What is L-Methylfolate: Uses, Warnings & Interactions
Updated May 14,
2025 • Published Dec 30,
2020
L-methylfolate is the active form of folate (vitamin B9). Other versions of vitamin B9 such as folic acid have to be metabolized by the body into l-methylfolate before they can be used. Because l-methylfolate is the “ready-to-use” version of vitamin B9, manufacturers sell it as a better low-dose dietary supplement than other folate supplements. L-methylfolate is included in many prenatal vitamins and even in some birth control pills where it’s used as a backup prenatal supplement just in case the pill doesn’t work. In addition to low-dose dietary supplementation, research has shown that high-dose l-methylfolate can improve depression symptoms when added to antidepressants for treatment-resistant depression.
Low-dose l-methylfolate is a vitamin B9 dietary supplement for people who have low vitamin B9 levels, who are pregnant or breastfeeding, or who want to improve their health. Healthcare providers may also prescribe higher doses of l-methylfolate for folate deficiency, anemia, schizophrenia, or other conditions related to folate loss or metabolism. At very high doses, l-methylfolate is sometimes used as an add-on treatment with antidepressants for depression.
What form(s) does L-Methylfolate come in
Tablet
400 mcg
800 mcg
1 mg
7.5 mg
15 mg
Capsule
400 mcg
800 mcg
1 mg
2 mg
2.5 mg
5 mg
10 mg
7.5 mg
15 mg
Chewable tablet
800 mcg
1 mg
2.5 mg
5 mg
10 mg
Orally disintegrating tablet
1 mg
Gummies
1 mg
15 mg
Lozenge
800 mcg
Liquid drops
1 mg
15 mg
What are common L-Methylfolate doses?
Recommended daily intake:
For adults and adolescents 14 years of age and older: 400 mcg/day
For pregnant women: 600 mcg/day
For lactating women: 500 mcg/day
For children 9–13 years: 300 mcg/day
For children 4–8 years: 200 mcg/day
For children 1–3 years: 150 mcg/day
For children 7–12 months: 80 mcg/day
For newborns to children up to the age of 6 months: 65 mcg/day
For treatment-resistant depression along with antidepressants: 7.5 mg or 15 mg taken once daily
For high homocysteine levels in people with schizophrenia: 7.5 mg or 15 mg taken once daily
For folate deficiency: 400 mcg–1 mg taken daily
For megaloblastic anemia (folate deficiency without vitamin B12 deficiency): 1 mg daily
To prevent folate deficiency due to methotrexate chemotherapy: 5 mg taken once weekly
To prevent folate deficiency due to chronic hemodialysis: 1–5 mg taken once weekly
L-methylfolate can be taken with or without a doctor’s advice or prescription.
For self-administration, follow all the instructions on the product label.
When taking l-methylfolate under the direction of a healthcare professional, follow all the prescriber’s instructions.
The package directions or the prescriber will tell you how much to take each day. Do not use more than directed.
L-methylfolate doses can be taken with or without food.
Store l-methylfolate products at room temperature protected from heat and light.
What to do if you miss a dose of L-Methylfolate
Take a dose as soon as you remember.
If it’s the next day, skip the missed dose and resume the regular dosing schedule.
Do not take extra doses to make up for a missed dose.
L-Methylfolate contraindications
Do not use any l-methylfolate product if you have had an allergic reaction to the product or have a known allergy to any ingredient in the product.
L-Methylfolate warnings
Self-administering l-methylfolate supplements at doses lower than one milligram daily should not cause problems other than allergic reactions to ingredients in the product.
If self-administering l-methylfolate supplements, do not take high doses until talking to a doctor. Taking high doses of vitamin B9 can hide a vitamin B12 deficiency.
Before starting high-dose l-methylfolate (more than 1 mg daily), tell a doctor if you are pregnant, breastfeeding, or have:
A vitamin B12 deficiency
History of bipolar disorder (when used with an antidepressant)
When prescribed high-dose l-methylfolate, the doctor will need to check on the progress of treatment and occasionally perform blood tests. Keep all appointments.
Side effects are minimal even at high doses. The most commonly reported side effects are allergic reactions to ingredients in the product.
L-Methylfolate interactions
Folate supplements interact with many medications.
Before taking high-dose l-methylfolate, talk to a doctor first. Tell that doctor about all the prescription drugs, over-the-counter drugs, supplements, and remedies you take, particularly Prozac (fluoxetine), phenytoin, or capecitabine.
Other drugs lower folate levels in the body or interfere with folate metabolism. Some may not affect high-dose l-methylfolate. If you are taking prescription folate supplements, make sure the prescribing healthcare provider knows if you’re taking:
Drugs that treat seizures
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen
Oral contraceptives
Pancreatic enzymes
Commonly prescribed drugs such as the acne medication isotretinoin, the diabetes drug metformin, or methylprednisolone
