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Nootropics>Vitamins & vitamin-like compounds>L-5-MTHF
Vitamins & vitamin-like compounds

L-5-MTHF

L-5-MTHF (reduced methylfolate vitamer)

L-5-MTHF is the biologically reduced methylfolate vitamer sold in several salt forms; for a useful product comparison, check the full salt name, folate equivalence, combined supplemental folate, and whether pregnancy guidance specifically calls for folic acid.

Water SolubleClinical ResearchForm Dependent EvidenceLow Risk Profile
Updated August 2026/4 min read/3 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

Identity and form

1

L-5-MTHF is the biologically reduced methylfolate vitamer sold in several salt forms.

Pregnancy and preconception2
The pregnancy RDA is 600 mcg DFE. In the United States, people capable of becoming pregnant are advised to obtain 400-800 mcg/day folic acid in addition to food folate; folic acid is the form with direct evidence for neural-tube-defect risk reduction, and this evidence should not be assumed for 5-MTHF.
02

Names, aliases and forms

Common NameMethylfolate
Chemical NameL-5-methyltetrahydrofolate
Abbreviation5-MTHF
03

Mechanisms of action

Biological role

1

It can donate methyl groups within folate-dependent one-carbon metabolism.

04

Potential effects and evidence map

Evidence is strong for the essential nutrient role of folate, but supplementation beyond adequacy has not been shown to produce a reliable general nootropic effect in well-nourished adults. Form-specific clinical uses should be evaluated separately.

Effect domainMagnitudeGrade
Mental energy / wakefulness1
UnknownConfidence: Medium

Evidence does not establish a reliable mental-energy effect from extra L-5-MTHF in well-nourished healthy adults.

Note Essential nutrient biology and correction of inadequate status are different from enhancement.

1/5
C
Memory / learning1
UnknownConfidence: Medium

Direct evidence does not establish a general memory or learning benefit from L-5-MTHF for healthy adults.

Note Keep form- and population-specific clinical research separate.

0/5
C
05

Typical dosages and timing

Nutrition benchmark1400 mcg DFE/day

Use this to interpret labels and total intake, not as a demonstrated nootropic dose or recommended cycle.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
What timing evidence can show1

No reliable acute nootropic onset, duration, The time for blood levels to fall by half during the final elimination phase.Source claim, or routine cycle is established for L-5-MTHF. Nutrient-status correction and clinical follow-up periods answer different questions.

07

Safety, side effects and risk profile

Evidence uncertainty1
Confidence: High

Marketing claims extend beyond the established nutrient or precursor evidence.

Note Separate adequacy, biochemical activity, and enhancement outcomes.

1/5
B
Interaction risk1
Confidence: Medium

Medication, laboratory, and total-intake context can change the practical risk.

Note Check the official source for ingredient-specific interaction details.

1/5
B
GI discomfort1
Confidence: Medium

Tolerability varies with the specific form and amount consumed.

Note This row summarizes ordinary tolerability rather than special-population hazards.

1/5
B
Dose- and form-specific safety1

EFSA found an assessed sodium salt safe under proposed conditions when combined supplemental folate remains below established upper levels; this does not make every salt or high dose interchangeable.

08

Interactions and cautions

Medication and test context3

Folate forms can interact with antifolate and antiepileptic medicines; prescription methylfolate contexts are not ordinary supplement guidance.

09

Practical buying and quality notes

  • Check the full salt name, folate equivalence, combined supplemental folate, and whether pregnancy guidance specifically calls for folic acid.1
10

FAQ

What distinguishes L-5-MTHF from related forms?

1

Evidence and authorized conditions can be salt-specific; an EFSA opinion on monosodium L-5-MTHF does not make all salts or doses interchangeable.

11

References

  1. EFSA NDA Panel. Safety and bioavailability of monosodium L-5-methyltetrahydrofolate. 2023.
  2. NIH Office of Dietary Supplements. Dietary Supplements and Life Stages: Pregnancy Fact Sheet for Health Professionals.
  3. NIH Office of Dietary Supplements. Folate Fact Sheet for Health Professionals.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.