Can I take Black cohosh and Vitamin B2 together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
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There are no known significant interactions between black cohosh and vitamin B2 (riboflavin). It is generally considered safe to take these two supplements together.
Why this happens
Black cohosh and vitamin B2 are processed by the body through different pathways. Vitamin B2 is a water-soluble vitamin that is absorbed in the small intestine and excreted through urine. Black cohosh is metabolised primarily by the liver. There is no evidence that they interfere with each other's absorption, metabolism, or effectiveness.
What you should do
You can continue to take both supplements as directed. However, always inform your doctor or pharmacist about all supplements you are taking, especially if you have a history of liver problems, as black cohosh has been rarely linked to liver issues.
Important precautions
Pregnancy
Do not use black cohosh during pregnancy. It may stimulate uterine contractions, potentially increasing the risk of miscarriage or premature labour.
Liver disease
Black cohosh has been linked to rare but serious cases of liver failure. You must stop taking it and see a doctor immediately if you develop yellowing of the skin or eyes, dark urine, or severe stomach pain.
Hormone-sensitive conditions (e.g. breast cancer)
Because black cohosh may act like the hormone oestrogen, you should not use it if you have a history of breast cancer, uterine cancer, or endometriosis without specialist medical supervision.
Food and drink warnings
Alcohol
Black cohosh has been linked to rare but serious cases of liver damage. Because alcohol also puts strain on the liver, it is advisable to limit or avoid alcohol consumption while taking this supplement to reduce the risk of liver toxicity.
Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
Article also available in English, German, Spanish, French, Italian, Portuguese, Hindi, Hebrew, Arabic, and Swedish.
25 Jan 2026 | Originally published
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