Reduced concentration oral rehydration solution (or reduced osmolarity oral rehydration solution) is less concentrated than traditionally used in oral rehydration therapy. Some tests have found it to result in "reduced need for unscheduled intravenous infusions, lower stool volume, and less vomiting compared with standard WHO rehydration solution.".[1] In contrast,[2]
However, concerns have been raised that this is unsuitable for universal use, as it may lead to a negative sodium balance in cholera patients, with very serious consequences.[3] For this reason starch-based oral rehydration solutions may be preferred methods of achieving the same effects with less risk,[verification needed] especially in serious cases.
The 2004 WHO recipe for home-made Oral Rehydration Salts:
Add to one litre of safe water:
The standard, manufactured WHO/UNICEF glucose-based ORS solution contains:[verification needed]
| Reduced osmolarity ORS | grams/litre |
|---|---|
| Sodium chloride | 2.6 |
| Anhydrous Glucose | 13.5 |
| Potassium chloride | 1.5 |
| Trisodium citrate, dihydrate | 2.9 |
| Reduced osmolarity ORS | mmol/litre |
|---|---|
| Sodium | 75 |
| Anhydrous Glucose | 75 |
| Chloride | 65 |
| Potassium | 20 |
| Citrate | 10 |
| Total Osmolarity | 245 |
In the human body, the plasma osmolarity is about 285 mOsm/l.
The amount of rehydration that is needed depends on the size of the individual and the degree of dehydration. Rehydration is generally adequate when the person no longer feels thirsty and has a normal urine output. A rough guide to the amount of ORS solution needed in the first 4-6 hours of treatment for a mildly dehydrated person is:
| License | CC-BY-SA-3.0 |
|---|---|
| Cite as | Chriswaterguy (2008–2025). "Reduced concentration oral rehydration solution". Appropedia. Retrieved October 3, 2026. |