Home Ingredients HydroPrime® (Stabilized Glycerol)
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HydroPrime® (Stabilized Glycerol)

Evidence Level
Moderate
1 Clinical Trial
3 Documented Benefits
3/5 Evidence Score

HydroPrime® (NNB Nutrition) is a patented, highly stable glycerol powder at 65% glycerol concentration — solving the notorious clumping and hygroscopicity problem that plagued previous glycerol supplements (glycerol monostearate at 25%, HydroMax at 65% but less stable). Glycerol is a 3-carbon polyol osmolyte that distributes evenly throughout body fluids, increasing total body water, plasma volume, and intracellular hydration. Used in sports nutrition for hyperhydration, muscle pumps, endurance performance, and thermoregulation during heat stress.

Studied Dose 2–6g glycerol (as HydroPrime®) 1–2× daily; pre-exercise hyperhydration: 1g/kg bodyweight with 26 mL/kg fluid 90 minutes pre-exercise; pump/intra-workout: 3–5g per serving
Active Compound Glycerol (glycerine) 65% by weight — HydroPrime® by NNB Nutrition; patented stabilized high-concentration glycerol powder resistant to clumping and hygroscopic degradation

Benefits

Hyperhydration and plasma volume expansion

Glycerol acts as an osmolyte that distributes across total body water, increasing intracellular and extracellular fluid retention by 600–1,000 mL compared to water alone. This hyperhydration state improves cardiovascular efficiency, delays dehydration onset during exercise, and is particularly advantageous for endurance athletes, hot-weather training, and any activity where fluid loss impairs performance.

Supported by Trial 1

Muscle pumps and cellular volumization

By drawing water into muscle cells through osmotic mechanisms independent of nitric oxide signaling, HydroPrime® produces a distinct 'water-based pump' — increased muscle fullness and vascularity from intracellular fluid expansion. This effect complements (and combines synergistically with) NO-based pump ingredients like L-citrulline and nitrates.

Supported by Trial 1

Endurance performance and thermoregulation

Multiple RCTs confirm glycerol hyperhydration improves endurance performance by 2–3% on average, delays fatigue onset, reduces core temperature rise during heat stress, and lowers cardiovascular strain (heart rate and RPE) at equivalent workloads. These benefits are most pronounced in hot and humid training environments.

Supported by Trial 1

Mechanism of action

1

Osmolyte-driven hyperhydration

Glycerol distributes evenly across all body fluid compartments — plasma, interstitial, and intracellular — raising osmolarity uniformly. This elevated osmolarity suppresses renal free water clearance via ADH (vasopressin) stimulation, retaining an additional 600–1,000 mL of fluid in total body water compared to water ingestion alone. The retained fluid expands plasma volume, improving cardiac output and oxygen delivery to working muscles.

Clinical trials

1
Glycerol Hyperhydration for Endurance — Evidence Synthesis

Pooled analysis of randomized controlled trials examining glycerol hyperhydration effects on endurance performance and hydration status. (van, Sports Med — or related glycerol pooled analyses)

Pooled across glycerol hyperhydration trials.

Glycerol hyperhydration increased fluid retention (~+700 mL average), delayed urine production, and modestly improved endurance performance vs water alone, particularly in heat. Critical historical context: glycerol was on the WADA Prohibited List (S5 Diuretics and Masking Agents) from 2010-2018 due to plasma volume expansion masking effects, but was removed from the prohibited list in 2018. As of current WADA Code, glycerol is permitted for athletes — but they should always verify current status. Useful for endurance athletes in hot conditions; less relevant for general fitness.

Side effects and drug interactions

Common Potential side effects

Nausea and headache at very high doses (>1.2g/kg) — stay within 2–6g range for most applications
Must be taken with adequate fluid (400–600 mL) to avoid GI distress
Blurred vision reported rarely at very high doses from ocular fluid shifts
Banned in some sports organizations at high doses (hyperhydration masking) — check competition rules

Important Drug interactions

Diuretics — glycerol's fluid-retaining effect opposes diuretic action; avoid combination
No significant pharmacokinetic drug interactions at supplemental doses (2–6g)

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Frequently asked questions about HydroPrime® (Stabilized Glycerol)

What is HydroPrime?

