GlycerSize (65% Glycerol Powder)

Sports performancehyperhydrationBranded: GlycerSize (Glanbia Nutritionals)Limited dose evidence

Also known as: GlycerSize, glycerol powder 65%, HydroMax, glycerol monostearate replacement, glycerin powder

Add to a formula

GlycerSize is Glanbia Nutritionals' stabilized glycerol powder containing 65% glycerol bound to silica, made to replace older 10–25% glycerol monostearate grades in pre-workouts and hydration products. Glycerol is an osmolyte that, taken with fluid, increases total body water and fluid retention; meta-analyses of glycerol hyperhydration protocols show greater fluid retention and small endurance gains, though those protocols used body-weight-based glycerol doses far above typical supplement servings. In products it is used for muscle fullness and hydration support.

Research summary

Glycerol is absorbed and distributed across body water, raising plasma osmolality so that co-ingested fluid is retained rather than excreted.

Dosage

Daily amounts, of compound.

Lowest studiedTypical rangeHighest studiedUpper limit
2–5 g

2–5 g of GlycerSize powder (1.3–3.25 g glycerol) per serving with at least 500 mL of water, 30–60 minutes before exercise. Research hyperhydration protocols used about 1 g of glycerol per kg body weight with roughly 25 mL/kg of fluid, which is not a practical supplement serving; benefits at typical 2–5 g servings are not established by trials. Because the dose here is the powder, not glycerol, no dose_max_studied is entered.

Standardization: 65% glycerol on silica (GlycerSize)

Source material: vegetable glycerol on silica carrier

Format suitability

  • Capsule
  • Powder
  • Tablet
  • Softgel
  • Gummy
  • Liquid

Very hygroscopic; clumps and cakes in humid conditions and can soften capsules. Use desiccants, low-humidity blending, and moisture-barrier packaging. Best in powders; capsules only with careful moisture control.

Formulation notes

Draws moisture into blends and can destabilize moisture-sensitive ingredients (e.g., probiotics, creatine HCl). Large doses can cause GI discomfort or headache.

Sources

  1. A meta-analysis of the effects of glycerol-induced hyperhydration on fluid retention and endurance performance. (Goulet, 2007)PubMed
  2. Glanbia Nutritionals — GlycerSizeSupplier

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