Glucola and the Oral Glucose Tolerance Test: What You Need to Know

Learn how the glucola test works to diagnose gestational diabetes, what to expect, and alternative options available.

By Medha deb

Created on Sep 25, 2025

Learn how the glucola test works to diagnose gestational diabetes, what to expect, and alternative options available.

What Is Glucola?

Glucola is a sweet, glucose-rich beverage used as part of the oral glucose tolerance test (OGTT). This test is a standard method for screening and diagnosing gestational diabetes, a condition that develops in some pregnant people when their bodies do not produce enough insulin to manage blood sugar levels during pregnancy.
Glucola contains a specific amount of glucose, typically 50, 75, or 100 grams, depending on the stage and type of test your provider recommends.

Purpose of the Glucola Test

The main purpose of the glucola test is to help healthcare professionals see how your body processes sugar. This test can detect gestational diabetes, which increases risks to both parent and baby if left unmanaged. Early detection is crucial to minimize complications such as:

High birth weight
Preterm delivery
Pre-eclampsia
Low blood sugar in newborns
Type 2 diabetes later in life for both mother and child

How Is the Test Performed?

The standard oral glucose tolerance test involves several steps:

Your provider asks you to fast overnight for 8–12 hours.
You arrive at the clinic or lab, and a baseline blood sample is taken to measure your fasting blood sugar.
Your provider gives you a Glucola drink, which you must consume within five minutes. The beverage is highly sweet and may be orange, lemon-lime, or another flavor.
Depending on the test, it contains either 50, 75, or 100 grams of glucose.
After drinking Glucola, your blood is drawn again at specific intervals—commonly at 1, 2, and possibly 3 hours after drinking.
These samples are analyzed to see how your blood sugar responds to the sugar load.

Test Duration

The typical one-hour screening test (sometimes called the glucose challenge test) involves drinking a 50-gram dose and having your blood checked an hour later.
If levels are above a certain range, a three-hour OGTT (with 100 grams of glucose and multiple blood draws) may follow for confirmation.

Why Do Pregnant People Take the Glucola Test?

Gestational diabetes often has no obvious symptoms. Risk factors can be present even in those without prior diabetes history. The glucola test allows providers to detect gestational diabetes reliably so it can be managed promptly. Guidelines generally suggest that all pregnant people take the screening test between weeks 24 and 28 of pregnancy, though some at-risk individuals may be tested earlier.
Risk factors for gestational diabetes include:

Pre-pregnancy overweight or obesity
Previous gestational diabetes
Family history of diabetes
Polycystic ovary syndrome (PCOS)
Advanced maternal age (over 25–30 years)
Belonging to certain racial or ethnic groups (e.g., African American, Hispanic, Native American, Asian)

How to Prepare for the Glucola Test

Preparation methods vary based on the test your provider orders. For the one-hour glucose challenge test, fasting is typically not required, though you may be asked to avoid high-sugar foods or drinks before coming in.

For the three-hour OGTT, you will usually need to fast for at least 8 hours before the test. Most people schedule this in the morning to make fasting easier.
You should:

Follow your provider’s guidance on diet, fasting, and medication use
Inform your healthcare professional about all medications, supplements, and recent illnesses—these can impact blood sugar readings
Refrain from strenuous exercise before the test
Arrive hydrated and wear comfortable clothing for easy blood draws

Medications and Other Factors

Certain medications and recent illnesses (like infection or surgery) can affect test results. Common medications that might interfere include corticosteroids, diuretics, and birth control pills.
Always discuss these with your doctor before the test.

Understanding Glucola Test Results

Your blood samples are measured for glucose levels at intervals after you drink the glucola beverage. Interpretation depends on the stage and type of test performed.

Test Type	Threshold for Concern	Diagnosis
1-hour (50g, screening)	≥ 135-140 mg/dL	Requires further testing
2-hour (75g, OGTT)	≥ 200 mg/dL after 2 hours	Gestational diabetes
3-hour (100g, OGTT)	Varies by draw—usually any 2 values above diagnostic thresholds	Gestational diabetes

If your result on the screening test exceeds the threshold, your healthcare provider will recommend the longer, more definitive test.
Two or more abnormally high readings on the three-hour test generally confirm gestational diabetes.

Managing Gestational Diabetes

If you are diagnosed with gestational diabetes, your provider will work with you to create a treatment plan. Managing blood sugar during pregnancy usually involves:

Following a healthy, balanced diet (emphasizing whole grains, vegetables, lean proteins)
Increasing physical activity as appropriate
Monitoring blood sugar levels regularly at home
Taking prescribed medication or insulin if needed
Attending more frequent prenatal appointments

Gestational diabetes often resolves after delivery, but people who have it may be at elevated risk for type 2 diabetes later in life. Ongoing monitoring and healthy lifestyle choices are important.

Possible Side Effects and Concerns

Most people tolerate the Glucola drink and test without significant issues. However, the beverage’s high sugar concentration can cause:

Nausea
Vomiting
Lightheadedness or stomach upset
Sweating or palpitations

If symptoms are severe and prevent you from finishing the drink, alert your provider right away—they may reschedule the test or offer alternatives.

Common Alternatives to Glucola

If you have allergies or cannot tolerate the glucola drink, discuss alternatives with your healthcare provider. Some alternatives include:

Eating a meal with equivalent carbohydrate content, checked at similar intervals
Using other commercially-available glucose solutions with different flavor profiles or organic ingredients
Using jelly beans or other measured candies containing a precise glucose dose
Employing continuous glucose monitoring (for those with known diabetes or special medical needs)

Always seek guidance before substituting, as accuracy and reliability are crucial for diabetes diagnosis and management.

Frequently Asked Questions (FAQs)

Q: Why do I need the glucola test if I feel healthy?

A: Gestational diabetes may cause few or no symptoms. The test helps ensure early detection and prompt treatment to prevent complications for you and your baby.

Q: What if I vomit after drinking glucola?

A: Alert your provider immediately. They may need to reschedule or select a different test protocol to ensure accurate results.

Q: Is it safe for my baby?

A: The amount of glucose in the beverage is considered safe. The risk from untreated gestational diabetes far outweighs the temporary sugar load from this test.

Q: Can I take the test at home?

A: No. The glucola test requires precise timing and blood samples, which must be handled in a clinical setting for accuracy.

Q: What happens after a gestational diabetes diagnosis?

A: Your provider will recommend dietary adjustments, exercise, sometimes medication, and more frequent prenatal checkups to monitor your health and your baby’s growth.

Key Takeaways

The Glucola test is a simple yet effective method to screen for gestational diabetes during pregnancy.
Most pregnant patients undergo screening between weeks 24 and 28.
Preparation may include fasting, medication review, and discussing recent illnesses with your provider.
Results guide important decisions about prenatal care and help protect long-term health for both mother and child.
Numerous alternatives exist for people who cannot tolerate Glucola, but all should be chosen in consultation with your healthcare team.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

Read full bio of medha deb