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The effect pregnancy has on your sense of taste is well known (pickles and ice cream, anyone?), but the effect it can have on your sense of smell is less commonly discussed—and just as real. I learned the hard way about those changes to the olfactory system during pregnancy. As a beauty editor, I own an expansive fragrance wardrobe, and every single scent made me sick during my first trimester. Even my favorite fragrance, Matiere Premiere’s Vanilla Powder, made my stomach turn. I knew pregnancy, with all of its hormonal fluctuations, would bring an onslaught of uncomfortable symptoms, but I didn’t expect any of them to totally rewire my nose.
Turns out, I wasn’t alone in this experience. Anate Brauer, MD, a board-certified reproductive endocrinologist, says the change in how I perceived smells during this time is in line with what other patients experience. Being pregnant isn’t the only time this shift can happen, either; any subtle hormonal fluctuations you experience—across your menstrual cycle, during perimenopause, and while using hormonal contraception—can influence how you perceive scent.
Ahead, experts break down how different hormonal shifts and phases in a woman’s life can impact the sense of smell.
Pregnancy
Brought on by hormonal shifts in pregnancy, changes in how you perceive smell “commonly happen in the first trimester,” says Dr. Brauer, adding that patients typically complain about a heightened sense of smell. There’s an evolutionary explanation, she explains: “When you're pregnant, your body goes on high alert to protect you and your baby.” For some, that means nausea triggered by everyday smells; for others, this biological reaction means that long-standing fragrance preferences shift overnight.
There’s also an endocrinological explanation in that the biggest hormonal surge during pregnancy happens during these early weeks. Human chorionic gonadotropin (hCG)—the main pregnancy hormone responsible for fetal development—peaks at about 8 to 11 weeks of gestation. This major hormone shift can shock multiple systems in your body, including the olfactory system. But hCG isn’t the only hormone responsible, estrogen and progesterone also come into play.
Estrogen
The endocrine system is more intertwined with your sense of smell than most people realize, and estrogen is the primary hormone to blame if yours shifts significantly, says Dr. Brauer. Estrogen, which is vital to regulating the female reproductive system, fluctuates during pregnancy, puberty, throughout the menstrual cycle, and menopause. It’s the hormone responsible for the development of breasts during puberty, uterine-lining growth, and the formation of fallopian tubes. “There are estrogen receptors throughout the entire central nervous system,” Dr. Bauer points out, and they immediately pick up when your hormones are spiking.
To explain how estrogen impacts smell, Dr. Brauer zooms in closer: The olfactory pathway—from the lining of the inside of your nose to the brain’s scent-processing centers—is dotted with these receptors. When estrogen levels spike, smells can register as more intense. Sometimes that intensity reads as pleasurable, like during ovulation (we’ll get into that shortly); other times, though, it can be overwhelming, which is how I felt when I was rummaging through my fragrance collection, desperate to find anything that wouldn’t make me want to hurl.
Human chorionic gonadotropin (hCG)
For pregnant people, another hormone enters the mix: The aforementioned human chorionic gonadotropin, or hCG, is the hormone that indicates you’re pregnant when you take an at-home test. Produced by the placenta, hCG supports fetal development by signaling the body to maintain the pregnancy and suppress hormones that cause menstruation. It also helps with immune tolerance, ensuring that the mother's body does not reject the embryo.
“There are receptors for hCG in your central nervous system, too, which can increase the sensation of nausea,” says Dr. Brauer. Nausea itself can heighten aversion, turning once-loved sensory notes into instant triggers. I felt so seen when she told me this; even the mildest eau de toilettes in my fragrance wardrobe had made me feel ill.
Progesterone
Progesterone, which is produced in the ovaries after ovulation and is responsible for regulating your menstrual cycle, is another hormone you’ll hear the doctor mention during pregnancy check-ups. Across the months, progesterone steadily increases, helping to thicken the uterine lining, and peaks right before you give birth.
“Progesterone likely contributes to olfactory changes in pregnancy through its effects on the central nervous system and sensory processing,” says Maral Malekzadeh, MD, a board-certified gynecologist in Cleveland and co-owner of The Well Westlake. But, she adds, progesterone doesn’t contribute to changes in your sense of smell as significantly as estrogen or hCG.
Menstruation
Finding out that my hormones can affect how I perceive smell prompted me to look back more generally on my relationship with perfume. I wondered whether the subtle shifts I’d noticed over the years—craving syrupy gourmands one week, deeper musks the next—were also hormonal.
Until recently, I thought vibes guided me to reach for certain scents day-to-day, but Dr. Malekzadeh says otherwise: “Across the menstrual cycle, estrogen and progesterone fluctuate in a coordinated pattern, and during ovulation, some people report being sensitive to perfumes. Estrogen, specifically, rises during the follicular phase and during ovulation,” she continues, “[and] some people report heightened olfactory sensitivity.”
During the lead-up to ovulation, you also experience a slight increase in testosterone. This combination sometimes causes an uptick in sex drive, says Dr. Malekzadeh. While the science is nuanced and fragrance perception is complex (shaped by psychology, chemistry, environmental context, and biology), you can generalize that this surge of randiness can make certain fragrance notes feel more compelling. Some people report subtle shifts in attraction to body scent. Musk and warm, amber scents, for instance, may read as more intimate. In short, when your body is primed for connection, your nose might be too.
Birth control
So what happens when you throw birth control into the mix? Both doctors Brauer and Malekzadeh explain that oral hormonal contraception works by altering hormone levels, ultimately suppressing ovulation. This can affect the body in several ways, such as mood changes, sudden breakouts, and sore breasts (basically, everything you love about having your period).
As we’ve discussed, changes in sex hormones (estrogen and testosterone) can also influence libido and how you respond to certain scents. In studies examining immune system genes, known as the major histocompatibility complex, or MHC, women often preferred the body odor of men whose immune systems were genetically different from their own, a pairing scientists believe could potentially lead to stronger immune defenses in children. But here’s the thing: Researchers also found that women taking hormonal birth control prefer scents of men with more similar immunity genes to their own.
The theory is that because the pill alters hormonal signals in the body, it may subtly change the way we perceive and respond to scent. It's important to note, however, that this area of science is still largely unexplored, and there isn’t yet concrete evidence that largely shows how birth control, specifically, affects your sense of smell or fragrance preferences.
Perimenopause and menopause
As estrogen levels fluctuate during perimenopause and decline in menopause, you may start to experience symptoms you’ve never had before, like hot flashes, weight gain, and mood swings. Even your sense of smell might shift during this time. “Some [women] report changes in smell sensitivity, scent tolerance, or fragrance preference,” says Dr. Malekzadeh. But there isn’t one universal pattern; some people experience heightened sensitivity, while others notice the opposite.
A 2025 study found that postmenopausal women can experience a diminished sense of smell. What could that look like in your daily life? You might find yourself reaching for fragrance less often, not because it suddenly repels you, but because it doesn’t register as strongly as it once did. You may also find yourself gravitating to bolder, more potent scents simply because they’re easier to perceive.
A Final Word About Hormones and Scent
What can you do when your favorite fragrance suddenly makes you recoil? Dr. Brauer’s best advice is to avoid these kinds of triggers. “It’s unfortunate for someone who likes perfume or previously liked certain smells but can't tolerate them anymore,” she says. Thankfully, though, my aversion to most scents mellowed out in my second trimester, and the same can be said for many women during pregnancy. If your shift in scent preferences seems more permanent, you can at least take solace in the fact that you’re not alone—there’s probably a Reddit thread out there that can function as a support group until your nose sorts things out.
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