5-MTHF vs L-Methylfolate – What Are the Differences and Which One to Choose?

5-MTHF vs L-Methylfolate – What Are the Differences and Which One to Choose?

If you’ve ever stood in front of a supplement shelf (or scrolled through endless product pages online) trying to figure out the difference between 5-MTHF, L-Methylfolate, methylfolate, and a dozen other terms – you’re not alone. The world of B vitamins can feel like alphabet soup, and folate supplements are particularly confusing.

Here’s the good news: once you understand a few key concepts, it all starts to make sense. And spoiler alert – some of these intimidating-sounding names are actually just different ways of describing the same thing. Let’s break it down in plain English.

First Things First: What Even Is Folate?

Folate is vitamin B9 – one of those essential nutrients your body needs but can’t produce on its own. You’ll find it naturally in leafy greens, legumes, and citrus fruits. The synthetic version, which you’ll see in fortified foods and many basic supplements, is called folic acid.

But here’s where it gets interesting. Your body can’t actually use folic acid directly. It needs to convert it into an active form first – and that active form is called 5-MTHF (or, as you might have guessed, L-Methylfolate). Think of folic acid as the raw ingredient and 5-MTHF as the ready-to-use version.

What Exactly Is 5-MTHF?

5-MTHF stands for 5-Methyltetrahydrofolate. Yes, it’s a mouthful. But the concept is simple: this is the biologically active form of folate – the version your cells can actually put to work immediately, no conversion required.

When you eat folate-rich foods or take a folic acid supplement, your body runs it through a conversion process involving an enzyme called MTHFR (methylenetetrahydrofolate reductase). The end product of that process? You guessed it – 5-MTHF [1].

Now, here’s something worth knowing: research published in Circulation indicates that approximately 20-40% of Caucasian and Hispanic individuals in the United States carry at least one copy of the MTHFR C677T variant [2]. In people who are heterozygous (carrying one copy), enzyme function is reduced to around 65% of normal. Those who are homozygous (carrying two copies) retain only about 30% of normal enzyme function [2]. This is one reason why supplements containing pre-converted 5-MTHF have become increasingly popular over the past decade.

And What About L-Methylfolate?

Here’s the part that confuses most people – and where we can clear things up quickly. L-Methylfolate and 5-MTHF are the same substance. They’re just different names for the same molecule.

The “L” in L-Methylfolate refers to the molecule’s optical configuration – essentially, its three-dimensional shape. Molecules can exist in mirror-image forms (like your left and right hands), and the “L” form is the one that occurs naturally in your body and that your cells recognise and use. The “5-MTHF” name describes the chemical structure more precisely, which is why scientists prefer it in research papers. Supplement manufacturers tend to use “L-Methylfolate” because it’s a bit easier to read on a label.

So when you’re comparing products and see one listing “5-MTHF” and another listing “L-Methylfolate” – relax. You’re looking at the same thing.

The Stereoisomer Question: Why (6S) Matters

If you want to get a bit more technical (and this is genuinely useful when comparing supplement quality), there’s one more detail worth understanding.

5-MTHF can exist in two mirror-image forms: (6S)-5-MTHF and (6R)-5-MTHF. Only the (6S) form is biologically active – it’s the form your body naturally produces and uses. The (6R) form? Your body essentially ignores it.

Some cheaper methylfolate supplements contain a 50/50 mixture of both forms, which means you’re only getting half the active ingredient you think you’re paying for. Higher-quality supplements specify that they contain exclusively the (6S) form. This is where branded ingredients like Quatrefolic® come in – it’s a patented form that guarantees you’re getting pure (6S)-5-MTHF, specifically as a glucosamine salt that offers enhanced stability and water solubility [3].

What Does the Science Say?

The European Food Safety Authority (EFSA) has thoroughly evaluated (6S)-5-methyltetrahydrofolic acid glucosamine salt (the form used in Quatrefolic®) and confirmed its safety and bioavailability for use in food supplements [3]. A crossover comparative bioavailability study in human volunteers demonstrated that folate from the glucosamine salt exhibited similar bioavailability to folate from the calcium salt form [3].

Further research published in 2022 by EFSA’s NDA Panel concluded that at doses of 400 µg per day or higher, 5-MTHF is actually more bioavailable than folic acid, with a proposed conversion factor of 2.0 (compared to 1.7 for folic acid) relative to natural food folate [4]. In practical terms, this means you may get more usable folate from a 5-MTHF supplement than from the equivalent dose of folic acid.

What Does Folate Actually Do in Your Body?

Folate isn’t just another vitamin to tick off your list – it’s involved in some genuinely fundamental processes. According to the EU Register of authorised health claims [5], folate:

• Contributes to normal cell division – essential for tissue growth and repair throughout your body
• Contributes to maternal tissue growth during pregnancy – one of the most well-established roles for folate
• Contributes to normal amino acid synthesis – the building blocks of proteins
• Contributes to normal blood formation – supporting the production of red blood cells
• Contributes to normal homocysteine metabolism – helping regulate this amino acid in your bloodstream
• Contributes to normal psychological function – yes, your brain needs folate too
• Contributes to the reduction of tiredness and fatigue
• Contributes to the normal function of the immune system

For women who are planning a pregnancy or in early pregnancy, there’s an additional important point: supplemental folate intake increases maternal folate status. Low maternal folate status is a risk factor in the development of neural tube defects in the developing foetus [6]. This is why folate supplementation is so widely recommended before and during pregnancy.

