How Hormones Influence Your Sense of Smell (2024)

Hormonal changes throughout your menstrual cycle affect your sense of smell. Oestrogen fluctuations enhance or diminish scent perception, impacting even sexual arousal. Progesterone can make us more sensitive to the smell of fatty foods. During the premenstrual week, oestrogen decline makes you scent-sensitive, but calming scents like lavender offer relief.

The Olfactory System: A Quick Overview

Before diving into the world of hormones, let's briefly understand how our sense of smell works. The olfactory system is a complex network of nerves and receptors responsible for detecting and interpreting odours. When we smell something, molecules from the substance travel through the air and interact with specialised olfactory receptors located in the nasal cavity. These receptors send signals to the brain, which then processes the information, allowing us to perceive and identify the smell.

Oestrogen and Olfaction:

The nasal respiratory epithelium (the tissue lining the nasal passages) contains receptors for female hormones, and oestrogen is also important because it nourishes this nasal tissue. Fluctuating levels of oestrogen may therefore affect olfactory ability, potentially making you more easily annoyed or overpowered by scents of any kind, as well as other sensory input, such as loud noises, scratchy textures and unpleasant tastes.

In some cases, smells can stimulate the trigeminal nerve, which sends pain, touch, and temperature sensations to the brain. The trigeminal nerve can become inflamed when smell perceptions are overwhelmed, and this may cause headaches or even migraines.

Some scents (different for each person) can cause blood vessels in the brain to dilate or constrict, resulting in headaches.The connection between smell and taste and female hormones is possibly linked to evolutionary advantages to pregnant women, who benefit from an increased ability to detect and avoid potentially toxic or noxious foods, for instance, the presence of mould or rot. There is also an increase in the perception of the smell around the time of ovulation, which we will discuss in more detail below, which is thought to improve the chances of selecting an appropriate mate.

Change of Smell in Perimenopause:

During perimenopause, the transitional phase leading up to menopause, many women experience a range of physical and physiological changes, and alterations in the sense of smell can be one of them. Hormonal fluctuations are a hallmark of perimenopause, specifically a decline in oestrogen levels. As oestrogen levels decrease, some women may notice changes in their sense of smell. This can manifest as heightened sensitivity to certain odours or, conversely, a diminished ability to detect and distinguish scents. These changes in olfactory perception can vary from person to person and may contribute to some of the sensory changes that women experience during perimenopause.

Testosterone and Olfaction:

Testosterone, the primary male sex hormone, also plays a role in olfaction. While it might not enhance the sense of smell to the same degree as oestrogen in women, it can influence odour perception. Research suggests that men with lower testosterone levels may be less sensitive to certain odours. (1) This could explain why men and women sometimes have different preferences when it comes to fragrances and scents

How your sense of smell changes in each stage of the menstrual cycle

During your period:

At the start of your period week, aka your week 1, your sense of smell starts off at the low end of its scale due to bottomed-out oestrogen. But, as the level of this hormone rises day by day, you can detect more subtleties in aromas and enjoying scents of all sorts. In fact, a study in the journal Psychophysiology shows you have greater sexual arousal when you smell a pleasant fragrance someone is wearing throughout this cycle week.(2) This intriguing finding sheds light on how hormonal changes can even influence your romantic experiences. As oestrogen gradually climbs during week 1, it seems to enhance not only your olfactory perception but also your sensitivity to pleasurable fragrances, adding a unique dimension to your sensory experiences during this phase of your cycle.

Follicular phase and Ovulation:

Your sense of smell peaks from day 8 up until ovulation. Oestrogen rises at this time until it peaks and testosterone also rises and peaks just before ovulation. The closer you get to ovulation, the more oestrogen improves your smelling ability, helping you to detect more subtleties in aromas. For some the increased sensitivity to smell at this time can cause you to be turned off by some scents that you normally don’t find so overpowering.

Luteal phase:

The luteal phase begins the day after ovulation and lasts until you start to bleed again. Progesterone rises throughout the luteal phase, while in the first half of the luteal phase oestrogen and testosterone and in the second half oestrogen rises again.

Interestingly, post-ovulation it seems that we have an increased sensitivity to a more specific smell, that of high-fat foods! According to researchers at University of Ottawa, we get better at determining the source of aromas of foods high in fat during this phase of our cycle–and this is likely one culprit behind increased cravings for fatty foods on these days. (3)

This is likely due to rising progesterone levels and could be one of the various ways this hormone pushes you to consume more calorie-dense food in case you got pregnant during ovulation and need to nourish your body more as you grow a baby. This unique olfactory phenomenon highlights the intricate ways in which your hormones influence not just your sense of smell but also your dietary preferences during different phases of your menstrual cycle.

You can become more even more scent-sensitive in the final week of your cycle as oestrogen and progesterone plunge and PMS symptoms often show their face.

Plummeting oestrogen levels can make you more easily annoyed or overpowered by scents of any kind–even those you normally enjoy during other cycle weeks. That’s because as oestrogen drops, it makes you more sensitive to sensory input of all kinds.