Can I take Black cohosh and Magnesium together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
- Audio Version
- Add to preferred sources on Google
There are no known significant interactions between black cohosh and magnesium supplements. They are generally considered safe to take together.
Why this happens
Black cohosh and magnesium are processed by the body through different pathways. Black cohosh is primarily broken down by the liver, while magnesium is an essential mineral absorbed in the intestines and filtered by the kidneys. They do not interfere with each other's absorption or effectiveness.
What you should do
You can safely take these two supplements together. However, always follow the dosage instructions on the product labels. If you have pre-existing liver conditions (relevant to black cohosh) or kidney issues (relevant to magnesium), it is best to consult your GP or a pharmacist before starting new supplements.
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.
Kidney disease
If you have reduced kidney function, your body cannot clear magnesium properly. This can lead to dangerously high levels in the blood, which can cause heart rhythm problems and muscle weakness.
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.
Dairy products (Milk, Cheese, Yoghurt)
Dairy products are high in calcium. Taking large amounts of calcium at the same time as magnesium supplements can interfere with how well your body absorbs the magnesium. It is best to space them out by at least 2 hours.
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.
Patient picks for Drug interactions

Drug interactions checker
Can I take Mounjaro and Insulin together?
Taking Mounjaro (tirzepatide) and insulin together significantly increases your risk of having a 'hypo' (hypoglycaemia), which is when your blood sugar levels drop too low. Symptoms of a hypo can include feeling shaky, sweaty, dizzy, hungry, or confused. In severe cases, it can be dangerous.

Drug interactions checker
Can I take Sertraline and Fluoxetine together?
Taking sertraline and fluoxetine together significantly increases the risk of a rare but serious condition called serotonin syndrome. This happens because both medicines work by increasing the level of a chemical called serotonin in your brain. If levels get too high, it can cause symptoms like shivering, diarrhoea, confusion, severe muscle tightness, fever, and even seizures. Additionally, fluoxetine can slow down how your body breaks down sertraline, leading to a build-up of the drug in your system and increasing the risk of side effects.
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
Join the conversation
Share your thoughts or experiences with others in our patient communities.

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.
More in drug interactions checker
- Can I take Adcal-D3 and Collagen together?
- Can I take Amlodipine and Danazol together?
- Can I take Apixaban and Fibre supplements together?
- Can I take Atorvastatin and Levothyroxine together?
- Can I take Atorvastatin and Pyridostigmine together?
- Can I take Black cohosh and Vitamin C together?
- Can I take Calcium and Esomeprazole together?
- Can I take Ciprofloxacin and Dairy together?
- Can I take Codeine and Morphine together?
- Can I take Empagliflozin and Rybelsus together?
- Can I take Esomeprazole and Indapamide together?
- Can I take Evening primrose oil and Vitamin C together?
- Can I take Fexofenadine and Pregabalin together?
- Can I take Fluanxol and Iron supplements together?
- Can I take Pregabalin and Sertraline together?
- Can I take Sedoxil and Vitamin D together?
- Can I take Sertraline and Paracetamol together?
- Can I take Solifenacin and St John's wort together?
- Can I take Solifenacin and Vitamin B12 together?
- Can I take Tetracycline and Calcium together?