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The science behind the formula

Pure Hydration IV

A summary of the published, peer-reviewed research on the ingredients in this formula. Every claim below is linked to its source study.

  • 10 peer-reviewed sources
  • Every citation verified

What’s in it

Lactated Ringer's solution, 250 mL, 500 mL or 1,000 mL. No additives.

What the research shows

Hydration status has larger and faster effects on how people feel and perform than is generally appreciated, and the evidence is from controlled human trials rather than inference. A randomized crossover clinical study found that even mild dehydration — barely over 1% of body weight — was enough to dull concentration and drive up fatigue 1. A randomized controlled trial found that rehydrating a dehydrated person measurably improves mental processing speed, working memory, mood and fatigue 2. A meta-analysis established that real physical output depends on fluid status too: muscle endurance, strength and anaerobic power all measurably track hydration 3. And in people with recurrent headaches, a randomized controlled trial found increasing fluid intake significantly improved headache-related quality of life, with nearly half of participants reporting meaningful relief 4.

The advantage of the intravenous route is one of speed and completeness. A randomized crossover clinical trial directly compared the two and found that when people are dehydrated, an IV restores blood volume faster than drinking the same amount of fluid 5. This matters most when someone is already behind — after illness, travel, heat exposure or hard training — where the gut is the bottleneck rather than the fluid supply.

Our choice of fluid is deliberate. We use Lactated Ringer's, a balanced crystalloid built to match the body's own blood chemistry, whose lactate is converted by the liver into bicarbonate, the body's natural buffer 6. This is not a cosmetic distinction. In the largest randomized comparison ever run, balanced crystalloids such as Lactated Ringer's protected the kidneys better than plain saline 7, and the same advantage appeared in ordinary, non-critically-ill patients receiving routine IV fluids 8. A systematic review pooling every major trial patient-by-patient found balanced crystalloids came out ahead of saline on survival 9, and a prospective sequential-period study found choosing lower-chloride fluids over saline was associated with roughly half the rate of kidney injury 10.

Full ingredient list

Exact amounts delivered in each size. Formulas are compounded per patient and can be adjusted by your provider.

Small · 250 mL

Lactated Ringer's Solution 250 mL

Medium · 500 mL

Lactated Ringer's Solution 500 mL

Large · 1000 mL

Lactated Ringer's Solution 1000 mL

Supporting studies

  • 1

    Even mild dehydration — barely over 1% of body weight — is enough to dull concentration and drive up fatigue, which is why hydration status matters for how you feel day to day.

    In this controlled crossover study of 26 healthy young men, mild dehydration of about 1.6% body mass produced significant adverse changes in vigilance and working memory, increased tension/anxiety and fatigue, and raised ratings of task difficulty and concentration effort. The authors concluded that degraded mood, increased perception of task difficulty, lower concentration and headache symptoms result from mild dehydration in healthy young men — establishing how small a fluid deficit it takes to affect performance.

    Randomized crossover clinical study Ganio MS, et al. Mild dehydration impairs cognitive performance and mood of men. British Journal of Nutrition. 2011. PMID 21736786 ↗

  • 2

    Rehydrating a dehydrated person measurably improves mental processing speed, working memory, mood and fatigue.

    This randomized controlled trial in young adults first induced mild dehydration through 36 hours of water restriction, then randomized participants to different rehydration volumes. Rehydration improved processing speed, working memory and mood, with 1,000 mL identified as the optimum volume; the two largest rehydration doses significantly improved fatigue scores, total mood disturbance and cognitive test performance. This is direct evidence that restoring fluid — not merely avoiding dehydration — makes people think and feel better. (Route: oral rehydration.)

    Randomized controlled trial Zhang J, et al. Effects of Water Restriction and Supplementation on Cognitive Performances and Mood among Young Adults in Baoding, China: A Randomized Controlled Trial (RCT). Nutrients. 2021. PMID 34684650 ↗

  • 3

    Staying properly hydrated protects real physical output — muscle endurance, strength and anaerobic power all measurably depend on fluid status.

    This meta-analysis pooled 28 published studies measuring muscular performance in hydrated versus dehydrated states. Hypohydration was associated with reductions of 8.3% in muscle endurance, 5.5% in muscle strength, and 5.8% in anaerobic power. The scale of these decrements shows that correcting a fluid deficit is directly relevant to how strong and capable a person feels and performs.

