Skip to content

Tamoxifen Concentration in Serum/Plasma (Quantitative)

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

This test measures the amount of tamoxifen, a medication used to treat certain types of breast cancer, in your blood.

Quick summary

["Understanding your tamoxifen levels helps your doctor monitor your treatment effectiveness and adjust your dose if needed."]

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

Key facts at a glance

LOINC
73130-7
Short code
Tamoxifen ind plt IgM SerPl Ql FC
Synonyms
Tamoxifen ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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 Is This Test Done?

Your doctor may order this test to check if your tamoxifen levels are within the recommended range. This helps ensure the medication is working properly and avoids potential side effects from too much or too little in your system.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if instructed by your healthcare provider, but this is not always required. Bring a list of all medications, including over-the-counter drugs and supplements, to your appointment.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What the Results Mean

Your results will show the concentration of tamoxifen in your blood. While specific ranges vary by treatment plan, lower-than-expected levels may indicate the medication isn’t being absorbed well, while higher-than-expected levels may require dose adjustments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Tamoxifen Level

Frequently asked questions

How often should I get this test?
Your doctor will determine the timing based on your treatment schedule. Typically, tests may be done at regular intervals (e.g., every 2–4 weeks) during active treatment to monitor levels and adjust your dose as needed.
What if my levels are too high or too low?
If your tamoxifen levels are too low, your doctor may increase your dose or switch to a different form of the medication. If levels are too high, they may reduce your dose or temporarily pause treatment to prevent side effects like hot flashes, nausea, or bone loss.
Can I drink alcohol before this test?
Alcohol may not affect tamoxifen testing, but it’s best to avoid it before blood draws if you’re experiencing side effects like nausea. Always follow your doctor’s specific instructions for test preparation.
  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