Immune System - constantly picking up infections since finishing my breast cancer treatment. What can I do to improve it?

Hi I had chemotherapy and radiotherapy back in 2021 for breast cancer plus 3 lymph nodes had cancer so all removed.

My Oncologist put me on a cancer treatment drug, Exemestane which I stopped in November 2025 due to side effects.

My problem is I struggle with fatigue and constantly pick up infections, the latest lasting from 7th January 2026. 

I have been taking Moringa herbal tablets to boost my immune system but they don’t seem to be effective.

Has anyone experienced these symptoms and if so is there anything I can take to help my immune system? 

I try to attend the gym doing weights but then I take ill, it is very frustrating.

I am on a tablet to help my bones which I take once a week.

Thank you

  • Hello Oct and thank you for posting.

    I’m really sorry to hear about everything you’ve been dealing with. Going through treatment for breast cancer is tough enough on its own, so continuing to feel exhausted and repeatedly picking up infections afterwards must be incredibly frustrating.

    Fatigue is a very common effect of cancer treatment, and for some people it can last for many months, sometimes longer, after treatment has finished. Most people do find that it gradually improves over time. Macmillan Cancer Support has some helpful information about managing fatigue and life after treatment, which you may find useful.

    If it hasn’t already been done, it would be worth asking your GP for a blood test. This can check for things like anaemia or vitamin D deficiency, which can contribute to tiredness and low immunity and may be simple to treat.

    Although we know that a healthy, balanced diet supports the immune system, there isn’t strong scientific evidence that specific supplements make a difference for most people. Alongside eating well, some people find that maintaining a regular sleep routine, doing gentle or moderate exercise, and managing stress (as much as possible) can also help with energy levels and overall well-being.

    I hope this is helpful, but please do get back in touch if you have more questions. If you’d prefer to speak to a nurse, we’re here Monday to Friday, 9am–5pm on our free helpline: 0808 800 4040.

    Take care,

    Jemma

  • Thank you Jemma I will have a look at the links provided plus my eating habits.