Skip to content

Serum Free Fructosamine

Published: August 9, 2026Updated: August 16, 2026

This test measures the average level of sugar (glucose) attached to proteins in your blood over the past 2–3 weeks. It helps assess how well your blood sugar has been controlled over time.

Quick summary

["A useful long-term measure of blood sugar control beyond just a single glucose reading."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47743-0
Short code
Serine SFr Hair
Synonyms
Serine SFr Hair
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

Unlike a single blood glucose test, which only shows your sugar level at that moment, free fructosamine gives a picture of how consistently your blood sugar has been managed. It’s particularly useful for people with diabetes or prediabetes to track trends over time.

What to Expect Before the Test

No special preparation is needed for this test. You’ll have a small needle inserted into your arm, and a few drops of blood will be drawn. The process takes just a few minutes.

How the Results Are Used

Your healthcare provider will use these results to see if your diabetes treatment plan is working. Higher levels may indicate periods of higher blood sugar, while lower levels might suggest better control.

Common Causes of Abnormal Results

Elevated levels could be due to poorly controlled diabetes, stress, illness, or certain medications. Lower levels might suggest over-treatment with insulin or other diabetes medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Free fructosamine is a marker of glycated proteins, reflecting average blood sugar levels over weeks. It complements immediate glucose checks by providing insight into chronic exposure to high or low sugar levels, helping adjust treatment strategies and reduce long-term risks like nerve damage or kidney issues.

Short name

Free Fructosamine

Frequently asked questions

What does a high free fructosamine level mean?
A high level suggests your blood sugar has been consistently higher than normal over the past few weeks, which may indicate poor diabetes management or other conditions affecting blood sugar.
What if my fructosamine level is low?
A low level may mean your blood sugar has been consistently lower than normal, possibly due to over-treatment with insulin or other diabetes medications. Your provider will work with you to balance your levels safely.
Does diet or exercise affect this test?
While diet and exercise influence daily blood sugar levels, they don’t directly affect fructosamine levels. However, they play a role in managing your overall blood sugar control, which indirectly impacts this test result.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy