What does the glucose drink consist of? A breakdown of its ingredients

November 24, 2025 •

3 min read

Used widely in medical diagnostics, particularly for screening gestational diabetes, the oral glucose solution is a liquid containing a precise and high concentration of sugar. So, what does the glucose drink consist of? This article provides a comprehensive look into the core ingredients and additives of this unique diagnostic beverage.

Quick Summary

The standard glucose drink is primarily composed of purified water and a specific, concentrated dose of dextrose, a simple corn-derived sugar. Additional ingredients include citric acid for flavor and preservation, along with other artificial flavorings, colors, and preservatives depending on the brand and flavor.

Key Points

Core Ingredients: The primary components are purified water and a specific, high concentration of dextrose (glucose), often derived from corn.
Dextrose Concentration Varies: Depending on the test (screening or tolerance), the drink will contain 50, 75, or 100 grams of glucose.
Additives Improve Palatability: Citric acid, flavorings (e.g., orange, lemon-lime), and preservatives like sodium benzoate are added to balance the sweetness and extend shelf life.
Colors are Optional: Some flavored drinks include artificial colors (like FD&C Yellow #6), while unflavored or 'clean' versions are clear and dye-free.
Standardization is Key for Diagnostics: The pre-mixed, standardized nature of the drink ensures consistent dosing for accurate, reliable medical testing.
Alternatives Exist: For those with sensitivities, some brands offer versions with fewer additives, and in rare cases, approved food alternatives like jelly beans may be used.

The Core Components: A Simple Sugar Solution

At its heart, the glucose drink is a simple solution designed for a specific purpose: to provide a standardized, high dose of sugar to the body. The two primary ingredients are purified water and glucose.

Purified Water

Purpose: Provides the base for the solution, ensuring the glucose is easily ingested.
Type: Most formulations use purified, non-carbonated water.

Dextrose (Glucose)

Purpose: The single, concentrated carbohydrate source that challenges the body's ability to process sugar.
Source: Typically sourced from corn, it is a form of dextrose monohydrate and not high-fructose corn syrup.
Concentration: The amount of dextrose varies based on the test being performed. A one-hour screening test typically uses a 50-gram dose, while the more extensive tolerance test uses 75 or 100 grams.

The Supporting Cast: Additives and Flavorings

To make the drink more palatable and ensure its stability, manufacturers add several other ingredients. These additives often vary between brands and flavors.

Citric Acid

Purpose: Acts as a preservative and a flavoring agent.
Function: Provides a tart, acidic flavor that helps balance the overwhelming sweetness of the concentrated sugar. It also creates an acidic environment that inhibits microbial growth, which increases the drink's shelf life.

Preservatives

Purpose: To prevent spoilage and maintain freshness.
Examples: Common preservatives include sodium benzoate and potassium sorbate.

Flavoring Agents

Purpose: Mask the intense sweetness and make the drink easier to consume.
Examples: Artificial or natural flavorings are added to create popular varieties like orange, lemon-lime, or fruit punch.

Artificial Colors

Purpose: To give the flavored drinks a visually appealing appearance.
Examples: FD&C Yellow #6 is used for orange flavors, and FD&C Red #40 is used for fruit punch. Some brands offer colorless versions that omit these dyes.

Why a Standardized Drink is Used

Standardizing the composition is critical for diagnostic accuracy. Medical professionals rely on a consistent, known amount of glucose to properly measure a patient's glycemic response. Using a pre-measured, ready-to-drink solution eliminates the risk of human error from mixing or measuring the glucose and water, ensuring reliable test results. This consistency allows for a valid comparison of results across different patient populations and testing facilities.

Comparison of Standard vs. 'Clean' Glucose Drinks


Ingredient	Standard Flavored Glucose Drink	'Simply Pure' or 'Clean' Version
Dextrose (Glucose)	Yes (typically corn-derived)	Yes (often Non-GMO corn-derived)
Purified Water	Yes	Yes
Citric Acid	Yes	Often replaced with other flavorings like crystalized lemon
Preservatives	Yes (e.g., Sodium Benzoate)	Yes (e.g., Potassium Sorbate) or excluded
Flavoring	Yes (Artificial or Natural)	Minimal or natural flavoring (e.g., peppermint, lemon)
Artificial Colors	Yes (e.g., FD&C Yellow #6)	No, colorless

Alternatives and Patient Considerations

For patients with sensitivities or concerns about additives, some manufacturers and healthcare providers offer alternatives. As shown in the table, 'cleaner' versions of the glucose drink are available that contain fewer or more natural additives. Some sources even mention that alternatives like specific numbers of jelly beans have been tested, though this is not a universal standard and must be approved by a healthcare provider. It is important for patients to discuss any concerns with their doctor and to follow their specific instructions, as the test's validity depends on consuming the correct, measured dose of glucose.

Conclusion: A Tool for Medical Insight

While it may seem like a simple sugary beverage, the glucose drink is a carefully formulated medical tool. Its primary components—dextrose and purified water—are combined with flavorings, preservatives, and sometimes colors to ensure a standardized, palatable, and stable solution. Understanding what the glucose drink consist of sheds light on why it is a necessary and reliable part of screening for conditions like gestational diabetes. The specific ingredients serve to facilitate an accurate diagnostic procedure, providing critical information to healthcare professionals about a patient's metabolic function. For a detailed overview of the testing process itself, information from authoritative sources like the Cleveland Clinic website is invaluable.

Frequently Asked Questions

Dextrose is a simple sugar chemically identical to glucose and is the active ingredient in the drink. It is typically derived from corn and is used to provide the specific, concentrated dose of glucose required for the tolerance test.

Many brands of the standard flavored glucose drink contain artificial colors like FD&C Yellow #6 for orange flavors or FD&C Red #40 for fruit punch flavors. Colorless or 'clean' versions without these dyes are also available.

Citric acid is added for two main purposes: to act as a natural preservative by inhibiting microbial growth and to provide a tart, acidic flavor that offsets the intense sweetness of the glucose.

Most people describe the glucose drink as tasting like a very sweet, flat soda. The flavor is often compared to a sports drink or juice, but with a much higher sugar content that some find unpleasant or sickeningly sweet.

While it is possible to refuse, most medical associations and healthcare providers recommend undergoing the screening for gestational diabetes, as it is the standard method for diagnosis. Unmanaged gestational diabetes poses risks to both the mother and the fetus, making the screening an important part of prenatal care.

Some manufacturers offer alternative glucose drinks with fewer additives, such as natural flavorings or no artificial colors. Some clinics may also approve certain foods, like a specific number of jelly beans, as an alternative, but this must be confirmed with your doctor.

No, it is not recommended to make your own glucose solution at home. A specific, standardized concentration of glucose is required for accurate diagnostic results. Using an unverified dose could lead to an inaccurate test result and an incorrect diagnosis.