Fibroids & Hormones - Our Hormones do More Than Control Our Cycle

Hormones keep us healthy, happy and fertile.

We have many hormones and the main two that are in charge of our menstrual cycle are Oestrogen and Progesterone. They change each month to control our menstrual cycle, rising and falling depending on the time of the month.

Oestrogen is the hormone in charge of ovulation and the release of an egg each month to  become pregnant.

Progesterone prepares the womb for the pregnancy and takes over if a pregnancy happens.

There hormones don't just have an affect on our womb and ovaries though, they can influence our mood, our energy, sex drive, interests and health.

When oestrogen is high this is when we often feel confident, energetic, and slightly more 'in the mood'.

When progesterone is high, this is the Mother Nature hormone that wants us to settle, stay relaxed incase we are pregnant. This is when sofa days and chocolate seem appealing and it is harder to get out the bed on a morning.

When your hormone levels are changing, you may feel anxious. 

Hormones and Fibroids

Oestrogen drives the growth of fibroids, which is often why they shrink naturally when women enter menopause.

For this reason, a lot of medical approaches to managing fibroids are aimed at lowering oestrogen levels, to shrink the fibroids. This can be really effective, but not ideal if becoming pregnant is your current priority.

The other important thing about this is that when hormone-based medications are given, these naturally influence more than just the fibroids and our cycles. The period we have when on the contraceptive pill is not a 'true period' (because no ovulation has happened).

Some women can be quite sensitive to hormonal treatments, and so it can take time and be a case of trying different types to find one that is most suitable.

We recommend tracking your mood and symptoms across your cycle, this will indicate if you are sensitive to oestrogen or progesterone dropping, and can better inform which type of contraption is right for you. 

Try our symptom tracker here.

Medical disclaimer - This information is for education only and is not a diagnosis or medical advice. Heavy bleeding, long periods, bleeding in between periods, or non-stop bleeding should always be checked by a GP or healthcare professional. They can arrange scans or tests to find the cause and discuss the right treatment options for you.

Author, Dr Liz Murray June 2026

References:

• Murray, L. Not Just Painful Periods, 2026, Octopus Publishing
•  NICE Guidelines Online, National Institute for Health and Care Excellence, April 2023, Health Topics A to Z > Fibroids, https://cks.nice.org.uk/topics/fibroids/ (Accessed online, 2026)
• BNF, https://bnf.nice.org.uk/drugs/linzagolix/ (accessed online, 2026)
•  National Institute for Health and Care Excellence (2018) Dysmenorrhoea: ClinicalKnowledge Summary 2014
• National Institute for Health and Care Excellence (2018) Heavy menstrual bleeding:assessment and management
• Hill, S. How The Pill Changes Everything  2019, Penguin Random House
• Gildersleeve K, Haselton MG, Fales MR. Do women’s mate preferences change across the ovulatory cycle? A meta-analyticreview. Psychol Bull . 2014 Sep;140(5): 1205-59.doi:10.1037/a0035438. Epub 2014 Feb 24. PMID: 24564172.