Dextrose

Dextrose is the D-form of glucose, a simple monosaccharide with the chemical formula C6H12O6. The term refers to glucose derived from starch and describes the dextro-rotatory isomer that rotates plane-polarised light to the right.

Immediate energy and absorption

Dextrose and glucose are essentially the same molecule. The name dextrose emphasises that the sugar is the D-isomer, which is the only form humans metabolise. Dextrose has a high glycaemic index of 100 and is absorbed rapidly in the small intestine via the sodium–glucose co‑transporter SGLT1. This fast uptake makes it a convenient source of energy for endurance and high-intensity efforts when blood glucose needs to be maintained. However, the rapid digestion also triggers sharp increases in blood sugar and insulin; for sustained exercise, athletes often mix dextrose with slower-releasing carbohydrates such as maltodextrin or fructose to avoid spikes and crashes. Because dextrose is a small molecule, it increases the osmolality of a drink more than longer-chain polymers. To maintain stomach comfort and fluid absorption, formulators usually keep the concentration between about 4 % and 6 %. Dextrose is slightly less sweet than sucrose but provides a clean, sweet taste that encourages fluid intake during prolonged activity.

Practical uses

Mixing 25 g of dextrose into 500 mL of water produces a 5 % carbohydrate solution, which provides quick energy without excessive sweetness. Powdered energy supplements often use dextrose alone or combined with maltodextrin and fructose in ratios such as 2:1 or 1:1 to support multiple transportable carbohydrate uptake. Dextrose is sometimes labelled as corn sugar because it is produced by hydrolysing corn starch; it may also appear on ingredient lists as glucose syrup or corn syrup solids. When using dextrose-based drinks, monitor total carbohydrate intake to stay within the recommended range of 30‑60 g per hour and avoid gastrointestinal distress.

Dextrose delivers fast-acting glucose and is widely used in sports nutrition for immediate energy replenishment. Its high glycaemic index provides quick fuel, but pairing it with other carbohydrates helps sustain energy and maintain hydration during prolonged exercise.

Related Terms: Glucose, Sucrose, Maltodextrin, Fructose, Carbohydrate concentration