Curious about the jumble of almost NSFW letters trending in the wellness world? You’ve come to the right place. We’re about to do a deep dive into MTHFR genetic variants.


MTHFR = methylenetetrahydrofolate reductase. The MTHFR gene is in charge of breaking down homocysteine, an amino acid.

A mutation in your MTHFR gene may lead to low vitamin B-12 and folate levels and high homocysteine levels. This *might* increase your risk of experiencing blood clots, thyroid conditions, and developmental issues for a fetus.

So far, researchers aren’t sure about the exact impact of MTHFR mutations. It doesn’t seem to indicate a major cause for concern for most folks.

Was this helpful?
Share on Pinterest
Photographer: Heather Hazzan; Wardrobe: Ronald Burton; Props: Campbell Pearson; Hair: Hide Suzuki; Makeup: Deanna Melluso at See Management. Shot on location at One Medical.

MTHFR stands for methylenetetrahydrofolate reductase. It’s an enzyme that helps your body process an amino acid called homocysteine. When we talk about the MTHFR gene, we’re talking about the gene that’s responsible for creating that enzyme.

Everyone has two MTHFR genes — one from each parent. Some folks have a mutation on just one MTHFR gene, while others have it on both (a double variant.)

There are two common types of MTHFR variations:

  • C677T. Research says that in North America, this mutation is commonly present in more than 25 percent of Hispanic people and 10 to 15 percent of white people.
  • A1298C. According to the American Heart Association, this mutation is commonly present in 7 to 13 percent of white people and 4 to 5 percent of Hispanic people.

It sounds pretty scifi, but MTHFR mutations don’t give you superpowers. Instead, they affect your body’s ability to break down homocysteine.

*Sometimes* this becomes a concern because super high homocysteine levels can lead to:

FYI: It’s important to note that the stress of enduring racism and racist systems may play a part in how you experience the health effects from the mutations beyond genetic factors.

When folks talk about MTHFR deficiencies, they’re just referring to the result of an MTHFR variant.

If one or both of your MTHFR genes has a mutation, your body might not produce enough methylenetetrahydrofolate reductase. That means you have an MTHFR deficiency.

An MTHFR mutation itself won’t cause symptoms. Most folks with an MTHFR mutation don’t even know they have it.

MTHFR *might* cause high homocysteine levels, though. And that can increase your risk of developing several health conditions.

Some conditions with potential links to MTHFR include:

Your risk of experiencing the above conditions might be higher if you have two MTHFR mutations.

Here’s another question to consider first: Do you even need to get tested?

The Genetic and Rare Diseases Information Center (GARD) says that many health experts recommend against genetic testing. Not because it’s harmful, but because it’s unnecessary.

If you have high homocysteine levels or some other indication of an MTHFR prob, your doctor might order blood tests for genetic variants.

Still curious? You can snag a DIY test here:

  • 23andMe. Yep, these ancestry tests also scan genetic markers for everything from cilantro taste aversion to MTHFR variants. You’ll get all that for coughing up around $200 (and a spitting up a sample of saliva.)
  • My Home MTHFR. This MTHFR-only test uses DNA from a cheek swab.

If your MTHFR variant isn’t causing health concerns, there’s nothing to treat. But if you’re experiencing very high homocysteine levels and your doctor says it’s because of a genetic mutation, you’ll probably be given supplements (and maybe medications).

Keep in mind, high homocysteine can be caused by things other than a genetic variant, including:

If you have a confirmed MTHFR mutation and want to do your best to prevent unstable homocysteine levels, try these lifestyle changes:

  1. Start a regular fitness routine.
  2. Nosh on whole foods. (Aim for a balanced, nutritious diet overall.)
  3. Try to stop smoking (if you do!).

What about supplements for MTHFR?

An MTHFR mutation can affect your body’s ability to absorb specific vitamins. So, if you have abnormally high homocysteine levels, your doc might recommend these supplements:

🚨 PSA: Talk with your healthcare professional before taking these supplements. High homocysteine could indicate other health conditions, so you’ll need a diagnosis first. 🚨

Was this helpful?

Let’s say you *do* have an MTHFR genetic mutation. That puts you at risk of developing high homocysteine and low folate levels.

Eating folate-rich foods might help you keep your levels in the safe zone. Here are some excellent options.

There’s not much evidence to back up the claim, but some folks recommend avoiding synthetic folate (known as folic acid) if you have an MTHFR mutation. You’ll find folic acid in enriched bread, cereals, flours, and pasta.

Research shows that women with *two* MTHFR variants are twice as likely to have babies with a neural tube defect (NTD). This can lead to conditions like:

  • spina bifida: a condition in which the spine or spinal cord grows incorrectly
  • anencephaly: a condition in which part of the brain is missing
  • encephalocele: a condition in which there’s an opening in the skull
  • iniencephaly: a condition in which the neck and spine are severely misshapen

If this has your heart racing, take a deep breath. NTDs are super, super rare.

According to the Genetic and Rare Disease Information Center, the risk of developing NTDs is only 0.14 percent with an MTHFR mutation.

A 2006 study did link recurrent miscarriage with double genetic mutations, and MTHFR was included in the list.

Bottom line? Talk with your doctor if…

  • you had more than one unexplained miscarriage
  • you carried a baby with an NTD
  • you’re pregnant, and you know you have the MTHFR mutation

Plenty of folks with MTHFR variants never know it. The most common signs are high homocysteine levels and folate or vitamin B-12 deficiencies.

Here are the symptoms of a deficiency:

  • chronic fatigue
  • shortness of breath
  • general weakness
  • tingling or pain in your hands and feet
  • dizziness
  • mouth sores
  • constipation, loss of appetite, or unexplained weight loss
  • changes in mood

Remember, these can be symptoms of other health conditions and vitamin deficiencies. Only a doctor can help you get to the root of the concern.

Does the status of your MTHFR genes matter? Maybe, but probably not. Researchers are still figuring out the impact (if any) of MTHFR variants.

In general, there’s no need to get tested for an MTHFR mutation. If you’re having health concerns and your doctor suspects a genetic condition, they’ll order tests to find out.