The Science of… Period Cramps
- Laura Feather
- Sep 28
- 3 min read
September can feel a bit like the luteal phase of the year: the light is fading, energy dips, and there’s a sense of tension before the reset of autumn properly begins. Just like in a woman’s menstrual cycle, it’s a time when the body and mind feel more sensitive, more reactive, and sometimes, downright uncomfortable. And if there’s one thing that captures that mix of pressure, fatigue, and unpredictability, it’s period cramps.
Whether you experience them yourself or know someone who does, period cramps - aka dysmenorrhea - are a monthly reality for millions. But here’s the big question: why do some people breeze through their periods while others feel like their uterus is trying to fold-in on itself?
Turns out, science has the answers...
What are period cramps, anyway?
The uterus is a muscle, and during menstruation, it contracts to shed its lining. These contractions are triggered by hormone-like substances called prostaglandins, the real instigators of the pain.
Prostaglandins are chemical messengers that play a big role in inflammation and pain. During your period, levels of prostaglandin rise, causing the uterus to contract more forcefully. If those levels get too high, the contractions can squeeze blood vessels so tightly that oxygen can’t reach the tissue, which is what causes the pain.
Some people naturally produce more prostaglandins than others, which is why cramping can range from manageable to debilitating.
But cramps don’t just stay in the uterus. They can radiate to your lower back, thighs, and even cause nausea, diarrhoea, or headaches. That’s because prostaglandins affect other smooth muscles in the body too.
So when you put the whole thing together, during period cramps you experience your:
Nerve endingsin the uterus responding to the intense contractions.
Reduced blood flow causing ischaemic pain (pain from lack of oxygen).
Other muscles getting involved, leading to digestive issues and headaches.
What you eat matters...
What you eat can also impact prostaglandin levels. A diet high in omega-6 fatty acids (the inflammatory fatty acids) such as vegetable oils and walnuts, can increase prostaglandin levels. However balancing this with omega-3 fatty acids (the anti-inflammatory acids), such as salmon and mackerel, can help to reduce prostaglandin levels, thus reducing period pain!
Nutritional deficiencies can make cramps worse, sometimes by influencing prostaglandin levels, but also by affecting levels of inflammation.
Calcium helps muscles contract and relax properly. Low levels = more spasms.
Vitamin D regulates prostaglandin production. Less D = more pain.
Zinc is anti-inflammatory. A deficiency can mean more inflammation and discomfort.
So you can get part way to taking control of your period pain by controlling your diet!
The oestrogen effect...
Oestrogen, the hormone that regulates your menstrual cycle, also affects prostaglandin production and sensitivity. Higher oestrogen levels can lead to more prostaglandins and more pain.
Science helps us understand period cramps, but can it also help us feel better?
Once you understand what’s going on, you can take steps to manage it:
NSAIDs (like ibuprofen) block prostaglandin production.
Hormonal birth control can reduce the uterine lining and prostaglandin levels.
Heat therapy boosts blood flow and relaxes muscles.
Exercise releases endorphins - your body’s natural painkillers.
Diet - decreasing omega-6 fatty acid consumption and increasing omega-3 fatty acid consumption can decrease prostaglandin production.
Period cramps aren’t just a monthly inconvenience, they are a complex mix of hormones, muscle activity, nutrition, and even stress. But the more we understand the science, the better we can manage the pain and support each other through it.
Let us know what you think in the comments or on socials @LitLabLondon
Sources:
Abdi, F., Amjadi, M.A., Zaheri, F. and Rahnemaei, F.A. (2021). Role of vitamin D and calcium in the relief of primary dysmenorrhea: a systematic review. Obstetrics & Gynecology Science, 64(1), pp.13–26. doi:https://doi.org/10.5468/ogs.20205.
Dr. Jolene Brighten (2018). How Prostaglandins Cause Painful Periods + What to Do About It. Dr. Jolene Brighten. Available at: https://drbrighten.com/how-prostaglandins-cause-painful-periods-what-to-do-about-it/.
NHS (2023). Facts about Fat. NHS. Available at: https://www.nhs.uk/live-well/eat-well/food-types/different-fats-nutrition/.
Sullivan, T. (2025). 6 ways to ease PCOS period pain | Fertility Family. Fertility Family. Available at: https://www.fertilityfamily.co.uk/blog/pcos/6-ways-to-ease-pcos-period-pain/
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