You can find your MTHFR status on 23andMe in two ways: by using the built-in raw data browser to search for MTHFR directly, or by downloading your raw data file and running it through a third-party tool. As of 2025, 23andMe also added a dedicated report on MTHFR-related homocysteine levels for some members, but the raw data method works for everyone.
Use the Raw Data Browser (No Download Needed)
The fastest way to check your MTHFR variants is the Browse Raw Data tool built into 23andMe’s website. To get there, log into your account, click your profile name in the top right corner, and select “Resources” from the dropdown menu. Then click “Browse Raw Genotyping Data.”
Once you’re on that page, you’ll see a search box above a chromosome graphic. Type “MTHFR” into the search box. The tool will display all the MTHFR markers that 23andMe tested on your chip. Each row shows the marker’s rsID (a standardized reference number), its position on the chromosome, and your genotype, which is the pair of letters representing what you inherited from each parent.
The two markers you’re looking for are:
- rs1801133 for the C677T variant
- rs1801131 for the A1298C variant
If either marker doesn’t appear when you search, it means your particular genotyping chip version didn’t include it. This is uncommon for rs1801133 but does happen occasionally with rs1801131.
How to Read Your Genotype
23andMe reports genotypes using the letters of the DNA bases it reads. For the MTHFR markers, these letters map to specific variants, but the way 23andMe displays them can be confusing because it reads the opposite strand of DNA for some markers. Here’s how to interpret what you see.
C677T (rs1801133)
23andMe typically reports this marker on the reverse strand, so you’ll see A’s and G’s instead of C’s and T’s. The translation is straightforward: G corresponds to the “normal” C allele, and A corresponds to the T variant.
- GG = CC genotype (no variant copies)
- AG = CT genotype (one variant copy, heterozygous)
- AA = TT genotype (two variant copies, homozygous)
A1298C (rs1801131)
This one is also often reported on the reverse strand. You’ll see T’s and G’s:
- TT = AA genotype (no variant copies)
- GT = AC genotype (one variant copy, heterozygous)
- GG = CC genotype (two variant copies, homozygous)
If the strand orientation feels confusing, a third-party analysis tool (covered below) will translate this for you automatically.
Download Your Raw Data File
If you’d rather use an outside tool to analyze your results, or if you want a permanent copy of your genetic data, you can download the full raw data file. You can go directly to you.23andme.com/tools/data/, or navigate through Account Settings and click “View” under “23andMe Data.”
You’ll need to confirm your date of birth, read through a disclosure, check a consent box, and click “Submit request.” 23andMe then generates a file, which can take a few minutes. The file arrives as a zipped text document containing every marker they tested, including your MTHFR variants. You can open it in a spreadsheet program and search for rs1801133 or rs1801131, or upload the whole file to a third-party service.
Third-Party Analysis Tools
Several free services will read your 23andMe raw data file and produce a clean report of your MTHFR status along with related methylation genes. Genetic Genie is one of the most widely used. It accepts raw data files from 23andMe and other testing companies, and it translates the strand orientation for you so you see results labeled clearly as C677T and A1298C with plain-language genotype calls.
These tools typically flag whether you’re homozygous, heterozygous, or have no variant copies for each MTHFR position. Some also analyze additional genes in the same metabolic pathway. The advantage over manually searching your raw data is that you skip the strand-translation step entirely and get a formatted summary.
23andMe’s Built-In MTHFR Report
In 2025, 23andMe added a report called “Homocysteine (MTHFR-Related)” to its health offerings. This report examines common MTHFR variants associated with slightly increased homocysteine levels in the blood. If you have access to this report (it may require a 23andMe+ membership), you can find it in your health reports section without needing to dig through raw data at all. It provides an interpreted result rather than just the raw genotype letters.
What Your MTHFR Results Actually Mean
MTHFR variants are extremely common. The C677T variant is the most studied, and even the homozygous TT genotype (two copies of the variant) only reduces blood folate levels by about 16% compared to people with no variant copies, when both groups get the same amount of folic acid. That’s a real but modest difference.
The CDC states plainly that people with MTHFR variants can process all types of folate, including folic acid. Getting 400 mcg of folic acid daily raises blood folate levels regardless of MTHFR genotype, and common MTHFR variants are not a reason to avoid folic acid. Your actual folate intake matters more than your genotype in determining how much folate ends up in your blood.
The A1298C variant has even less clinical significance. There isn’t enough evidence to show that this variant alone meaningfully affects how your body processes folate. If you’re heterozygous or even homozygous for A1298C, the practical impact on your health is unclear.
Many wellness practitioners treat MTHFR variants as a major health concern requiring specialized supplements. The research doesn’t support that framing for most people. Knowing your MTHFR status can be interesting and occasionally relevant, particularly during pregnancy planning, but it’s not the metabolic emergency it’s sometimes made out to be online.