The Truth About Protein Powder Sweeteners: A Science-Based Guide

Choosing a protein powder means evaluating more than just protein content. The sweetener used affects taste, digestibility, blood sugar response, and safety during pregnancy and breastfeeding.

This Nutranelle guide helps you understand sweetener options and make informed decisions for your health and your family's wellbeing.

Quick Reference: Sweetener Comparison

Decision Framework: Choosing Based on Your Priorities

If your priority is clean, plant-based ingredients:

Stevia and monk fruit are your only non-synthetic zero-calorie options. Stevia offers better value and availability. Monk fruit provides an alternative if you find stevia's taste unacceptable.

If your priority is maximum safety data during pregnancy and nursing:

Stevia has the most extensive research for use during pregnancy and lactation, with FDA GRAS status and decades of safety studies. Sucralose also has substantial research supporting safety during pregnancy, though many mothers prefer plant-based options.

If your priority is digestive sensitivity:

Stevia produces zero digestive side effects and is the gentlest option. Avoid all sugar alcohols, which can cause bloating, gas, and diarrhea, especially if you're already experiencing pregnancy or postpartum digestive issues.

If you're already experiencing postpartum GI issues:

Choose stevia. It's the most digestively gentle option available. Even if you normally tolerate sugar alcohols well, postpartum digestive sensitivity may make them problematic temporarily.

If your priority is blood sugar management:

Stevia, monk fruit, and artificial sweeteners (sucralose, aspartame, Ace-K) all have zero glycemic impact. Avoid sugar-based sweeteners including coconut sugar, date sugar, and cane sugar. Sugar alcohols have minimal impact but can still affect blood glucose slightly.

If taste is your absolute priority:

Try samples before committing to large containers. Protein powders with high-quality stevia and sucralose typically receive the highest taste ratings in consumer testing.

Taste is highly individual, so what works for others might not work for you.

If you're budget-conscious:

Stevia-sweetened products typically offer the best quality-to-cost ratio among natural sweeteners. Monk fruit commands premium pricing.

Natural Sweeteners: Safety and Performance

Stevia (Steviol Glycosides)

Stevia comes from the leaves of Stevia rebaudiana, a plant native to South America. The FDA granted stevia "Generally Recognized as Safe" (GRAS) status for high-purity steviol glycosides in 2008.

Key facts:

• Zero calories, zero glycemic impact

• FDA GRAS status with extensive pregnancy/lactation safety data

• No digestive side effects

• Typical protein powder serving: 50-100mg steviol glycosides (well below the 272mg daily safe threshold for a 150-pound woman)

Safety considerations:

Research published in Food and Chemical Toxicology found no adverse effects on fertility or fetal development in animal studies even at doses far exceeding human consumption levels.

Stevia does not affect blood glucose or insulin levels, making it safe for women managing gestational diabetes.

Why Some Stevia Tastes Bad and Some Doesn't

The bitter or metallic aftertaste comes from lower-purity extracts or improper formulation. High-purity Rebaudioside A (Reb-A) extracts at 95% purity or higher minimize off-flavors significantly.

Quality formulations pair stevia with natural flavors and ingredients like cocoa powder or vanilla. When properly formulated, most people cannot detect the characteristic stevia aftertaste.

Best for: Mothers prioritizing extensive safety data, clean plant-based ingredients, blood sugar stability, and digestive comfort.

Monk Fruit

Monk fruit extract comes from a small melon grown in Southeast Asia.

The FDA granted it GRAS status in 2010. The sweet compounds are mogrosides, which provide 150-250 times the sweetness of sugar with zero calories.

Key facts:

• Zero calories, zero glycemic impact

• Less long-term pregnancy research compared to stevia, but FDA considers it safe

• Often blended with erythritol (check labels carefully)

• Significantly more expensive due to limited supply

Safety considerations: 

While monk fruit has been used in Traditional Chinese Medicine for centuries, it entered the U.S. market relatively recently. Long-term safety studies during pregnancy are limited compared to stevia, though the FDA considers it safe.

Best for those who find stevia intolerable and are willing to pay a premium for a natural zero-calorie option.

Coconut Sugar, Date Sugar, and Cane Sugar

Some protein powders use coconut sugar, date sugar, or organic cane sugar marketed as "naturally sweetened."

Key facts:

• Coconut sugar: Glycemic index ~54 (table sugar is 65)

• Adds 15-20 calories per serving

• Affects macro tracking and blood sugar similarly to regular sugar

• Mineral content at typical serving sizes is nutritionally insignificant

Safety considerations: 

Women at risk for gestational diabetes should avoid protein powders sweetened primarily with sugar-based sweeteners, regardless of whether they're marketed as "natural."

The American Diabetes Association recommends limiting added sugars during pregnancy.

Best for those prioritizing taste above all other considerations and without blood sugar concerns. Not ideal for pregnant or nursing mothers managing glucose levels.

Related: 5 Best Protein Powders for Gestational Diabetes, Compared

Artificial Sweeteners: The Evidence-Based View

Sucralose (Splenda)

Sucralose is 600 times sweeter than sugar with zero calories. The FDA approved it in 1998 and considers it safe for pregnant and breastfeeding women.

Key facts:

• FDA-approved for pregnancy with decades of research

• Acceptable Daily Intake: 5 mg per kg body weight

• Typical protein powder serving: 40-80mg

• Heat-stable (works in baking and hot beverages)

Studies in 2023-2024 explored sucralose's effects on gut microbiota. Some research suggests high doses may alter beneficial bacteria populations, though these studies typically used doses far exceeding normal consumption.

