How to Constitute Oral Rehydration Solution Correctly

November 16, 2025 •

3 min read

According to the World Health Organization, oral rehydration solution (ORS) has saved millions of lives by effectively treating dehydration from diarrhea. Knowing how to constitute oral rehydration solution correctly is a critical skill, as improper preparation can worsen health conditions.

Quick Summary

A step-by-step guide to mixing commercial ORS packets and a homemade version. This involves using the correct amount of clean water, following precise measurements for ingredients like salt and sugar, and adhering to safety guidelines. Covers the scientific basis and proper administration techniques.

Key Points

Cleanliness is Critical: Wash hands and use clean equipment before preparing ORS to prevent bacterial contamination.
Accurate Measurement is Key: Precise quantities of water, salt, and sugar are vital, as improper ratios can lead to dangerous electrolyte imbalances.
Use Commercial ORS if Possible: Pre-packaged ORS packets are the most reliable and safest option due to their scientifically balanced composition.
Homemade ORS is an Emergency Option: Only use homemade oral rehydration solutions when commercial packets are unavailable, and follow the WHO formula strictly.
Never Use Unsafe Water: Always use clean, safe water, preferably boiled and cooled, to prevent infection.
Discard After 24 Hours: Any unused ORS solution should be covered and discarded after 24 hours to ensure safety.
Give Small, Frequent Sips: Administer the solution slowly, especially after vomiting, to maximize absorption and minimize stomach upset.

Why Proper ORS Preparation is Crucial

Oral rehydration solution (ORS) is a specific mixture of salts and sugars that helps the body absorb water more effectively during dehydration. Unlike plain water, which can dilute the body's electrolytes further, ORS works by utilizing the sodium-glucose co-transport system in the intestines to maximize fluid absorption. Incorrectly preparing ORS—either with too much or too little water or with improper ingredient ratios—can be dangerous. An overly concentrated solution can lead to salt toxicity (hypernatremia), while one that is too diluted may be ineffective. The key is precision to ensure the body restores lost fluids and electrolytes, such as sodium and potassium, in the correct balance.

Method 1: How to Constitute Oral Rehydration Solution from a Commercial Packet

Using a commercial ORS packet is the most reliable method, as it contains a pre-measured, scientifically formulated blend of ingredients. Always follow the manufacturer's instructions precisely.

Step-by-Step Guide for Packet ORS

Hand and Equipment Hygiene: Before you begin, wash your hands thoroughly with soap and clean water. Gather a clean container, such as a jug or pitcher, and a clean utensil for mixing.
Measure the Water: The most important step is adding the exact amount of clean, safe water. The packet will specify the volume, typically one liter. Use water that has been boiled and cooled, bottled, or disinfected. Do not use more or less than the recommended amount.
Mix the Powder: Carefully cut open the ORS packet and pour the entire contents into the container of water. Stir the mixture until the powder is completely dissolved.
Administer the Solution: Give the solution to the patient in small, frequent sips from a clean cup or spoon. This is especially important for young children. If the patient vomits, wait 5 to 10 minutes before resuming at a slower pace.
Storage: Any unused solution must be covered and discarded after 24 hours to prevent bacterial contamination.

Method 2: How to Constitute Oral Rehydration Solution at Home (WHO Formula)

While commercial packets are safer, a homemade solution can be used in emergencies when packets are unavailable. This is a temporary measure until professional medical help or a proper ORS packet can be obtained. Be extremely cautious with measurements, as mistakes can be harmful.

Ingredients for Homemade ORS

1 liter of clean, safe water (boiled and cooled is ideal)
6 level teaspoons of sugar
1/2 level teaspoon of salt

Step-by-Step Guide for Homemade ORS

Prepare the Water: Use a clean container and add one liter of clean, cool water. Measure the water accurately.
Measure and Add Ingredients: Using level measurements, add six teaspoons of sugar and half a teaspoon of salt to the water.
Mix Thoroughly: Stir the mixture until both the sugar and salt have completely dissolved. Taste the solution; it should not taste sweeter than a soft drink or saltier than tears.
Administer Carefully: Give the solution in small, frequent sips. Discard any unused solution after 24 hours.

Comparison: Commercial vs. Homemade ORS


Feature	Commercial ORS Packet	Homemade ORS
Accuracy	Pre-measured, scientifically balanced ingredients ensure optimal electrolyte levels and absorption.	Dependent on accurate household measurements, which can be prone to error.
Safety	High safety profile; recommended by WHO and UNICEF for reliability. Incorrect dilution is the main risk.	Higher risk of causing electrolyte imbalance if mixed improperly. Only recommended as a temporary emergency measure.
Ease of Use	Simple and quick; just requires mixing with the specified volume of water.	Requires careful, level measurements of sugar and salt, which can be tricky.
Composition	Standardized low-osmolarity formula to reduce stool volume and duration of diarrhea.	Basic formula designed to provide a necessary balance of sodium and glucose.
Availability	Available at most pharmacies and health centers globally.	Can be prepared immediately with common household items if packets are unavailable.

Conclusion: Prioritizing Safety and Accuracy

Whether using a commercial packet or preparing a homemade version in an emergency, knowing how to constitute oral rehydration solution correctly is a life-saving skill. The process is straightforward but demands accuracy to prevent potentially dangerous side effects from imbalances. Always prioritize using a commercial, pre-packaged ORS if available, as it guarantees a precise and effective formulation. For those situations where an emergency homemade solution is necessary, follow the World Health Organization's formula exactly and use it only as a stop-gap measure while seeking a commercial alternative or professional medical advice. By adhering to these guidelines, you can ensure that the solution provides maximum benefit for treating dehydration safely and effectively.

World Health Organization information on ORS

Frequently Asked Questions

A standard oral rehydration solution contains water, glucose (sugar), and essential electrolytes such as sodium and potassium. These ingredients work together to enhance the body's fluid absorption.

While water is essential, plain water lacks the necessary electrolytes that the body loses during dehydration from conditions like diarrhea or vomiting. Drinking too much plain water can further dilute the body's electrolyte balance, potentially worsening the condition.

Homemade ORS should only be used as a temporary emergency measure when commercial packets are not available. It is crucial to measure ingredients accurately, as too much salt can be harmful and too much sugar can worsen diarrhea.

The World Health Organization (WHO) recommended formula for a homemade solution is one liter of clean water, six level teaspoons of sugar, and half a level teaspoon of salt.

Using contaminated water can introduce bacteria and other pathogens, making the ORS ineffective and potentially causing additional illness. It is essential to use clean, safe water, preferably boiled and cooled, for preparation.

Once mixed, the ORS should be covered and used within 24 hours. After this period, it should be discarded to avoid bacterial contamination.

While ORS is highly effective for mild to moderate dehydration, you should seek immediate medical attention for signs of severe dehydration, such as extreme fatigue, lack of urination, or unresponsiveness. Intravenous (IV) fluids may be necessary in these cases.