Stevia

What it is

Steviol glycosides are natural sweet compounds from the leaves of Stevia rebaudiana, a plant native to parts of South America. They are reported to be 200 to 400 times sweeter than table sugar and provide sweet taste with no calories. Gut bacteria break the glycosides down to steviol, which is absorbed.

What the research says

Stevia is used to replace sugar. A 2024 meta-analysis of 12 RCTs (871 people) found a small drop in fasting blood glucose (about 4 mg/dL) and no change in HbA1c, with low overall quality of evidence. A 2015 meta-analysis found no significant effect on systolic blood pressure and small, heterogeneous effects elsewhere. A 12-week trial found no change in glucose or insulin responses. The WHO (2023) advises against using any non-sugar sweetener, stevia included, for weight control, while critics argue the randomised trials were given too little weight. Reported adverse events in trials include abdominal fullness, epigastric pain and dizziness.

Evidence grade: Limited evidence.

What goes wrong

Adverse events reported across steviol glycoside trials included abdominal fullness, epigastric pain and dizziness (rates not given in the abstract). (Source 1)

• Meta-analysis, Low certainty.
• Size: 9 studies, 756 participants.
• Who: adults in RCTs.
• How long: varied.
• Result: rates not reported in the abstract.
• Funding: not stated.

Adverse events included abdominal fullness, epigastric pain, and dizziness.

WHO guideline (15 May 2023), covering stevia and stevia derivatives, reports its systematic review suggested possible undesirable effects of long-term non-sugar sweetener use, based largely on observational data; this is association, not proven cause, and is not stevia-specific. (Source 2)

• Official position, Low certainty.
• Size: not stated.
• Who: adults.
• How long: long-term use.
• Result: increased risk of type 2 diabetes, cardiovascular diseases and mortality in adults (associations); conditional recommendation.
• Funding: independent (WHO)

increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults

EFSA (2024) estimated that with the proposed extended uses the highest 95th-percentile exposures would be 4.1 mg/kg bw per day in infants and 6.9 in toddlers, both above the 4 mg/kg ADI, and it declined to raise the ADI. (Source 3)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: infants and toddlers (exposure modelling)
• How long: chronic exposure.
• Result: P95 exposure 4.1 (infants) and 6.9 (toddlers) mg/kg bw per day against an ADI of 4 mg/kg bw per day; both exceed it, the infant figure only marginally.
• Funding: government (EU agency)

the highest 95th percentiles of exposure are 4.1 and 6.9 mg/kg bw per day for infants and toddlers, respectively

US FDA (page updated 27 Feb 2025): stevia leaf and crude stevia extracts are not GRAS and may not be imported for use as sweeteners; only high-purity steviol glycosides have unquestioned GRAS notices. (Source 4)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: US consumers.
• How long: not applicable.
• Result: regulatory distinction between whole-leaf/crude extracts and high-purity (95% minimum) steviol glycosides.
• Funding: government.

The use of stevia leaf and crude stevia extracts is not considered GRAS, and their import into the U.S. is not permitted for use as sweeteners.

What the evidence supports

A 2024 meta-analysis of 12 RCTs found steviol glycosides lowered fasting blood glucose slightly versus controls, with low overall quality of evidence. (Source 5)

• Meta-analysis, Low certainty.
• Size: 871 participants across 12 RCTs.
• Who: adults.
• How long: varied across trials.
• Result: FBG MD -4.10 mg/dL (95% CI -6.55 to -1.65)
• Funding: not stated.

A significant effect of SGs on FBG (MD = −4.10 mg dl−1, 95% CI −6.55 to −1.65) was found

What the evidence does not support

The same meta-analysis found no significant difference in HbA1c. (Source 5)

• Meta-analysis, Low certainty.
• Size: 871 participants across 12 RCTs.
• Who: adults.
• How long: varied.
• Result: HbA1c MD 0.01% (95% CI -0.12% to 0.13%)
• Funding: not stated.

no significant difference in HbA1c (MD = 0.01%, 95% CI −0.12% to 0.13%) was observed between SGs and controls

A 2015 meta-analysis of RCTs found no significant difference in systolic blood pressure between steviol glycoside and placebo. (Source 1)

• Meta-analysis, Low certainty.
• Size: 9 studies, 756 participants.
• Who: adults in randomised clinical trials.
• How long: varied.
• Result: SBP MD -2.98 mm Hg (-6.23 to 0.27)
• Funding: independent (Oxford authors; not stated in text recorded)

Meta-analysis revealed a non-significant difference in systolic blood pressure between steviol glycoside and placebo

The 2015 meta-analysis concluded rebaudioside A does not appear to affect blood pressure or cardiovascular risk factors; reporting quality varied. (Source 1)

• Meta-analysis, Low certainty.
• Size: 9 studies, 756 participants.
• Who: adults.
• How long: varied.
• Result: no significant effect for rebaudioside A.
• Funding: not stated.

Rebaudioside A does not appear to have any significant effects on blood pressure or cardiovascular risk factors.

In a 12-week open-label RCT in 28 healthy adults, daily stevia did not change glucose or insulin responses, though the stevia group maintained weight while controls gained. (Source 6)

• Randomized trial, Low certainty.
• Size: 28 healthy adults.
• Who: healthy lean adults aged about 25.
• How long: 12 weeks.
• Result: no significant glucose/insulin difference; weight change -0.22 kg (95% CI -0.96, 0.51) stevia vs +0.89 kg (0.16, 1.63) control, p=0.026.
• Funding: independent (N8 AgriFood award, BBSRC)

There was no significant difference in the glucose or insulin responses.

