Homocysteine

Fasting Required
CPT: 83090
Cardiovascular

What This Test Measures

Amino acid elevated in B-vitamin deficiency and MTHFR variants; independent cardiovascular risk factor.

Preparation

Fasting required (8-12 hours)
Fasting preferred. B vitamins (especially B12, B6, folate) significantly affect homocysteine — avoid supplementing for 48 hours before testing for a true baseline.
💬 Patient Community Notes

PREP: Fast 8–12 hours. Stop B vitamin supplements (B6, B12, folate/methylfolate) for at least 12 hours before the draw — these directly lower homocysteine and will mask a true elevation. The functional medicine community considers optimal homocysteine to be 6–8 µmol/L, much lower than the standard upper limit of ~15. Elevated homocysteine is seen as a marker of B12/folate insufficiency, methylation issues, or cardiovascular risk. For MTHFR patients, tracking homocysteine is considered essential. These notes reflect common practices in functional medicine communities.

Reflects common practices in thyroid, BHRT, and functional medicine communities. This may differ from standard clinical guidelines. Not medical advice — always discuss with your provider.

General guidelines only. Requirements vary by lab and individual. Confirm with your provider before adjusting any medications.

Turnaround Time

Varies by lab

Clinical Notes

Target <10 umol/L; elevated by low B12, B6, folate, and/or MTHFR variants

ICD-10 Codes

Common diagnosis codes associated with this test. Codes are assigned by your provider.

D51.9Vitamin B12 deficiency anemia, unspecified
E11.9Type 2 diabetes mellitus without complications
I25.10Atherosclerotic heart disease of native coronary artery without angina pectoris

Self-Pay Pricing

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Ulta Lab Tests

Uses Quest Diagnostics network; generally lowest DTC prices; not available in NY, NJ, RI

$36.95Order
Personalabs

Uses Quest and Labcorp; no hidden draw or facility fees; moderate pricing

$40.00Order
Life Extension

Uses Labcorp network; known for supplement company; competitive lab test pricing

$55.00Order
QuestDirect

Quest Diagnostics consumer-direct platform; results in 1-2 days; 2,100+ locations nationwide

$55.85Order
DirectLabs

Uses Quest Diagnostics network; good panel pricing; established DTC provider

$56.25Order
Walk-In Lab

Uses both Quest and Labcorp networks; competitive pricing; broad test selection

$59.00Order
Labcorp OnDemand

Labcorp consumer-direct platform; 2,000+ locations; results in 1-3 days

$59.00Order
Request A Test

Uses Quest and Labcorp networks; offers both individual tests and discounted panels

$69.00Order
HealthLabs.com

Uses Quest and Labcorp; strong panel bundling; results in 1-3 days

$99.00Order

Lab Codes

Proprietary codes used by each lab for this test.

American Esoteric Labs
E047(order_code)
ARUP Laboratories
0070078(order_code)
BioReference Laboratories
1311-0(order_code)
Cleveland Clinic
HOMO(mnemonic)
Clinical Labs of Hawaii
6828(order_code)
CPL
4288(order_code)
Geisinger Medical Labs
LAB2493(lab_id)
Interpath Laboratory
2224(order_code)
LabCorp
501700(order_code)
LabCorp
706994(order_code)
Mayo Clinic Labs
HCYSP/9068(order_code)
Northwell Health Labs
5900785(order_code)
NYU Langone Health
LAB93(order_code)
Quest Diagnostics
31789(order_code)
Stanford Health Care
HMCY(order_code)

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For informational purposes only

This page is for educational and research purposes only and does not constitute medical advice, diagnosis, or treatment recommendations. ICD-10 and CPT codes are assigned by your healthcare provider. Always consult a qualified healthcare provider before ordering any lab test or making decisions about your health.