Folic acid and 5-MTHF are not the same thing

Pick up two folate supplements. One says folic acid, the other says 5-MTHF. Both will be filed under folate on the label, and plenty of shops treat the two words as interchangeable. They are not the same molecule.

Folate is the umbrella term. Folic acid is a synthetic form of it, stable and cheap, which is why it has been the default in supplements and fortified food for decades. 5-MTHF, written in full as 5-methyltetrahydrofolate and often sold as L-methylfolate, is the form that circulates in the body already.

The conversion step

Folic acid is not used in the form you swallow it. The body works it through a short chain of steps to reach 5-MTHF, and the last of those steps is run by an enzyme called MTHFR. 5-MTHF skips that chain because it is already at the end of it.

How efficiently any given person runs that conversion varies, and there are common variations in the gene that codes for the enzyme. That is the whole reason the methylated forms exist as a product category.

What we are not going to tell you

This is where most writing on the subject goes off the rails, so we will be plain about it. We are not telling you folic acid does not work. It is one of the most studied supplement ingredients there is, and for most people it does the job perfectly well.

We are not telling you to read a gene test result and change what you take on the strength of it. Interpreting one is a conversation with a healthcare professional, not something to settle from a product page. And if you are pregnant or trying to be, folate is firmly a question for your midwife or GP. We are not going to give you advice on it and you should be wary of any shop that does.

What we will say is that if you already know you would rather take the active form, the label should tell you plainly which one you are getting.

Reading the panel

Two things worth checking. The first is which form it actually is: folic acid and 5-MTHF are different entries, and a panel that only says folate is not telling you enough. The second is the number. Folate is sometimes stated as dietary folate equivalents rather than the weight of the ingredient, and the two figures are not comparable, so a bigger number is not automatically more.

Ask what the form is and ask what the milligram or microgram figure refers to. If both are printed, you can compare products honestly.

For what it is worth, ours is 800mcg of 5-MTHF, as L-methylfolate, in a methylated B-complex alongside methylcobalamin, active B6 and B2. It is on the panel because a number you can check is worth more than a form you cannot.