Stevia Side Effects: Why I Removed It From Every Seeking Health Product

By Dr. Ben Lynch, ND Bestselling Author of Dirty Genes | Founder, Seeking Health

Key Takeaways

• If you urinate frequently, feel chronically stressed, or struggle with hydration despite doing everything right, stevia may be a significant and overlooked contributor. It is in far more products than most people realize.
• Stevia is not pharmacologically inert. Research shows it inhibits sodium reabsorption in the kidneys, causing increased water and sodium loss in urine, even at typical dietary doses.[1]
• Stevia raises cortisol. A human clinical study using whole stevia extract found significant increases in urinary and salivary cortisol after just one week of consumption.[2] Elevated cortisol suppresses ADH, the hormone that tells your kidneys to retain water. That creates a second, independent route to excess urination.
• Stevia is everywhere. Electrolytes, protein powders, vitamin C drinks, greens powders, pre-workouts, protein bars, flavored teas, kombucha, yogurt, healthy juices. Most people consuming it daily have no idea it produces these effects.
• Your genetics determine how hard it hits you. People with variants in HSD11B2 or COMT may experience substantially amplified effects from the same dose.[6][7][8]
• After reviewing the research, I removed stevia from every Seeking Health product. Optimal Electrolyte, Vitamin C Plus and others were all reformulated. The connection only became obvious because of a customer question I almost dismissed.
• Monk fruit is a clean alternative with no documented diuretic activity, no cortisol elevation, and no endocrine concerns. Watch for erythritol as many monk fruit products are primarily erythritol, which carries its own concerns.[3]
• The fix is simple once you know what to look for. Read every supplement and food label. Stevia, steviol glycosides, stevioside, and rebaudioside A are all derived from the same plant. Any of them on a label means stevia.

You are probably consuming it right now

You drink your morning electrolyte. Thirty minutes later, you need to urinate. Powerful, clean stream. You assume you are well hydrated. Good sign, right?

Maybe.

Or maybe the sweetener in that electrolyte is telling your kidneys to release water and sodium, whether you need to lose it or not.

You take your vitamin C powder mixed into water. Your pre-workout powder before the gym and a protein drink after. A flavored green tea on your desk at work. A protein bar mid-afternoon. Each one sweetened with stevia, marketed as natural, calorie-free, and harmless.

By the end of the day, you have consumed stevia five or six times. You feel vaguely stressed. Your sleep is restless. You urinated more than you expected, given how much you drank. Your cortisol, if you tested it, is likely elevated.

Nobody connected these dots for you. The label says stevia. The marketing says it's natural. You assumed "natural" meant safe, without side effects.

It does not.

How I found out

A while back, a customer emailed our support team with a simple question: "Are there any negatives to using stevia? I heard it can affect hormones."

My first instinct was to say it is natural, it is plant-based. Nothing to worry about. I had been putting stevia in Optimal Electrolyte and several other products for years based on that assumption.

But I stopped myself. I realized I did not actually know for certain. So I went looking.

Turns out the customer was onto something.

What I found surprised me. It immediately connected to something my CEO, Adam, had brought up more than once. He mentioned that every time he used our electrolytes, he had to urinate far more than made sense. At first, I dismissed it. I figured he was just drinking too many glasses a day. Then I started paying attention to myself. After drinking a glass of electrolytes, I noticed the same thing.

I was obsessing over sodium forms, potassium ratios, and magnesium sources. Every active ingredient is carefully chosen for a reason. The whole time, the sweetener I had also carefully selected may have been quietly working against all of it.

Once I understood what stevia was doing, I did not just reformulate the electrolytes. I went through every Seeking Health product with stevia on the label and pulled it. All of them. That was not a small decision. Reformulating means redoing manufacturing flows, rerunning stability testing, and absorbing real costs.

We did it anyway. The research made it clear that keeping stevia in our products would mean knowingly leaving an ingredient that undermines the purpose of the formula.

