Drug & supplement interaction

Stevia + Cephalexin

Cephalexin brand names: Keflex, Keftab, Cephalex, Lexin.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Stevia and Cephalexin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Stevia and Cephalexin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cephalexin and Stevia in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Stevia safety at a glance

Stevia overall Generally safe Purified stevia sweeteners are generally recognized as safe in typical food amounts.
Pregnancy Use caution Purified stevia in food amounts is likely acceptable, but whole-leaf or supplement doses are not well studied, so use caution.
Breastfeeding Use caution Food amounts of purified stevia are probably fine, but high-dose supplements lack safety data, so use caution.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cephalexin and Stevia? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cephalexin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cephalexin is filed under 7 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Stevia has documented interactions with 3 drug classes — the most serious being lithium (moderate), antidiabetes drugs (minor) and antihypertensive drugs (minor) — and none of Cephalexin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Stevia Does Interact With Other Medications

Stevia has 1 moderate, 258 minor known drug interactions in our database — Cephalexin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 1 Minor 258 No known interaction 2,571 (incl. Cephalexin)
Taking anything else?

Check Another of Your Medications Against Stevia

Covers the 2,830 medications we’ve checked against Stevia. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Stevia and Cephalexin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • An allergic reaction Worth acting on Additional detail

    Stevia

    “Orally, stevia and steviol glycosides appear to be well tolerated. Most minor adverse effects seem to resolve after the first week of use.

    Most Common Adverse Effects:

    Abdominal bloating, dizziness, headache, myalgia, nausea, and numbness.

    Serious Adverse Effects (Rare):

    Allergic reactions.”

    Stevia · Natural Medicines adverse-effect record, reported in cluster headache.

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Dizziness / Headache Additional detail

    Stevia

    “Orally, stevia and steviol glycosides may cause headache, dizziness, and numbness.”

    Stevia · Natural Medicines adverse-effect record, reported in cluster headache.

    2 sources cited
    1. 11809. Hsieh MH, Chan P, Sue YM, et al. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study. Clin Ther 2003;25:2797-808. PubMed
    2. 11810. Chan P, Tomlinson B, Chen YJ, et al. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol 2000;50:215-20. PubMed

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Nausea Additional detail

    Stevia

    “Orally, stevia and steviol glycosides such as stevioside, can cause gastrointestinal adverse effects such as abdominal fullness and nausea. However, these generally resolve after the first week of use.”

    Stevia · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    3 sources cited
    1. 11809. Hsieh MH, Chan P, Sue YM, et al. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study. Clin Ther 2003;25:2797-808. PubMed
    2. 11810. Chan P, Tomlinson B, Chen YJ, et al. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol 2000;50:215-20. PubMed
    3. 113005. Almiron-Roig E, Navas-Carretero S, Castelnuovo G, et al. Impact of acute consumption of beverages containing plant-based or alternative sweetener blends on postprandial appetite, food intake, metabolism, and gastro-intestinal symptoms: Results of the SWEE

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

Reported for Stevia but not commonly for Cephalexin: bloating or gas, numbness or tingling and muscle pain.

Effects for Cephalexin come from the ADVERSE REACTIONS section of its FDA label; effects for Stevia come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Stevia or Cephalexin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Stevia or Cephalexin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Cephalexin

This page covers Stevia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cephalexin page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 47 moderate · 11 minor.

From our pharmacist’s overview on the Cephalexin page

“Cephalexin (Keflex) is one of the most commonly prescribed oral antibiotics, usually for skin and urinary infections, and its supplement list warrants genuine care rather than a quick skim. Three of the 61 ingredients on file rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Cephalexin interaction page

One more smart check

Taking Stevia as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,899 real supplement products containing Stevia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Stevia. Even though Stevia itself has no known interaction with Cephalexin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Stevia and Cephalexin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Stevia
Top 10%

#134 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cephalexin
Top 5%

#69 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Stevia reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Stevia and Cephalexin records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Stevia

What is Stevia?

  • Sugar substitute / sweetener
  • Blood sugar support in diabetes
  • Weight management
  • Blood pressure support
  • Reducing calorie intake

Stevia is a plant-based, calorie-free sweetener that is widely used as a sugar alternative and is considered safe in normal food amounts by major regulators. Purified stevia extracts have a good safety record, but evidence for medicinal benefits like lowering blood sugar or blood pressure is limited. Talk to your pharmacist or doctor before using stevia supplements for any health condition.

