Endocrinology is the study of hormones, which are essential for health and wellbeing. Hormones are biological messengers that travel throughout the body, telling cells and tissues what to do. When they are out of balance or fail, this can lead to the development of prevalent chronic diseases such as diabetes, thyroid disorders, cancer, osteoporosis and obesity, and other health challenges such as infertility. There are also more than 440 rare endocrine conditions that affect millions of people, but often go undetected.
To learn more about endocrinology and the endocrine system, watch the animation (left), shared as part of ESE's World Hormone Day campaign.
Despite scientific progress and increased awareness in some areas, there’s still a lot more that can be done. To raise awareness about the importance of good hormone health and help the endocrine community share and support each other’s activities, we encourage everyone to use the hashtag #BecauseHormonesMatter on social media and on endocrine-related awareness days.
The Because Hormones Matter awareness days calendar includes many European and worldwide initiatives that we can all support (perhaps your organisation has one, too).
Download the calendar and check out our online awareness days diary
See Awareness Days Calendar and Online Diary
Follow us on Instagram, where we share public-facing information about hormone health and celebrate the fantastic work of the endocrine community
Follow @BecauseHormonesMatter on Instagram
From European Hormone Day to World Hormone Day
European Hormone Day began in 2022 to bring together the endocrine community and put the spotlight on endocrine health. The aim was to issue a collective call for change about how hormones and endocrine-related disease are addressed in public policy across Europe.
Over the years, the campaign has grown from a European initiative into a global initiative to raise awareness and promote better hormone health:
- In 2022, ESE and the ESE Foundation published “Recognising the key role of hormones in European health: the Milano Declaration,” calling for stronger emphasis on endocrine perspectives in European health policies. To date, 35 national and specialist societies have endorsed the Milano Declaration.
- In 2023, the focus was on "10 Recommendations for Good Hormone Health" with simple actions each of us can take to ensure better hormone health. We also published Because Hormones Matter: Working together to raise awareness and promote better endocrine health in Europe, which included a calendar to help the endocrine community focus our combined efforts over the coming year. The updated calendar is available to download here.
- In 2024, the campaign reached over 40 million people through social and news media. Watch the 2024 highlights video to see how participants marked the day.
- In 2025, we marked the first ever World Hormone Day, taking the message worldwide and reaching an estimated audience of more than 136 million people worldwide, with activities in 40 countries. You can watch the 2025 highlights video here.
On 24 April 2026, the global endocrine community joined forces to help spread the word around the world about why hormones matter and the small steps we can all take towards better hormone health – #BecauseHormonesMatter
Thank you to everyone who took part and helped make the day a success!
