaspoon. However, studies suggest that consuming sugar substitutes such as stevia in place of sugar does not have an impact on overall daily calories intake or blood sugar levels.

15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rebecca Valdez, MS, RDN
Rebecca Valdez is a registered dietitian nutritionist and nutrition communications consultant, passionate about food justice, equity, and sustainability.