Our Verdict
Nuun Sport offers the most affordable per-serving price in this batch ($0.75) with an Informed Choice certification that most competitors lack. However, the use of Magnesium Oxide -- which has only 4-15% bioavailability compared to 25-30% for citrate or malate forms -- undermines the already-low 25mg magnesium dose. The PFAS/organic fluorine detection (Mamavation, Dec 2023) is concerning though not conclusive.
Evident Ratings
Nuun Nuun Sport Electrolyte Tablets
Scored across 5 dimensions on a 5-point scale
About Nuun
Founded in 2004, Nuun pioneered the effervescent electrolyte tablet format. One of the oldest brands in the category with strong endurance sports credibility. Based in Seattle, WA.
Product specifications
- Form
- tablet
- Serving Size
- 1 tablet (5g)
- Calories
- 15
- Sugar
- 1g
- Made In
- USA
How we scored this
Every data point below is tagged as Verified (independently confirmed) or Claimed (brand-stated).
Material Safety
- No Artificial Sweeteners
- Yes — Sweetened with stevia onlyVerified
- No Artificial Flavors
- YesVerified
- No Artificial Colors
- Yes — Uses beet juice, riboflavin, spirulina for colorVerified
- No Natural Flavors
- No — Contains 'Natural Flavors'Verified
- No Fillers
- No — Contains avocado oil, rice extract blendVerified
- Transparent Label
- Yes — All electrolyte amounts individually listedVerified
- No Proprietary Blends
- YesVerified
- Clean Mineral Sources
- No — Uses Magnesium Oxide (4-15% bioavailability) and Calcium Carbonate (cheaper form)Verified
- Sweetener
- Stevia Leaf ExtractVerified
- Full Ingredients
- Citric Acid, Dextrose, Sodium Bicarbonate, Potassium Bicarbonate, Sodium Carbonate, Natural Flavor, Potassium Chloride, Magnesium Oxide, Calcium Carbonate, Stevia Leaf Extract, Avocado Oil, Rice Extract Blend, Beet Juice Powder (color)Verified
Testing & Trust
- Third-Party Tested
- Yes — Nuun Sport is Informed Choice certified (monthly batch testing)Verified
- COA Available
- Unknown
- Heavy Metals Tested
- Unknown
- Certifications
- non gmo, vegan, gluten freeVerified
Value & Policy
- Price Per Serving
- $0.75Verified
- Package Price
- $7.49 (10 servings)Verified
- Return Policy
- 30-day satisfaction guaranteeClaimed
- Subscription Discount
- 20%Claimed
- Sample Packs
- AvailableVerified
Product Features
- Sodium
- 300mgVerified
- Potassium
- 150mgVerified
- Magnesium
- 25mgVerified
- Calcium
- 13mgVerified
- Chloride
- 40mgVerified
- Sodium Source
- Sodium Bicarbonate, Sodium CarbonateVerified
- Magnesium Source
- Magnesium Oxide (poorest bioavailability, 4-15% absorption)Verified
- Amazon Rating
- 4.6 stars (45,000 reviews)Verified
- Red Flags
- Magnesium Oxide (cheapest, least bioavailable form at 4-15% absorption); PFAS/organic fluorine detected in Mamavation testing (Dec 2023) -- trace amounts of organic fluorine found, though this could indicate fluorinated pesticides rather than intentional PFAS use; Very low magnesium (25mg) and calcium (13mg) amounts despite listing them as key electrolytesVerified
See how Nuun stacks up against every electrolytes we tested
Our full electrolytes comparison ranks every brand across the same scoring dimensions you saw above — formulation, testing, trust, value, and sourcing.
See Best Electrolytes →Other top electrolytes we tested
Get our latest research
New reviews and sleep science insights — no spam, ever.