Can I take Magnesium and Oestrogen tablets together?

Why this happens

There are no significant pharmacokinetic interactions (how the body absorbs or breaks down the drugs). From a pharmacodynamic perspective, oestrogen can lower magnesium levels in the blood by shifting the mineral into the bones or increasing its loss through urine. Conversely, magnesium may help support the liver in processing oestrogen and can help reduce some oestrogen-related side effects like fluid retention or leg cramps.

What you should do

You can take these two together. It is often best to take magnesium at a different time of day (for example, in the evening) if you find it helps with sleep or muscle relaxation. If you are taking oestrogen as part of HRT, ensure you are getting enough magnesium through your diet or supplements, as oestrogen can sometimes lower your magnesium levels. Always inform your doctor or pharmacist about all supplements you are taking.

Important precautions

Blood clots and breast cancer

Oestrogen can increase your risk of developing blood clots (DVT or pulmonary embolism) and breast cancer. Seek immediate medical help if you experience sudden leg swelling, chest pain, or breathlessness.

Breast Cancer

Long-term use of oestrogen (especially when combined with progestogen) is associated with an increased risk of breast cancer. You should perform regular breast self-examinations and attend scheduled mammograms.

Kidney disease

If you have severe kidney problems, your body may not be able to remove excess magnesium, leading to dangerously high levels in the blood. Check with your doctor before use.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking oestrogen. Alcohol can increase the levels of oestrogen in your body, which may increase the risk of side effects. Additionally, long-term alcohol consumption combined with HRT may further increase the risk of breast cancer.

It is best to avoid or strictly limit alcohol when taking magnesium. Alcohol acts as a diuretic, which can increase the amount of magnesium your body loses through urine, potentially making the supplement less effective. Additionally, chronic alcohol use can lead to magnesium deficiency.

Grapefruit and grapefruit juice

Grapefruit can increase the levels of oestrogen in your blood by slowing down how your body breaks it down. This may increase the risk of side effects such as breast tenderness, nausea, or headaches. It is best to avoid large amounts of grapefruit products while taking this medicine.

Dairy products (Milk, Cheese, Yoghurt)

Avoid taking magnesium supplements at the same time as large amounts of dairy products. Dairy is high in calcium, and high doses of calcium can compete with magnesium for absorption in the gut, meaning you may not get the full benefit of your supplement. It is best to space them at least 2 hours apart.

Caffeine (Coffee, Tea, Energy drinks)

It is best to limit caffeine intake around the time you take magnesium. Like alcohol, caffeine has a mild diuretic effect and can increase the excretion of magnesium through the kidneys.

Oestrogen can slow down the rate at which your body processes caffeine. This may make you feel more sensitive to the effects of caffeine, leading to jitteriness, heart palpitations, or difficulty sleeping.

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.