Can I take Collagen and Tamoxifen together?

Why this happens

Collagen is broken down into amino acids in the digestive tract, similar to eating protein-rich food. It does not interfere with the liver enzymes (such as CYP2D6) that tamoxifen relies on to work, nor does it have known oestrogen-like effects that would interfere with tamoxifen's purpose.

What you should do

You can safely take collagen supplements with tamoxifen. However, always choose high-quality supplements from reputable brands to ensure there are no hidden additives or contaminants. If you have any concerns about new supplements, it is always a good idea to mention them to your oncology team.

Important precautions

Pregnancy and contraception

You must not become pregnant while taking tamoxifen and for nine months after stopping. It can cause serious harm to an unborn baby. Use non-hormonal contraception (such as condoms) as tamoxifen can make hormonal contraceptives like 'the pill' less effective.

Blood clots (Thrombosis)

Tamoxifen significantly increases your risk of blood clots. Seek immediate medical help if you experience sudden shortness of breath, chest pain, or painful swelling in one leg.

Endometrial changes

Tamoxifen can increase the risk of changes to the lining of the womb, including cancer. You must report any unusual vaginal bleeding or changes in your menstrual cycle to your doctor immediately.

Fish, shellfish, or egg allergies

Many collagen supplements are derived from marine or avian sources. Check the label carefully, as these can trigger severe allergic reactions in people with existing food allergies.

Food and drink warnings

Grapefruit and grapefruit juice

Grapefruit can interfere with how your body processes tamoxifen, potentially making the medicine less effective. It is best to avoid grapefruit products while taking this medication.

Alcohol

It is best to avoid or strictly limit alcohol while taking tamoxifen. Both alcohol and tamoxifen are processed by the liver, and combining them may increase the risk of liver-related side effects. Additionally, alcohol can worsen menopausal symptoms like hot flushes, which are common side effects of tamoxifen.

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.