I listen to our customers. When someone points me toward something I was not aware of, I take it seriously, research it, and if the evidence is there, I act on it.

What stevia actually does in the body

Stevia's sweetness comes from compounds called steviol glycosides. The most common forms you see on labels are stevioside and rebaudioside A, also called Reb A. These are extracted from the leaves of Stevia rebaudiana and are 200 to 300 times sweeter than sugar.

Since the dose is so small, and it is natural, most people assume the effects are negligible. That assumption is worth revisiting.

Steviol glycosides have a steroidal backbone structure. They are chemically similar to steroid hormones like cortisol, testosterone, and estrogen.[4] Structure matters in biology. A compound that looks like a steroid hormone can interact with hormone receptors and enzyme systems in ways a completely unrelated molecule cannot.

Multiple independent lines of research have documented real physiological effects from stevia at doses consistent with normal dietary use. Two of those effects are directly relevant to how you feel every day.

Stevia makes you urinate more

Stevia acts as a diuretic.

A study published in Phytomedicine found that even at doses producing no change in blood pressure or kidney filtration rate, stevia extract significantly increased both water and sodium excretion.[1] The mechanism is specific: stevia inhibits sodium reabsorption in the proximal tubular cells of the kidney. When sodium is not held onto, water follows it out.

This happens regardless of whether you are drinking an electrolyte, a protein shake, or a flavored water. If stevia is in it, the kidneys are getting the signal to release sodium and water.

For someone using an electrolyte drink, this is a direct contradiction. The entire point of sodium in that formula is to help the body retain fluid. The sweetener undermines the active ingredient in real time.

For someone using any other stevia-sweetened product, the effect is the same. It is just less obvious because nobody expects a protein powder to affect kidney function.

Think about your own day. How many stevia-sweetened products did you consume? How many times did you urinate? The connection may not be a coincidence.

If you're looking for an electrolyte that works with your kidneys instead of against them, Optimal Electrolyte provides a comprehensive electrolyte profile with sodium, potassium, magnesium, and chloride, sweetened with monk fruit extract without erythritol.^†

Stevia raises cortisol

There is a second mechanism, and it compounds the first.

A 2017 human clinical study measured cortisol levels in 16 healthy volunteers before and after consuming whole stevia extract for one week.[2] Urinary free cortisol rose from 91.8 to 125.7 nmol per day. The ratio of cortisol to cortisone in urine rose from 1.73 to 2.65. Morning salivary cortisol rose significantly. None of this happened in the placebo group.

That cortisol-to-cortisone ratio is the key number. It points directly at a specific enzyme called 11beta-HSD2, which converts active cortisol into its inactive form in the kidney. When that ratio rises, it means less cortisol is being cleared. The enzyme is being suppressed.

Cortisol is your primary stress hormone. When it rises, ADH gets suppressed. ADH stands for antidiuretic hormone. It is the signal your kidneys receive to retain water.[5] Less ADH means more water is released into the urine.

So stevia drives excess urination through two routes simultaneously.

1. It directly inhibits sodium reabsorption in the renal tubules.
2. It also raises cortisol, which suppresses ADH, which independently increases urinary water loss.

Elevated cortisol means more than just urination

But the cortisol piece goes beyond urination. If you are consuming stevia multiple times per day across multiple products, you are layering cortisol stimulus on top of cortisol stimulus. The result is not acute. It accumulates.

You may feel more irritable than circumstances warrant. Your sleep may be lighter. Your baseline tension is higher. You attribute it to work, to life, to getting older.

You may never think to look at what is sweetening your supplements.

Stevia is in more than you think

Most people associate stevia with health-conscious products and assume it has been thoroughly vetted. I did too. I put it in our products for years without question. It took a customer email to make me look.

The research documenting its cortisol and diuretic effects has not filtered into industry formulation practices. The supplement and food industries adopted stevia as a safe natural sweetener and largely stopped asking questions.

