Reproductive hormones: We’re not all the same

Senior Kinsey researcher Dr. Virginia Vitzthum recently visited Clue to speak about her research on hormonal profiles. She gave us some insight on how hormone levels differ from region to region. Hormonal profiles, it turns out, tend to vary more cross-culturally, than they do between people within the same population. A lot more research on these variations is needed — research will advance our understanding of female health, and help us to develop new contraceptive technologies. It will also allow us to improve upon existing forms of hormonal contraception, which are generally produced to fit a globally narrow hormonal “norm”.

What is a hormonal profile?

A reproductive hormonal profile outlines the amount of each reproductive hormone you have and how they are balanced in relation to one another.

The primary hormones involved in the menstrual cycle are estrogen (specifically estradiol) and progesterone. Other reproductive hormones include luteinizing hormone, follicle stimulating hormone, gonadotropin-releasing hormone, prolactin and testosterone. During the reproductive years, these hormones are mainly produced in the ovaries and in the brain. The menstrual cycle functions because of the production, timing and levels of these hormones.

What do they do?

A lot. Estrogen and progesterone are important for reproduction, but they play a key role in other bodily functions as well. Sleep, mood, bone formation and heart health are all affected by levels of estrogen, for example. The equilibrium of reproductive hormones is important for overall health.

In a way, the hormones in the menstrual cycle act a bit like they are in relay race. As the cycle moves forward, one hormone often triggers the next, which then triggers the next, moving the cycle through its different phases (menstruation, follicular, ovulation, luteal).

Too much or too little of certain hormones can stop the cycle from functioning as it should. If one hormone doesn’t “pass the baton”, things can slow down or stop altogether. Too much of one hormone can lead it to pass the baton too fast, before the next runner is ready. It’s a delicate, and important, balance.

Are hormonal profiles all the same?

While we have general ideas of what “normal” ranges are, these ranges change from population to population. Different factors like how a culture eats and typical lifestyles can affect how an average hormonal profile looks. Dr. Vitzthum’s recent research in rural Bolivia showed hormonal levels that were significantly lower overall than people in the United States. Her other research comparing east and west Germany found that average hormonal profiles differed depending on what side of the wall a person was from.

Hormonal profiles also differ between individuals within a population, like in people of different weights, but overall these variations are less significant than the difference across cultures.

How does this affect your life?

Your individual hormonal profile affects you when it’s out of balance. Your population’s average profile affects you if you are choosing to use hormonal birth control (HBC).

HBC is typically designed for one particular hormonal average — those of average build, of European descent, living in the industrialized west.

If you live somewhere with good access to healthcare, and your HBC isn’t working for you, you will luckily have a lot of options. You’ll be able to adjust a dosage, or try a different brand if you develop any unpleasant symptoms. It’s normal to have to try a few different combinations before finding one that suits you (people can spend years on a HBC that doesn’t suit them). Unfortunately, not all people or populations have this option. And taking HBC that wasn’t designed for your population’s average hormonal profile can create symptoms that interfere with daily life.

Looking forward

This is why cycle research is so important. Learning more about different hormonal profiles will allow companies to make contraception that is better suited to the variations in different demographics. We will stop asking people to fit to the drug — and start better fitting the drug to different groups of people.

Getting profiled

If you’re having trouble with your cycle, you and your doctor might consider checking your hormonal profile. Typically you’ll be asked what day of your cycle you’re on, how long your average cycle lasts (bring your smartphone!), and you’ll receive a blood test. You’ll learn if your hormones are in balance for that day of the cycle. If they’re not, you’ll be on the right track for making adjustments or getting further treatment.

Keep in mind that most cycles fluctuate, and few cycles are completely regular. But if your cycles are clinically irregular, or you’re having concerning symptoms, something more might be going on. Testing your hormonal levels can give you important insight on what next steps to take.