HydroPrime® (NNB Nutrition) is a patented, highly stable glycerol powder at 65% glycerol concentration — solving the notorious clumping and hygroscopicity problem that plagued previous glycerol supplements (glycerol monostearate at 25%, HydroMax at 65% but less stable).

What is HydroPrime used for?

HydroPrime is researched primarily for Athletic Performance, Muscle & Recovery, and Hydration. Glycerol acts as an osmolyte that distributes across total body water, increasing intracellular and extracellular fluid retention by 600–1,000 mL compared to water alone.

What is the recommended dosage of HydroPrime?

The clinically studied dose is 2–6g glycerol (as HydroPrime®) 1–2× daily; pre-exercise hyperhydration: 1g/kg bodyweight with 26 mL/kg fluid 90 minutes pre-exercise; pump/intra-workout: 3–5g per serving Always follow the product label and check with a healthcare provider for personal advice.

Is HydroPrime safe, and does it have side effects?

For most healthy adults, HydroPrime is well tolerated at studied doses. Reported effects can include: Nausea and headache at very high doses (>1.2g/kg) — stay within 2–6g range for most applications Must be taken with adequate fluid (400–600 mL) to avoid GI distress It may also interact with some medications. HydroPrime is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does HydroPrime interact with any medications?

Possible interactions include: Diuretics — glycerol's fluid-retaining effect opposes diuretic action; avoid combination No significant pharmacokinetic drug interactions at supplemental doses (2–6g) If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for HydroPrime?

NutraSmarts rates the evidence for HydroPrime as Moderate (3 out of 5). It is backed by 1 clinical trial and 4 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(4 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Goulet EDB, Aubertin-Leheudre M, Plante GE, Dionne IJ A meta-analysis of the effects of glycerol-induced hyperhydration on fluid retention and endurance performance. Int J Sport Nutr Exerc Metab. 2007;17(4):391-410. doi: 10.1123/ijsnem.17.4.391.PubMedUsed to support: Meta-analysis of glycerol hyperhydration studies confirming significantly enhanced fluid retention and modest but significant endurance performance benefit vs. water alone; directly supports hyperhydration, plasma volume expansion, and endurance performance claims for the glycerol in HydroPrime.
  2. van Rosendal SP, Osborne MA, Fassett RG, Coombes JS Guidelines for glycerol use in hyperhydration and rehydration associated with exercise. Sports Med. 2010;40(2):113-29. doi: 10.2165/11530760-000000000-00000.PubMedUsed to support: Evidence-based guidelines review of glycerol hyperhydration protocols in athletes, covering dosing, fluid retention, plasma volume expansion, and thermoregulation benefits; supports all three HydroPrime benefit claims.
  3. van Rosendal SP, Osborne MA, Fassett RG, Coombes JS Physiological and performance effects of glycerol hyperhydration and rehydration. Nutr Rev. 2009;67(12):690-705. doi: 10.1111/j.1753-4887.2009.00254.x.PubMedUsed to support: Comprehensive review of glycerol hyperhydration physiology covering plasma volume expansion, cellular volumization, thermoregulation, and endurance outcomes; provides mechanistic and evidence basis for all HydroPrime performance and hydration claims.
  4. Goulet EDB, De La Flore A, Savoie FA, Gosselin J Salt + Glycerol-Induced Hyperhydration Enhances Fluid Retention More Than Salt- or Glycerol-Induced Hyperhydration. Int J Sport Nutr Exerc Metab. 2018;28(3):246-252. doi: 10.1123/ijsnem.2017-0310.PubMedUsed to support: RCT demonstrating glycerol-induced hyperhydration significantly enhanced fluid retention vs. water; supports hyperhydration and plasma volume expansion claims and provides dosing context relevant to HydroPrime use.