Doctor's Best Fully Active Folate with Quatrefolic® 400mcg delivers folate in the bioactive methylated form — (6S)-5-methyltetrahydrofolate (5-MTHF) — bypassing the metabolic conversion step that up to 40% of people cannot perform efficiently due to MTHFR gene variants. Unlike folic acid, which requires conversion to the active form through the enzyme MTHFR, Quatrefolic® 5-MTHF is immediately bioavailable and ready for use by the body.*

• Quatrefolic® — patented, methylated, bioactive 5-MTHF folate*
• Bypasses MTHFR conversion — suitable for MTHFR variants*
• Supports healthy homocysteine metabolism*
• Supports foetal neural tube development during pregnancy*
• Supports cardiovascular health and methylation pathways*
• Non-GMO | Gluten Free | Vegan | 90 veggie capsules

Suggested Use: As a dietary supplement, take 1 capsule daily with a meal, or as directed by your healthcare professional.

Frequently Asked Questions

What is the difference between folic acid, folate, and 5-MTHF?

Folic acid is the synthetic form of folate used in most supplements and fortified foods. It must be converted by the MTHFR enzyme into the active form 5-methyltetrahydrofolate (5-MTHF) before the body can use it. Many people — up to 40% — carry MTHFR gene variants that reduce this conversion, leading to functional folate deficiency even when folic acid intake appears adequate. Quatrefolic® provides 5-MTHF directly, bypassing this conversion entirely.*

Who should consider taking active folate instead of folic acid?

Anyone with known MTHFR gene variants (particularly C677T or A1298C), those with elevated homocysteine levels, women planning pregnancy who want to ensure optimal folate status regardless of MTHFR status, people with mood or cognitive concerns related to methylation, and those who have not responded well to standard folic acid supplementation.*

Does active folate support mental health?

Folate plays a central role in the methylation cycle, which is essential for synthesising neurotransmitters including serotonin, dopamine, and norepinephrine. Suboptimal methylation due to MTHFR variants or folate insufficiency has been linked to mood imbalances. Using active 5-MTHF ensures the methylation cycle has adequate folate co-factor activity for neurotransmitter production.*

Is Quatrefolic the same as methylfolate?

Yes. Quatrefolic® is a patented form of (6S)-5-methyltetrahydrofolate — the same bioactive methylated folate found in nature and used directly by the body. It differs from other methylfolate ingredients primarily in its glucosamine salt form, which improves stability and solubility. Quatrefolic® has been clinically studied and is one of the most reliable and well-documented 5-MTHF ingredients available.*