In a 4-week double-blind RCT funded by a stevia manufacturer, a stevia-sweetened beverage at 25% of the ADI had no significant effects on the gut microbiome versus sucrose. (Source 7)

• Randomized trial, Low certainty.
• Size: 59 healthy adults.
• Who: healthy adults.
• How long: 4 weeks plus 4-week washout.
• Result: no significant effects on microbiome composition or short-chain fatty acids.
• Funding: industry-funded (Cargill, a stevia manufacturer; three authors employed by Cargill)

Daily consumption of a beverage sweetened with 25% of the ADI of stevia for 4 weeks had no significant effects

Where the research disagrees

Whether non-sugar sweeteners including stevia should be used for weight control

• World Health Organization, guideline of 15 May 2023, systematic review of RCTs and observational studies; conditional recommendation: "recommends against the use of NSS to control body weight or reduce the risk of noncommunicable diseases (NCDs)" (Source 2)
• Authors of a 2023 commentary in the European Journal of Clinical Nutrition, argument that RCT evidence of weight benefit should outweigh observational associations: "Randomization allows confounding factors to be randomly distributed, making it possible to establish a causal relationship." (Source 8)

How much

• Reference intake: No reference intake exists; steviol glycosides are a non-nutritive sweetener with no calories. (Source 6)
• Upper limit: EFSA (2024) kept the acceptable daily intake (ADI) at 4 mg/kg body weight per day, expressed as steviol equivalents. (Source 3)
• Studied: Beverage sweetened with 25% of the stevia ADI daily for 4 weeks. (Source 7)
• Studied: A stevia extract consumed daily for 12 weeks by healthy adults. (Source 6)

A common belief, and what the research shows

The belief: Stevia is proven to lower blood sugar and help people with diabetes.

What the research shows: The 2024 meta-analysis found a small fasting glucose drop but "no significant difference in HbA1c (MD = 0.01%, 95% CI −0.12% to 0.13%) was observed between SGs and controls", and "The whole quality of evidence was rated as low."

Questions and answers

What is it?

Stevia sweeteners are purified steviol glycosides taken from the leaves of the stevia plant, which grows in South America. They taste far sweeter than sugar. (Source 4)

What does it do in the body?

Stevia gives sweet taste without calories. It is not absorbed intact: gut bacteria break it down to steviol, which the body then absorbs. (Source 9)

Is it good or bad for you?

Within the ADI, regulators consider high-purity steviol glycosides acceptable. Trials show at most small effects on fasting glucose and none on HbA1c, and the evidence is low quality. The WHO advises against relying on any non-sugar sweetener for weight control. (Source 5)

How do you get more of it?

People consume steviol glycosides in tabletop sweeteners and sweetened foods and drinks. In the US these are high-purity (at least 95%) preparations; trials gave daily stevia extract or stevia-sweetened drinks. (Source 4)

If it is harmful, what reduces it?

Stevia is not something the body stores. The concern regulators track is intake above the ADI of 4 mg/kg body weight per day, which modelling suggests toddlers could exceed with expanded uses; lower intake reduces exposure. (Source 3)

Why might someone be low in it or missing it?

Does not apply. Stevia is a sweetener, not a nutrient, so no one is deficient in it. (Source 6)

Which whole foods contain it or feed it?

The stevia leaf is the only natural source, but in the US the leaf and crude extracts are not permitted as sweeteners; steviol glycosides reach people mostly through sweetened products. (Source 4)

What happens if you do not have it?

Nothing. Stevia provides no calories or essential nutrients, so not consuming it has no known health consequence. (Source 6)

How can you test for it?

No clinical test for stevia intake or status exists in the literature we searched. (Source 9)

We searched: Web searches for steviol glycoside systematic reviews, trials, EFSA and FDA documents; none describe a clinical test.

References

1. European Journal of Preventive Cardiology. Effect of the natural sweetener, steviol glycoside, on cardiovascular risk factors: a systematic review and meta-analysis of randomised clinical trials. 2015. PMID 25412840, DOI 10.1177/2047487314560663. Read the source
2. World Health Organization. WHO advises not to use non-sugar sweeteners for weight control in newly released guideline (news release, 15 May 2023). 2023. Read the source
3. EFSA Journal. Scientific opinion on the extension of the authorisation of use of the food additive steviol glycosides (E 960a–d) and the modification of the acceptable daily intake (ADI) for steviol. 2024. DOI 10.2903/j.efsa.2024.9045. Read the source
4. US Food and Drug Administration. Aspartame and Other Sweeteners in Food. 2025. Read the source
5. Food & Function (RSC). Effect of steviol glycosides as natural sweeteners on glucose metabolism in adult participants. 2024. DOI 10.1039/d3fo04695h. Read the source
6. Nutrients (MDPI). Effects of the Daily Consumption of Stevia on Glucose Homeostasis, Body Weight, and Energy Intake: A Randomised Open-Label 12-Week Trial in Healthy Adults. 2020. DOI 10.3390/nu12103049. Read the source
7. The Journal of Nutrition. Comparison of a Daily Steviol Glycoside Beverage compared with a Sucrose Beverage for Four Weeks on Gut Microbiome in Healthy Adults. 2024. DOI 10.1016/j.tjnut.2024.01.032. Read the source
8. European Journal of Clinical Nutrition. WHO guideline on the use of non-sugar sweeteners: a need for reconsideration. 2023. DOI 10.1038/s41430-023-01314-7. Read the source
9. Microorganisms (MDPI). The Effects of Stevia Consumption on Gut Bacteria: Friend or Foe?. 2022. DOI 10.3390/microorganisms10040744. Read the source