CPT: 83090

Expected Turnaround Time

24 Hours

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements


Serum, Plasma


SST (Serum), Red Top (Separate Serum), Lithium Heparin (Plasma), EDTA (Plasma), Sodium Heparin (Plasma),

Storage Instructions

Room Temp., Refrigerated (2-8 C)

Stability Requirements

Room temp. 5 days, Refrigerated 7 days

Test Details

Additional Information

Homocysteine is an amino acid derived from the metabolism of methionine, an essential amino acid obtained from the diet. In the body, homocysteine can be converted into other amino acids or recycled back to methionine with the help of certain B vitamins. Elevated levels of homocysteine in the blood are associated with an increased risk of cardiovascular and neurological diseases. Maintaining optimal homocysteine levels is crucial for overall health, as high levels can lead to inflammation and damage to blood vessels. 

Elevated homocysteine levels can indicate potential vitamin deficiencies or genetic factors that impair the body’s ability to metabolize this amino acid properly. By identifying and addressing the root causes of elevated homocysteine, functional medicine practitioners can develop targeted interventions, such as personalized nutrition plans and supplementation strategies, that optimize homocysteine levels and reduce the risk of related health issues. Understanding the importance of homocysteine in functional medicine allows healthcare providers to implement proactive measures, promoting overall wellness and preventing the onset of serious health conditions. Homocysteine is a sulfur-containing amino acid produced through the metabolism of methionine, an essential amino acid obtained from the diet. Homocysteine is involved in methylation, the transfer of a methyl group from one molecule to another. Methylation reactions are involved in numerous biological processes, including gene expression, protein function, neurotransmitter synthesis, and detoxification.  

The body tightly regulates the homocysteine levels in the body through the methionine-homocysteine cycle. Methionine is converted to S-adenosylmethionine (SAMe). SAMe, often called the body’s universal methyl donor, donates its methyl group to various substrates and is converted to S-adenosylhomocysteine (SAH). SAH is then converted to homocysteine.   

Homocysteine has two possible fates. It can be remethylated to methionine in a reaction that requires vitamin B12 and folate. Alternatively, it can enter the transsulfuration pathway to be converted to cysteine, a reaction that requires vitamin B6 and leads to the synthesis of glutathione 

A balance between these pathways is essential for maintaining proper levels of methionine and homocysteine in the body. Disruptions in this cycle can lead to elevated homocysteine levels (hyperhomocysteinemia). High homocysteine levels are associated with an increased risk for cardiovascular, cerebrovascular, and thromboembolic diseases. Therefore, understanding how homocysteine is produced in the body and its role in the methylation cycle is essential for maintaining proper biochemical balance and overall health.  


  1. Clarke, R., Halsey, J., Lewington, S., et al. (2010). Effects of Lowering Homocysteine Levels With B Vitamins on Cardiovascular Disease, Cancer, and Cause-Specific MortalityMeta-analysis of 8 Randomized Trials Involving 37 485 Individuals Effects of Lowering Homocysteine Levels. Archives of Internal Medicine, 170(18), 1622. https://doi.org/10.1001/archinternmed.2010.348 
  2. Rizzo, G. R., & Laganà, S. (2020). The Link between Homocysteine and Omega-3 Polyunsaturated Fatty Acid: Critical Appraisal and Future Directions. Biomolecules, 10(2), 219. https://doi.org/10.3390/biom10020219 
  3. Sharma P, Senthilkumar RD, Brahmachari V, et al. Mining literature for a comprehensive pathway analysis: A case study for retrieval of homocysteine related genes for genetic and epigenetic studies. Lipids Health Dis. 2006;5(1) doi: 10.1186/1476-511X-5-1. [PMC free article] [PubMed] [CrossRef] [Google Scholar] 

Statement on Medical Necessity
All ordered tests should be medically necessary for the diagnosis or detection of disease, illness, impairment, symptom, syndrome, or disorder and the results should be used in the medical management and treatment decisions for the patient. Solaris requires ICD-10 codes with each order for lab testing and both the tests ordered and the diagnosis should be documented in the provider’s medical record for the patient. The United States Department of Health and Human Services, Office of Inspector General, takes the position that a provider who orders medically unnecessary tests may be subject to civil penalties.

Panels and Profiles
Solaris offers Providers the convenience of ordering test combinations in a group at times with the flexibility to choose appropriate test(s) for individual patients. Providers should only order those tests that he or she believes are medically necessary for each patient, and a lesser inclusive profile or individual tests should be ordered if not all tests in the test combination/profile are medically necessary. All tests offered in a test combination/profile may be ordered separately as individual tests. Solaris encourages clients to contact their Solaris representative if the testing configurations shown do not meet individual needs for any reason, or if some other combination of procedures is needed.

CPT Codes
CPT Codes listed are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are the responsibility of the billing party and are listed here for informational purposes. Correct coding may vary from one carrier to another. Solaris may bill specific carriers using codes other than what is shown.


For questions or inquiries related to testing please reach out to
customerservice@solarisdx.com or contact us by phone at (844) 550-0308.