Clinical significance for occasional protein powder users remains unclear.

Decades of safety research, but many mothers prefer plant-derived options when equally effective plant-based alternatives exist.

Aspartame

Aspartame is 200 times sweeter than sugar. The FDA approved it in 1981.

CRITICAL for pregnancy: People with phenylketonuria (PKU) must avoid aspartame entirely.

All newborns are screened for PKU. If you or your baby has PKU, aspartame is contraindicated.

Key facts:

• Safe for women without PKU at normal consumption levels

• Acceptable Daily Intake: 50 mg per kg body weight

• Degrades in liquid over time (affects pre-mixed shakes)

• Powder forms are more stable

Acesulfame Potassium (Ace-K)

Acesulfame potassium is 200 times sweeter than sugar and often used in combination with other sweeteners.

Key facts:

• FDA-approved since 1988

• Typical protein powder use: 50-100mg per serving (well below safety thresholds)

• Fewer independent long-term studies compared to aspartame and sucralose

Bottom line for artificial sweeteners

All three are FDA-approved and considered safe during pregnancy at normal consumption levels. However, many health-conscious mothers prefer plant-based alternatives when available.

Sugar Alcohols: Understanding the Digestive Trade-Off

Sugar alcohols provide fewer calories than sugar and cause smaller blood glucose spikes, but come with significant digestive considerations.

Critical Tolerance Thresholds

 

Important timing factor: Taking sugar alcohols on an empty stomach increases likelihood of digestive issues. Consuming them with food may improve tolerance.

Erythritol

Your small intestine absorbs about 90% of consumed erythritol, then excretes it unchanged in urine. This explains why it causes fewer digestive issues than other sugar alcohols.

The cooling effect: Erythritol creates a cooling sensation on the tongue (similar to mint). Some find this pleasant; others find it distracting in protein shakes.

A study in Nature Medicine suggested a potential link between high blood erythritol levels and cardiovascular events.

However, the study showed correlation, not causation, and most blood erythritol comes from metabolism, not diet. The FDA has not changed its GRAS status. Pregnant women seeking to minimize any potential risk may prefer other options.

Xylitol

Xylitol offers genuine dental benefits by reducing cavity-causing bacteria, which may interest mothers concerned about oral health during pregnancy.

CRITICAL PET SAFETY WARNING: Xylitol is extremely toxic to dogs, causing rapid insulin release and potentially fatal hypoglycemia. If you have dogs, store xylitol-containing products securely and clean up spills immediately.

Allulose

Technically a "rare sugar" rather than a sugar alcohol. Your body absorbs but does not metabolize allulose, so it provides minimal calories and does not affect blood sugar.

Better digestive tolerance than most sugar alcohols.

Key Insight for Mothers

Pregnancy hormones slow digestive transit. Many women struggle with constipation and bloating even without sugar alcohols. If you're already experiencing digestive sensitivity during or after pregnancy, sugar alcohols will likely make it worse.

Pregnancy and Breastfeeding: Key Considerations

 

Transfer to breast milk

Most sweeteners do not pass into breast milk in significant quantities. Stevia and monk fruit have no evidence of transfer. Artificial sweeteners pass in trace amounts considered safe by medical authorities.

Note: Postpartum depression and anxiety affect up to 1 in 8 women. While sweetener choice won't prevent these conditions, maintaining steady energy through stable blood sugar can support overall mental health.

Unsweetened and Lightly Sweetened Options

Unsweetened Protein Powders

Unsweetened options give you complete control. Add fresh fruit, honey, maple syrup, or dates to smoothies, adjusting to your preference.

Benefits:

• Complete customization

• Often cost less

• No sweetener concerns

Reality check: Unsweetened protein powder tastes chalky and slightly bitter. If you're adding it to a fruit smoothie, this isn't an issue. If you're mixing it with water or unsweetened almond milk, you probably won't enjoy it.

Lightly Sweetened Options

Some brands offer "lightly sweetened" versions with reduced sweetener quantities. These maintain basic palatability while allowing room to add fruit without over-sweetening.

Best for: People who primarily use protein in smoothies where fruit provides additional sweetness, or those who prefer subtle flavors.

Making Your Choice

Sweetener selection in protein powder matters, particularly for pregnant and nursing mothers. The right choice supports your health goals without compromising safety, digestive comfort, or blood sugar stability.

Nutranelle uses high-purity stevia leaf extract (steviol glycosides) in both our whey protein powder and plant-based protein powder because it aligns with what matters most to mothers.

Why stevia:

• Extensive safety data for pregnancy and breastfeeding (FDA GRAS status, decades of research)

• Plant-derived with no synthetic additives

• Zero digestive side effects (we specifically avoid sugar alcohols)

• Zero blood sugar impact (safe for gestational diabetes management)

• High-purity steviol glycosides balanced with natural ingredients (cocoa powder in chocolate, natural vanilla in plant-based) to minimize aftertaste

Both our plant and whey protein options include comprehensive digestive enzyme blends with protease, amylase, lactase, and lipase. These support optimal protein absorption and digestive comfort.

Whether you choose our whey or plant-based protein, you're getting protein powder formulated specifically for women who refuse to compromise on ingredient quality, especially during pregnancy and motherhood.