Here is a partial list of product categories where stevia commonly appears:

• Electrolyte powders and drinks
• Protein powders: whey, plant-based, collagen
• Vitamin C and immune support powders
• Greens and superfoods powders
• Pre-workout formulas
• Protein bars and meal replacement bars
• Flavored BCAAs and amino acid supplements
• Kombucha and fermented beverages
• Flavored teas and wellness drinks
• Dairy-free yogurts and protein snacks
• Healthy juices and functional beverages

If you are a health-conscious person taking multiple supplements daily and eating clean packaged foods, you may be consuming stevia five, six, or seven times a day. Each exposure is a small cortisol hit and a diuretic stimulus. Added together across a full day, they are not so small.

This is also why the effect is easy to miss. No single product produces a dramatic response. It is the cumulative load that creates symptoms. And since the sources are distributed across the day in things that are supposed to be healthy, nobody connects them.

Who gets hit hardest: your genetics matter

Not everyone responds to stevia equally. Two genetic factors determine how significantly these effects show up for you.

11beta-HSD2: your cortisol clearance gene

This enzyme converts active cortisol into its inactive form in the kidney. When it functions well, cortisol is cleared efficiently and does not accumulate. When it underperforms, cortisol builds up and acts on the receptors that control sodium and fluid balance.

The 2017 stevia study found that stevia raised the cortisol-to-cortisone ratio significantly, pointing directly at 11beta-HSD2 suppression as the likely mechanism.[2] Variants in this gene are quite common. Research published in Hypertension found that carriers showed a cortisol-to-cortisone ratio 25% higher than non-carriers, meaning substantially less cortisol being cleared.[6] Studies also found marked differences in variant frequency by race, with Black Americans carrying significantly higher rates of 11beta-HSD2 variants than whites. This may partly explain the well-documented higher prevalence of salt-sensitive hypertension in that population.[6]

If you carry one of these variants, stevia is suppressing an enzyme that is already underperforming. Cortisol accumulates further. ADH gets suppressed harder. The result is greater urinary water loss than what most people experience from the same stevia exposure.

COMT Val158Met: your stress response gene

COMT breaks down catecholamines: dopamine, epinephrine, and norepinephrine. The Val158Met variant (rs4680) is one of the most studied polymorphisms in human genetics. It comes in three versions: Val/Val (fast clearance), Val/Met (intermediate), and Met/Met (slow clearance). The Met/Met genotype reduces enzyme activity by three to four times compared to Val/Val.[8]

This matters for stevia because cortisol and catecholamines are tightly linked. Cortisol drives catecholamine release. If stevia raises cortisol, which the 2017 human study showed it does,[2] that cortisol signal lands harder in people who cannot clear the downstream catecholamines efficiently.[9] The result is a more sustained and amplified stress hormone response to the same stevia exposure.

Met/Met is not a rare variant. Roughly one in four people carries it.[8] Val/Met, which also reduces clearance though less severely, accounts for nearly half the population. That means the majority of people have at least some reduction in COMT-driven catecholamine clearance. I call this Slow COMT. The people who notice they feel wired, anxious, or off after consuming stevia-containing products may not be imagining it. Their genetics may be telling them something.

If you have had your genetics analyzed, check your COMT status in your StrateGene report. Understanding which variants you carry helps you understand why your response to stevia may be more pronounced than someone else's.

Why monk fruit is the better choice

When I reformulated, I replaced stevia with monk fruit across all affected products.

Monk fruit sweetener comes from the mogroside compounds in Siraitia grosvenorii, cultivated primarily in southern China. It is 100 to 250 times sweeter than sugar with no calories and no glycemic impact.[10] It has no documented diuretic activity, no evidence of cortisol elevation, and no identified endocrine-disrupting properties. A comprehensive safety review found no reported adverse effects in adults, children, or pregnant women.[11] The FDA has granted it GRAS status and it has been used safely in Asia for centuries.

Monk fruit sweetens without interfering with anything the body is trying to do.

