A complete safety, timing, and dosage guide for combining St. John's Wort with Vitamin B12 (Cobalamin, Methylcobalamin) — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can safely combine vitamin B12 and St. John's Wort because they do not interact in any clinically meaningful way.
Vitamin B12 and St. John's Wort together are safe and do not affect each other's absorption or activity. St. John's Wort may alter liver enzymes, but vitamin B12 bypasses these pathways. You can take them as part of your daily routine without concern.
Vitamin B12 is a water-soluble vitamin absorbed in the terminal ileum via intrinsic factor, and it acts as a coenzyme in DNA synthesis and methylation. St. John's Wort, on the other hand, is a plant extract that induces hepatic cytochrome P450 enzymes (notably CYP3A4) and P-glycoprotein, which can reduce blood levels of many drugs. However, B12 is not significantly metabolized by these enzymes nor is it a substrate for P-glycoprotein, so St. John's Wort does not alter B12 status. The two nutrients do not share absorption transporters or enzymatic pathways, so there is no biological mechanism for an interaction. In sum, the lack of pharmacokinetic overlap explains why this combination is neutral.
If you need both supplements, take them together in the morning with breakfast to build a consistent routine. For vitamin B12, swallow a methylcobalamin tablet or use a sublingual form; it absorbs fine on an empty stomach, but food can help. St. John's Wort is best divided into two or three doses throughout the day, but if you take it once daily, morning is preferred. There is no need to space the two supplements apart — they can be taken simultaneously. If you have pernicious anemia or intestinal malabsorption, continue B12 injections as prescribed, as St. John's Wort will not interfere.
The form of vitamin B12 (methylcobalamin vs. cyanocobalamin) and St. John's Wort (standardized to hypericin vs. hyperforin) does not change the neutral interaction. Methylcobalamin is a more bioavailable coenzyme form, but it follows the same absorption route as cyanocobalamin and is equally unaffected by St. John's Wort. Sublingual or injectable B12 also avoids intestinal absorption, but still no interaction exists. Thus, you can use any widely available form of each supplement without worry.
Vitamin B12 is frequently combined with other B vitamins in B-complex formulations, while St. John's Wort is usually sold standalone or with other botanical extracts like lemon balm. These two supplements are not commonly stacked together in commercial products, but they are safe to self-combine.
Yes, you can take vitamin B12 and St. John's Wort at the same time because there is no known interaction between them. I often recommend taking them together with your morning meal to keep it simple. There is no need to separate them.
Yes, it is safe to combine vitamin B12 and St. John's Wort every day. Vitamin B12 is water-soluble and well-tolerated, and St. John's Wort has not been shown to affect B12 levels. Just be aware that St. John's Wort has many drug interactions, so confirm with your pharmacist if you take other medications.
You do not need to wait at all between vitamin B12 and St. John's Wort. I tell my clients to take them at the same time, as timing makes no difference for this pair.
No, they do not compete for absorption. Vitamin B12 is absorbed in the ileum through intrinsic factor, while the active compounds in St. John's Wort are absorbed in the small intestine by different mechanisms. I am not aware of any shared transporter that would cause competition.
While the combination is safe for most people, those who are pregnant or breastfeeding should avoid St. John's Wort altogether. Also, if you take antidepressants, hormonal birth control, or blood thinners, you should not take St. John's Wort without medical supervision because it can make them less effective.
You can take either one with or without food, but taking them with a meal reduces stomach upset if you are sensitive. I suggest taking them with breakfast since St. John's Wort can be stimulating for some people. Vitamin B12 absorbs well with or without food.
Reviewed by Caroline M. on April 8, 2026 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.
The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.