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Can I take Oestrogel pump-pack and Vitamin C together?

Drug interaction guide

Taking high doses of Vitamin C (ascorbic acid) alongside Oestrogel can increase the levels of oestrogen in your bloodstream. This might increase the risk of oestrogen-related side effects, such as breast tenderness, bloating, or nausea. Conversely, if you suddenly stop taking Vitamin C after your body has adjusted to the combination, your oestrogen levels could drop, potentially causing a return of menopause symptoms.

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Why this happens

Both Vitamin C and oestrogen (estradiol) compete for the same 'breakdown' process in the body (specifically a process called sulfation). Because the Vitamin C keeps the breakdown enzymes busy, less oestrogen is cleared from your system, leading to higher levels in the blood.

You do not need to avoid Vitamin C, but you should avoid taking very high doses (over 1,000mg per day) of Vitamin C supplements. If you are already taking a Vitamin C supplement, try to be consistent with your daily dose rather than starting and stopping it abruptly. If you notice increased breast pain or other side effects, speak to your doctor.

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Blood clots and breast cancer

You must not use Oestrogel if you have ever had breast cancer, or if you have ever had a blood clot in a vein (thrombosis) or the lungs (pulmonary embolism).

Oestrogel slightly increases your risk of blood clots (DVT/PE), stroke, and breast cancer. Seek immediate medical help if you experience sudden chest pain, breathlessness, or painful swelling in one leg.

Unexplained vaginal bleeding

Do not use Oestrogel if you have any vaginal bleeding that has not been checked and explained by your doctor.

Skin contact transfer

Do not allow other people, especially children, to come into contact with the area of skin where you applied the Oestrogel. Cover the area with clothing once dry to prevent accidental hormone transfer.

Kidney stones (renal calculi)

High doses of vitamin C can increase the amount of oxalate in your urine, which significantly raises the risk of developing kidney stones, especially if you have had them before.

G6PD deficiency

Very high doses of vitamin C can cause oxidative stress and lead to the breakdown of red blood cells (haemolysis) in individuals with G6PD deficiency.

Alcohol

It is best to avoid or strictly limit alcohol while using these treatments. Alcohol can increase oestrogen levels in the body, potentially increasing the risk of side effects. Additionally, regular alcohol consumption can deplete your body's levels of Vitamin C.

Grapefruit juice

Grapefruit juice can interfere with how your body breaks down estradiol. This can lead to higher levels of the medicine in your bloodstream, potentially increasing the risk of side effects such as breast tenderness, nausea, or headaches.

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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.

  • 25 Jan 2026 | Originally published
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