Stevia rebaudiana · Asteraceae · Leaves · Powder, liquid drops, tablets, granules, tea, and purified extracts (such as rebaudioside A and stevioside)

An interaction check asks whether these two react with each other — it does not ask whether Stevia is a good idea for someone in your situation. Here is what our Stevia record says about it on its own.

Stevia: dosing

There is no standard medicinal dose of stevia. As a sweetener, the right amount is simply enough to reach the sweetness you like, and a little goes a long way because it is much sweeter than sugar.For tabletop and food products, follow the directions on the label and stay within the recommended daily intake.

From our Stevia monograph — the full record covers uses, side effects and every documented interaction.

Read the full Stevia monograph & all interactions
Medication

About Cephalexin

What Is Cephalexin Used For?

Brand names: Keflex, Keftab, Cephalex, Lexin

Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis.

It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Most-Reported Side Effects for Cephalexin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 2,157 reports
Renal failure 1,558 reports
Acute kidney injury 1,550 reports
Diarrhea 1,405 reports
Fatigue 1,303 reports
See full Cephalexin drug information
Keep checking

Other Drugs & Stevia

Browse every other medication we’ve checked against Stevia — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
1Moderate
258Minor
2,570No known interaction
1 Moderate 258 Minor 2,570 No interaction
Moderate

1 interaction

Minor

258 interactions

Showing 60 of 258 minor interactions — see all 258 on the Stevia page.

No interaction 2,570 drugs checked — show the list

We also checked Stevia against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,570 medications checked with no known interaction — see the full Stevia list.

See the full Stevia interactions page
See every supplement checked against Cephalexin, ranked by severity
Evidence & sources

Stevia References

The 10 references that drive our Stevia monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Chan P, Xu DY, Liu JC, et al. The effect of stevioside on blood pressure and plasma catecholamines in spontaneously hypertensive rats. Life Sci 1998;63:1679-84. PubMed
  2. Melis MS. A crude extract of Stevia rebaudiana increases the renal plasma flow of normal and hypertensive rats. Braz J Med Biol Res 1996;29:669-75.
  3. Melis MS. Chronic administration of aqueous extract of Stevia rebaudiana in rats: renal effects. J Ethnopharmacol 1995;47:129-34. PubMed
  4. Melis MS, Sainati AR. Effect of calcium and verapamil on renal function of rats during treatment with stevioside. J Ethnopharmacol 1991;33:257-622. PubMed
  5. Hsieh MH, Chan P, Sue YM, et al. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study. Clin Ther 2003;25:2797-808. PubMed
  6. Chan P, Tomlinson B, Chen YJ, et al. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol 2000;50:215-20. PubMed
  7. Gregersen S, Jeppesen PB, Holst JJ, Hermansen K. Antihyperglycemic effects of stevioside in type 2 diabetic subjects. Metabolism 2004;53:73-6. PubMed
  8. Barriocanal LA, Palacios M, Benitez G, et al. Apparent lack of pharmacological effect of steviol glycosides used as sweeteners in humans. A pilot study of repeated exposures in some normotensive and hypotensive individuals and in Type 1 and Type 2 diabeti
  9. Ferri LA, Alves-Do-Prado W, Yamada SS, et al. Investigation of the antihypertensive effect of oral crude stevioside in patients with mild essential hypertension. Phytother Res 2006;20:732-6. PubMed
  10. Almiron-Roig E, Navas-Carretero S, Castelnuovo G, et al. Impact of acute consumption of beverages containing plant-based or alternative sweetener blends on postprandial appetite, food intake, metabolism, and gastro-intestinal symptoms: Results of the SWEE

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Stevia and Cephalexin Together: Common Questions

Is it safe to take Stevia with Cephalexin?
We do not list a known interaction between Stevia and Cephalexin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Stevia and Cephalexin have any of the same side effects?
Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Stevia and Cephalexin combination checked?
Interactions in our licensed database are recorded against drug classes. Cephalexin is filed under 7 classifications, and Stevia has documented interactions with 3 drug classes — none of Cephalexin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Stevia interact with any other medications?
Yes. Stevia has 259 documented drug interactions in our database — Cephalexin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Cephalexin interact with any supplements?
Yes. Cephalexin has documented interactions with 61 supplements in our database — Stevia is not one of them. The Cephalexin interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Stevia monograph Uses, safety profile, and every drug interaction in one place Cephalexin drug information The full plain-English guide to this medication Cephalexin supplement interactions Every supplement checked against Cephalexin, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Cephalexin and Stevia?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.