Maltodextrin vs cyclic dextrin vs glucose: does it matter?
Cyclic dextrin sells at 4× the price on a claim about gastric emptying. We pulled the trials side by side — here's what actually moves the needle and what's marketing.
Highly-branched cyclic dextrin (HBCD, often sold as Cluster Dextrin®) is the premium-tier carb of the moment. The pitch: lower osmolality, faster gastric emptying, smoother ride for the gut. The price: roughly four times maltodextrin per gram.
What the trials actually show
There are a handful of small studies (typically n=8–12) comparing HBCD against maltodextrin or glucose during exercise. The signal is real but modest: slightly lower RPE in a few protocols, faster gastric emptying in others, and mixed findings on time-trial performance — a couple of small trials show a modest benefit, others show none.
What moves the needle more
- Total carbs per hour (60 → 90 → 120 g/h). This is the biggest lever, by an order of magnitude.
- Glucose:fructose ratio. ~1:0.8 lets you push past the SGLT1 ceiling. This is well-replicated.
- Concentration in the bottle. ~6–8% empties faster than 12%. Free, no premium ingredient required.
- Sodium. ~500–700 mg/L for long efforts in heat. Cheap, ignored, makes the bigger difference.
We use maltodextrin because the marginal benefit of HBCD doesn't justify a 4× ingredient cost we'd have to pass to you. If a future trial changes that, we'll change the recipe — and tell you why on this page.
- Furuyashiki T et al. Effects of ingesting highly branched cyclic dextrin during endurance exercise on rating of perceived exertion and blood components associated with energy metabolism. Biosci Biotechnol Biochem. 2014;78(12):2117–9.
- Wilburn D, Machek S, Ismaeel A. Highly Branched Cyclic Dextrin and its Ergogenic Effects in Athletes: A Brief Review. J Exerc Nutr. 2021;4(3).
- Jeukendrup AE. Carbohydrate intake during exercise and performance. Nutrition. 2004.