    Meta-analysis Savoie FA, et al. Effect of Hypohydration on Muscle Endurance, Strength, Anaerobic Power and Capacity and Vertical Jumping Ability: A Meta-Analysis. Sports Medicine. 2015. PMID 26178327 ↗

  • 4

    In people with recurrent headaches, increasing fluid intake significantly improved headache-related quality of life, and nearly half reported meaningful relief.

    This randomized controlled trial in primary care enrolled patients with recurrent moderate-to-severe headaches who were drinking under 2.5 L of fluid per day, and randomized them to add 1.5 L of water daily or to control. Over three months the water group gained a statistically significant 4.5-point improvement on the Migraine-Specific Quality of Life scale, and 47% of the water group reported substantial improvement (6 or higher on a 10-point scale) versus 25% of controls. (Route: oral fluid.)

    Randomized controlled trial Spigt M, et al. A randomized trial on the effects of regular water intake in patients with recurrent headaches. Family Practice. 2012. PMID 22113647 ↗

  • 5

    When people are dehydrated, an IV restores blood volume faster than drinking the same amount of fluid.

    In this randomized crossover study, participants were dehydrated by exercise and then rehydrated either intravenously, orally, or not at all before a subsequent heat-stress exercise test. Plasma volume after rehydration was significantly greater in the IV condition than in the oral or no-fluid conditions (P<0.05), confirming that the intravenous route restores circulating blood volume more rapidly and completely than swallowing fluid, which must first be absorbed through the gut.

    Randomized crossover clinical trial (human physiology) Kenefick RW, et al. Rapid IV versus oral rehydration: responses to subsequent exercise heat stress. Medicine & Science in Sports & Exercise. 2006. PMID 17146319 ↗

  • 6

    Lactated Ringer's is built to match your own blood chemistry, and its lactate is converted into bicarbonate — the body's natural buffer.

    This clinical review in the American Journal of Respiratory and Critical Care Medicine explains that balanced crystalloids such as lactated Ringer's carry sodium, potassium and chloride concentrations closer to those of human extracellular fluid than saline does, and therefore have fewer adverse effects on acid-base balance when infused. The review documents that operating-room trials showed balanced crystalloids rather than saline prevent the development of hyperchloremic metabolic acidosis, and notes emerging evidence that the lactate itself serves as a fuel for the brain and heart under stress.

    Concise clinical review (physiology and trial evidence) Semler MW, Kellum JA Balanced Crystalloid Solutions. American Journal of Respiratory and Critical Care Medicine. 2019. PMID 30407838 ↗

  • 7

    In the largest randomized comparison ever run, balanced crystalloids such as Lactated Ringer's protected the kidneys better than plain saline.

    The SMART trial randomized 15,802 adults to receive either a balanced crystalloid (lactated Ringer's or Plasma-Lyte A) or 0.9% saline as their IV fluid. The composite outcome of death, new dialysis, or persistent kidney dysfunction at 30 days occurred in 14.3% of the balanced-crystalloid group versus 15.4% of the saline group (odds ratio 0.90; 95% CI 0.82–0.99; P=0.04). The authors concluded that using balanced crystalloids rather than saline for intravenous fluid administration produced a lower rate of adverse kidney events.

    Randomized controlled trial (pragmatic, cluster-randomized, multiple-crossover) Semler MW, et al. (SMART Investigators) Balanced Crystalloids versus Saline in Critically Ill Adults. New England Journal of Medicine. 2018. PMID 29485925 ↗

  • 8

    The same kidney advantage for balanced fluids showed up in ordinary, non-critically-ill patients receiving routine IV fluids.

    The SALT-ED trial randomized 13,347 adults who received IV crystalloids (median volume about 1,079 mL) to balanced crystalloids or saline. Major adverse kidney events within 30 days occurred in 4.7% of the balanced-crystalloid group versus 5.6% of the saline group (adjusted odds ratio 0.82; 95% CI 0.70–0.95; P=0.01). This is the closest large trial to an outpatient-style setting, using modest fluid volumes rather than intensive-care resuscitation.