One important caveat: check for erythritol

Many monk fruit products are not pure monk fruit. Erythritol is commonly used as a bulking agent alongside it. It is often the primary ingredient by volume, while monk fruit gets the headline on the front label.

Erythritol is a sugar alcohol that can cause digestive distress at higher doses.[12]

The label should say monk fruit extract or mogroside V. If anything ending in "ol" appears alongside it, you are not getting a pure monk fruit product.

What you can do starting today

• Audit every supplement label you take daily. Look for stevia, steviol glycosides, rebaudioside A, or Reb A. These are all the same compound. If it appears in multiple products, your cumulative daily exposure is likely higher than you realize.
• Check food labels too. Protein bars, flavored teas, kombucha, dairy-free yogurts, healthy juices. Stevia shows up in packaged foods that carry a health halo. The diuretic and cortisol effects are the same regardless of whether it comes from a supplement or a snack.
• Pay attention to your body's response. Frequent urination shortly after consuming a stevia-sweetened product is worth noting. So is a pattern of feeling wired, irritable, or poorly recovered on days when your stevia load is high.
• If you have had your genetics run, check COMT and HSD11B2. Met/Met COMT carriers and people with reduced 11beta-HSD2 activity are likely more sensitive to stevia's cortisol effects. If you are in either group, daily stevia is not a trivial background variable. It is a meaningful stressor. StrateGene checks your COMT status.
• Choose monk fruit without erythritol when selecting sweetened supplements or packaged foods. The label should say monk fruit extract or mogroside V.
• Do not assume natural means inert. Stevia is natural. So is caffeine. So is arsenic. The source of a compound does not determine its pharmacological activity in the body.

The bottom line

I formulate supplements with careful attention to every active ingredient. Every form, every ratio, every source is chosen for a reason. The idea that the sweetener could quietly undermine all of that did not occur to me until a customer asked a question I almost dismissed.

Once I found the research, I did not just fix the electrolytes. I went through the entire Seeking Health range. Stevia is now gone from all of them. It does not matter whether you are drinking an electrolyte or a protein shake. If stevia is in it, it is raising cortisol and telling your kidneys to release sodium and water.

Your genes are not a life sentence. They are a starting point. But they do tell you where you are most vulnerable. If you know your COMT or HSD11B2 status, use that information. And if you do not, start reading your labels.

Frequently asked questions about stevia side effects

Does stevia cause frequent urination?

Yes, research shows stevia inhibits sodium reabsorption in the proximal tubules of the kidney, which causes increased water and sodium loss in urine.[1] This diuretic effect occurs even at typical dietary doses and even when blood pressure and kidney filtration rates remain normal.

Does stevia raise cortisol?

A 2017 human clinical study found that consuming whole stevia extract for one week significantly raised urinary free cortisol, morning salivary cortisol, and the cortisol-to-cortisone ratio in healthy volunteers.[2] The placebo group showed none of these changes. The likely mechanism is suppression of 11beta-HSD2, the enzyme that clears active cortisol in the kidney.

Is monk fruit a safe alternative to stevia?

Monk fruit extract has no documented diuretic activity, no evidence of cortisol elevation, and no identified endocrine-disrupting properties.[10][11] A comprehensive safety review found no adverse effects in adults, children, or pregnant women. Choose products that specify monk fruit extract or mogroside V on the label. Avoid products that also contain erythritol.

Who is most sensitive to stevia's effects?

People with variants in HSD11B2 (the cortisol clearance gene) and COMT Val158Met (the catecholamine clearance gene) are likely more sensitive to stevia's cortisol effects.[6][8] Met/Met COMT carriers have three to four times lower enzyme activity than Val/Val carriers. HSD11B2 variant carriers clear cortisol roughly 25% less efficiently. Both variants are common in the general population.

What other names does stevia go by on labels?