How to Choose a Methylfolate Supplement

Not all methylfolate supplements are created equal. When you’re comparing options, here are a few things worth checking:

Look for the (6S) form. As mentioned above, this is the biologically active stereoisomer. Products using Quatrefolic® or similar branded ingredients will specify this.

Check the actual folate content. Some labels can be confusing – make sure you know whether the stated amount refers to the total compound or the active folate equivalent.

Consider the dosage. A typical supplemental dose ranges from 400 to 800 µg, depending on your individual needs. If you’re unsure what’s appropriate for you, it’s worth having a conversation with a healthcare professional.

Our Recommendation: Capsure Methyl Folate Quatrefolic® 600 mcg

If you’re looking for a straightforward, high-quality methylfolate supplement, Capsure Methyl Folate Quatrefolic 600 mcg ticks all the boxes. It features Quatrefolic® – the patented glucosamine salt of (6S)-5-MTHF developed by Gnosis by Lesaffre – which means you’re getting exclusively the active form with excellent bioavailability and stability.

Each capsule provides 600 µg of active folate, manufactured to GMP standards, and free from artificial colours and preservatives. The recommended dose is one capsule daily, ideally taken with food.

The Bottom Line

Let’s recap the essentials. 5-MTHF and L-Methylfolate are two names for the same molecule – the active form of folate that your body can use directly without conversion. When choosing a supplement, the key things to look for are the (6S) stereoisomer (the only biologically active form) and a reputable branded ingredient like Quatrefolic® that guarantees purity and stability.

Folate plays crucial roles in everything from cell division to psychological function, and ensuring adequate intake is particularly important for women before and during pregnancy. Whether you opt for dietary sources, fortified foods, or supplements, the important thing is making sure your body has access to this essential nutrient in a form it can actually use.

Frequently Asked Questions

Is 5-MTHF better than folic acid?

5-MTHF is the active form that bypasses the MTHFR conversion step. For individuals with common MTHFR gene variants who may convert folic acid less efficiently, 5-MTHF offers a more direct route. EFSA has concluded that at doses of 400 µg/day or higher, 5-MTHF is more bioavailable than folic acid [4].

Can I use L-Methylfolate during pregnancy?

Absolutely. Methylfolate is an appropriate and widely-used form of folate supplementation during pregnancy. The key is ensuring adequate intake – supplemental folate increases maternal folate status, which is important both before conception and during early pregnancy for supporting foetal development [6].

What’s the difference between folate and folic acid?

Folate is the umbrella term for vitamin B9, including forms found naturally in food. Folic acid is the synthetic form used in fortified foods and many supplements. Your body converts folic acid into active folate (5-MTHF), but this conversion varies in efficiency from person to person depending on their genetic makeup [2].

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References

1. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to folate. EFSA Journal 2010;8(10):1760. Available at: https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1760
   
   
2. Moll S, Varga EA. Homocysteine and MTHFR Mutations. Circulation 2015;132(1):e6-e9. doi:10.1161/CIRCULATIONAHA.114.013311. Available at: https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.114.013311
   
   
3. EFSA Panel on Food Additives and Nutrient Sources (ANS). Scientific Opinion on (6S)-5-methyltetrahydrofolic acid, glucosamine salt as a source of folate added for nutritional purposes to food supplements. EFSA Journal 2013;11(10):3358. Available at: https://www.efsa.europa.eu/en/efsajournal/pub/3358
   
   
4. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA). Conversion of calcium-L-methylfolate and (6S)-5-methyltetrahydrofolic acid glucosamine salt into dietary folate equivalents. EFSA Journal 2022;20(8):7452. Available at: https://www.efsa.europa.eu/en/efsajournal/pub/7452
   
   
5. European Commission. EU Register of Nutrition and Health Claims. Commission Regulation (EU) 432/2012. Available at: https://food.ec.europa.eu/food-safety/labelling-and-nutrition/nutrition-and-health-claims/eu-register-health-claims_en
   
   
6. Commission Regulation (EU) No 1135/2014 of 24 October 2014 on the authorisation of a health claim made on foods, other than those referring to the reduction of disease risk and to children’s development and health (neural tube defects). Official Journal of the European Union L 307/134. Available at: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014R1135
   
   
7. Miraglia N, et al. Enhanced oral bioavailability of a novel folate salt: comparison with folic acid and a calcium folate salt in a pharmacokinetic study in rats. Minerva Ginecologica 2016;68(1):33-43. PMID: 27008238. Available at: https://pubmed.ncbi.nlm.nih.gov/27008238/
   
   
8. Levin BL, Varga E. MTHFR: Addressing Genetic Counseling Dilemmas Using Evidence-Based Literature. Journal of Genetic Counseling 2016;25(5):901-911. doi:10.1007/s10897-016-9956-7. Available at: https://onlinelibrary.wiley.com/doi/full/10.1007/s10897-016-9956-7
   
   
9. Scaglione F, Panzavolta G. Folate, folic acid and 5-methyltetrahydrofolate are not the same thing. Xenobiotica 2014;44(5):480-488. doi:10.3109/00498254.2013.845705.
   
   
10. Obeid R, Holzgreve W, Pietrzik K. Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects? Journal of Perinatal Medicine 2013;41(5):469-483. doi:10.1515/jpm-2012-0256.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. If you have any health concerns or are taking medication, consult a healthcare professional before starting any supplement.