St. John's Wort Extract

Why St. John's Wort Is in Memodyne

A well-studied herb for low mood, and the ingredient in this formula with the most serious and wide-ranging drug interactions. It is one of the six named ingredients in the Memodyne formula, and this page covers what it is, the general research context around it, its role here and the cautions attached to it.

What St. John's Wort in Memodyne Is

St. John's wort is Hypericum perforatum, a yellow-flowered plant found across Europe and beyond, named for its flowering around St. John's Day in late June.

Its compounds of interest include hypericin and hyperforin. Hyperforin in particular is the one responsible for most of the drug interactions described below, because it activates enzyme systems in the liver that clear medications from the body.

In several European countries it is regulated as a medicine for mild to moderate depression rather than sold as a supplement, which reflects both its activity and the caution it warrants.

The Research Context Behind St. John's Wort in Memodyne

This is one of the better-evidenced botanicals in the world, and that deserves acknowledgement.

Cochrane reviews of St. John's wort for major depression have found it comparable to standard antidepressants for mild to moderate symptoms, with fewer side effects in the trials examined. That is an unusually strong result for a herbal preparation.

Important context for this product: that research concerns depression, studied at defined daily doses of standardised extract, in people with diagnosed symptoms. It is not research on cognitive enhancement in healthy adults.

The connection to a cognitive formula is indirect but real: low mood measurably affects concentration, motivation and memory, so supporting mood can support cognition. That is a reasonable inference rather than a demonstrated finished-product effect.

Why St. John's Wort Is Included in Memodyne

It carries the formula's mood pathway, on the reasoning that mood and cognitive function are connected.

It is worth being direct about the trade-off this inclusion creates. It brings the best mood evidence available in a botanical, and it also makes the entire product unsuitable for a large number of people — anyone on antidepressants, anticoagulants, hormonal contraception, immunosuppressants, certain heart medications, HIV or cancer treatments, and more besides.

The amount is not published, which matters here as much as anywhere: depression trials used defined doses of standardised extract, and interaction severity relates to hyperforin content.

Safety and Interactions for St. John's Wort in Memodyne

This is the most important section on this entire website.

St. John's wort induces cytochrome P450 enzymes and the P-glycoprotein transporter, which means it speeds up how the body clears a wide range of medicines — and can make them stop working.

Documented interactions include: SSRIs and other antidepressants, where the combination risks serotonin syndrome, a potentially life-threatening condition; oral contraceptives, where reduced effectiveness and breakthrough bleeding are well documented; warfarin and other anticoagulants; immunosuppressants including ciclosporin and tacrolimus, where transplant rejection has been reported; certain HIV antiretrovirals; some cancer treatments; digoxin; and anticonvulsants.

It can also cause photosensitivity — increased sensitivity to sunlight — and should be stopped before surgery.

Do not start this or any St. John's wort product without speaking to your doctor or pharmacist if you take any prescription medication. If you rely on hormonal contraception, this conversation is essential rather than advisable. And do not stop a prescribed antidepressant in order to take a supplement instead.

Related Memodyne Reading

The main ingredients page sets out how all six work together, and how Memodyne works explains the five pathways and their limits in more depth.