Stevia appears on labels as stevia, steviol glycosides, stevioside, and rebaudioside A (also written as Reb A). All four terms refer to compounds derived from the same plant, Stevia rebaudiana. Any of them on a label means stevia.

Is stevia bad for everyone?

Not necessarily. People with fast COMT clearance (Val/Val) and normal HSD11B2 function may experience less pronounced effects. The concern is cumulative daily exposure across multiple products and the compounding of effects over time, particularly for people with the relevant genetic variants. The question is whether you can tell which group you are in.

Seeking Health supplements to consider

After removing stevia from the full product line, the following Seeking Health products use monk fruit extract without erythritol:^†

Optimal Electrolyte provides a comprehensive electrolyte profile with sodium, potassium, magnesium, chloride, and trace minerals to support hydration without the diuretic or cortisol tradeoffs associated with stevia.†

Vitamin C Plus provides immune system and antioxidant support, reformulated without stevia.†

^† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

References

1. Melis MS. Effect of crude extract of Stevia rebaudiana on renal water and electrolytes excretion. Phytomedicine. 1999;6(4):247-250. https://pubmed.ncbi.nlm.nih.gov/10575620/
2. Al-Dujaili EAS, Twaij H, Bataineh YA, Arshad U, Amjid F. Effect of stevia consumption on blood pressure, stress hormone levels and anthropometrical parameters in healthy persons. Am J Pharmacol Toxicol. 2017;12(1):7-17.
3. Witkowski M, Nemet I, Alamri H, et al. The artificial sweetener erythritol and cardiovascular event risk. Nat Med. 2023;29(3):710-718. PMID: 36849732. https://pubmed.ncbi.nlm.nih.gov/36849732/
4. Bjerregaard AH, Faber J, Kristensen M, et al. In vitro bioassay investigations of the endocrine disrupting potential of steviol glycosides and their metabolite steviol. Mol Cell Endocrinol. 2016;430:25-34. PMID: 27095227. https://pubmed.ncbi.nlm.nih.gov/27095227/
5. Ganong WF. Review of Medical Physiology. 23rd ed. McGraw-Hill; 2009.
6. Agarwal AK, Giacchetti G, Lavery G, et al. CA-repeat polymorphism in intron 1 of HSD11B2: effects on gene expression and salt sensitivity. Hypertension. 2000;36:187-194. PMID: 10948075. https://pubmed.ncbi.nlm.nih.gov/10948075/
7. Williams TA, Mulatero P, Filigheddu F, et al. Role of HSD11B2 polymorphisms in essential hypertension and the diuretic response to thiazides. Kidney Int. 2005;67(2):631-637. PMID: 15673313. https://pubmed.ncbi.nlm.nih.gov/15673313/
8. Jabbi M, Korf J, Kema IP, et al. Convergent genetic modulation of the endocrine stress response involves polymorphic variations of 5-HTT, COMT and MAOA. Mol Psychiatry. 2007;12(5):483-490. PMID: 17179998. https://pubmed.ncbi.nlm.nih.gov/17179998/
9. Oswald LM, Zandi P, Nestadt G, et al. Relationship between cortisol responses to stress and personality. Neuropsychopharmacology. 2006;31(7):1583-1591. PMID: 16395305. https://pubmed.ncbi.nlm.nih.gov/16395305/
10. Pawar RS, Krynitsky AJ, Rader JI. Sweeteners from plants with emphasis on Stevia rebaudiana and Siraitia grosvenorii. Anal Bioanal Chem. 2013;405(13):4397-4407. PMID: 23381804. https://pubmed.ncbi.nlm.nih.gov/23381804/
11. International Food Information Council (IFIC). Everything You Need to Know About Monk Fruit Sweeteners. 2023. Available at: ific.org.
12. Makinen KK. Gastrointestinal disturbances associated with the consumption of sugar alcohols with special consideration of xylitol. Int J Dent. 2016;2016:5765261. PMID: 27840639. https://pubmed.ncbi.nlm.nih.gov/27840639/