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Vitamin

Methylfolate (L-5-MTHF)

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Methylfolate (L-5-MTHF). Bioactive folate that bypasses the MTHFR enzyme — preferred in MTHFR variants and pregnancy.

How it works. Skips dihydrofolate reductase and MTHFR — directly enters the methylation cycle as 5-MTHF.

What the research supports. 2 graded claims. Strongest: Prevents NTDs in pregnancy (strong).

How much to take. Typical dose: 400–1000 mcg DFE.

Side effects and interactions. 1 medication interaction listed. No serious side effects listed at normal doses.

Stacking. Pairs well with Methylcobalamin (B12).

Common forms. Available as Capsule or softgel, Sublingual tablet or liquid, Methylated active form for sensitive individuals, Multivitamin matrix.

Key studies. 9 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Methylfolate (L-5-MTHF). Anecdotes are not medical advice.

Methylfolate (L-5-MTHF). Bioactive folate that bypasses the MTHFR enzyme — preferred in MTHFR variants and pregnancy.

Molecular structureC20H21N7O6 · 455.4 g/mol

What it is

Bioactive folate that bypasses the MTHFR enzyme — preferred in MTHFR variants and pregnancy.

Also called

L-methylfolateQuatrefolicMetafolin

Food sources

Whole-food sources (animal products for fat-soluble and B-complex vitamins; produce for water-soluble vitamins)Fortified foods (cereals, dairy, plant milks, nutritional yeast)Multivitamins or stand-alone supplements in synthetic or food-derived form

Goals

Mood & AnxietyFertilityWomen's HealthBrain & Cognitive

How it works

Skips dihydrofolate reductase and MTHFR — directly enters the methylation cycle as 5-MTHF.

Pathways

  • Methylation cycle
  • Homocysteine remethylation
  • Monoamine synthesis (BH4)

Effects

  • +Augments SSRI response in depression supports
  • ↓NTDs in pregnancy decreases

What the research supports

Prevents NTDs in pregnancystrong
Augments SSRI response in depressionmoderate

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
400–1000 mcg DFE
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodOptional
Best formMost evidence is based on the capsule or softgel form.
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Side effects & interactions

Common side effects

  • Anxiety/insomnia in overmethylators

Medication interactions

Prescription medications (general)minor

Always disclose Methylfolate (L-5-MTHF) use to your prescriber — additive, antagonistic, or pharmacokinetic interactions are possible.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Methylcobalamin (B12)Methyl trap prevention.

Common forms

  • Capsule or softgel
  • Sublingual tablet or liquid
  • Methylated active form for sensitive individuals
  • Multivitamin matrix

Key studies

9 studies cited in total.

PubMed: Methylfolate (L-5-MTHF) — Augments SSRI response in depression ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Methylfolate (L-5-MTHF) and "Augments SSRI response in depression". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Methylfolate (L-5-MTHF) — Prevents NTDs in pregnancy ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Methylfolate (L-5-MTHF) and "Prevents NTDs in pregnancy". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Methylfolate (L-5-MTHF) — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Methylfolate (L-5-MTHF) and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

Discussion

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