    Randomized controlled trial (pragmatic, multiple-crossover) Self WH, et al. (SALT-ED Investigators) Balanced Crystalloids versus Saline in Noncritically Ill Adults. New England Journal of Medicine. 2018. PMID 29485926 ↗

  • 9

    Pooling every major trial patient-by-patient, balanced crystalloids came out ahead of saline on survival.

    The BEST-Living project combined individual patient data from 6 randomized trials totaling 34,685 patients comparing balanced solutions with saline. In-hospital mortality was 16.8% with balanced solutions versus 17.3% with saline (odds ratio 0.962). Using a Bayesian analysis, the authors calculated an 89.5% posterior probability that balanced solutions reduce in-hospital mortality, concluding that the probability of benefit is high.

    Systematic review and individual patient data meta-analysis Zampieri FG, et al. Balanced crystalloids versus saline for critically ill patients (BEST-Living): a systematic review and individual patient data meta-analysis. The Lancet Respiratory Medicine. 2024. PMID 38043564 ↗

  • 10

    Choosing lower-chloride IV fluids over saline was linked to roughly half the rate of kidney injury.

    In this before-and-after study of 1,533 intensive care patients in Melbourne, a chloride-restrictive IV fluid strategy (favoring lactated/Hartmann's solution and balanced fluids over chloride-rich saline) was compared with the previous chloride-liberal practice. Injury- or failure-class acute kidney injury fell from 14% to 8.4% (adjusted odds ratio 0.52; 95% CI 0.37–0.75; P<0.001) and the need for renal replacement therapy fell from 10% to 6.3% (adjusted odds ratio 0.52; 95% CI 0.33–0.81; P=0.004). This is the clinical evidence behind the physiologic argument for lower-chloride, balanced fluids.

    Prospective open-label sequential-period clinical study Yunos NM, et al. Association between a chloride-liberal vs chloride-restrictive intravenous fluid administration strategy and kidney injury in critically ill adults. JAMA. 2012. PMID 23073953 ↗

References

  • 1Ganio MS, et al. Mild dehydration impairs cognitive performance and mood of men. British Journal of Nutrition. 2011. PMID 21736786 ↗
  • 2Zhang J, et al. Effects of Water Restriction and Supplementation on Cognitive Performances and Mood among Young Adults in Baoding, China: A Randomized Controlled Trial (RCT). Nutrients. 2021. PMID 34684650 ↗
  • 3Savoie FA, et al. Effect of Hypohydration on Muscle Endurance, Strength, Anaerobic Power and Capacity and Vertical Jumping Ability: A Meta-Analysis. Sports Medicine. 2015. PMID 26178327 ↗
  • 4Spigt M, et al. A randomized trial on the effects of regular water intake in patients with recurrent headaches. Family Practice. 2012. PMID 22113647 ↗
  • 5Kenefick RW, et al. Rapid IV versus oral rehydration: responses to subsequent exercise heat stress. Medicine & Science in Sports & Exercise. 2006. PMID 17146319 ↗
  • 6Semler MW, Kellum JA. Balanced Crystalloid Solutions. American Journal of Respiratory and Critical Care Medicine. 2019. PMID 30407838 ↗
  • 7Semler MW, et al. (SMART Investigators). Balanced Crystalloids versus Saline in Critically Ill Adults. New England Journal of Medicine. 2018. PMID 29485925 ↗
  • 8Self WH, et al. (SALT-ED Investigators). Balanced Crystalloids versus Saline in Noncritically Ill Adults. New England Journal of Medicine. 2018. PMID 29485926 ↗
  • 9Zampieri FG, et al. Balanced crystalloids versus saline for critically ill patients (BEST-Living): a systematic review and individual patient data meta-analysis. The Lancet Respiratory Medicine. 2024. PMID 38043564 ↗
  • 10Yunos NM, et al. Association between a chloride-liberal vs chloride-restrictive intravenous fluid administration strategy and kidney injury in critically ill adults. JAMA. 2012. PMID 23073953 ↗

On our sourcing. Every one of the 10 sources on this page was checked against the live PubMed database — confirming that each PubMed ID points to the exact paper cited, with a matching title, journal and year. Click any reference to read the original.

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This page describes what the published research shows about the ingredients in this formula. It is educational information about those ingredients. It is not a claim that this or any Nature & Science Medicine infusion diagnoses, treats, cures or prevents any disease, and it is not a substitute for a consultation with a licensed provider. Individual results vary.