What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
Can you take berberine and St John’s wort together?
Nobody has tested this pair.
As of August 2026, no human trial has given berberine and St John’s wort together. We searched PubMed for trials naming both on 26 August 2026 and read every candidate it returned; none tested the pair.
8 studies · none tested the actual pair · 2 cautions
See what each one is on its own
What you’re seeing
- Berberine renders solid: for blood sugar, it is well studied and it works.
- St John’s wort renders half-there: for mood, the science is still forming.
- Nothing is drawn between them, because nothing has been run. The empty space is the review.
- The red spark: St Johns wort speeds up how the liver clears many prescription medicines. A controlled study measured a roughly 140 percent increase in CYP3A4 activity, the enzyme that processes a large share of common drugs. That can make the contraceptive pill, blood thinners, transplant medicines, HIV medicines and some antidepressants stop working properly. Do not take it alongside prescription medication without asking your doctor or pharmacist first.
You can tell before you read a word.
Vitamin D + vitamin K2 is what the other answer looks like. Someone ran the study, so a cord is drawn between them. That is the whole difference.
Fair questions
Is it safe to take berberine and St John’s wort together?+
No trial has tested the combination, so there is no evidence either way. Nobody has found a problem, and nobody has looked.
Why does this page say nobody has tested it?+
Because we ran the search and read the results. The date above is the day we ran it. We do not claim a pair is untested without a logged search behind it.
Will this page change?+
Yes, if a trial publishes. We re-run these searches and the page changes from air to a cord the day the evidence does.
Deeper
The search we ran+
On 26 August 2026 we asked PubMed for trials, reviews and meta-analyses naming both berberine and St John’s wort. It returned 1 candidate. We read every one and none gave the two together. This page carries a date because the answer can change: if a trial publishes, the air becomes a cord.
What each one is on its own+
Berberine
- Blood sugarsolid
- Cholesterolsolid
- Colorectal polypssolid
- Inflammationhalf-there
- Weight and body fathalf-there
St John’s wort
- Moodhalf-there
Pairs that have been tested+
- Berberine has been tested with probiotics, milk thistle.
- St John’s wort has been tested with chromium, kava.
These are the combinations someone has actually run a study on. Every other pairing here is air.
Worth knowing+
- St Johns wort speeds up how the liver clears many prescription medicines. A controlled study measured a roughly 140 percent increase in CYP3A4 activity, the enzyme that processes a large share of common drugs. That can make the contraceptive pill, blood thinners, transplant medicines, HIV medicines and some antidepressants stop working properly. Do not take it alongside prescription medication without asking your doctor or pharmacist first.
- Berberine commonly upsets the stomach. Across 12 trials that reported side effects, digestive complaints such as constipation, diarrhoea and nausea were more frequent on berberine than on placebo (2 to 23 percent versus 2 to 15 percent). No serious adverse events were reported.