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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\u2014and 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\u2019s 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\u2019t expect any of them to totally rewire my nose.<\/p>\n
Turns out, I wasn\u2019t 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\u2019t the only time this shift can happen, either; any subtle hormonal fluctuations you experience\u2014across your menstrual cycle, during perimenopause, and while using hormonal contraception\u2014can influence how you perceive scent.<\/p>\n
Ahead, experts break down how different hormonal shifts and phases in a woman\u2019s life can impact the sense of smell.<\/p>\n
Brought on by hormonal shifts in pregnancy, changes in how you perceive smell \u201ccommonly happen in the first trimester,\u201d says Dr. Brauer, adding that patients typically complain about a heightened sense of smell. There\u2019s an evolutionary explanation, she explains: \u201cWhen you’re pregnant, your body goes on high alert to protect you and your baby.\u201d For some, that means nausea triggered by everyday smells; for others, this biological reaction means that long-standing fragrance preferences shift overnight.<\/p>\n
There\u2019s also an endocrinological explanation in that the biggest hormonal surge during pregnancy happens during these early weeks. Human chorionic gonadotropin (hCG)\u2014the main pregnancy hormone responsible for fetal development\u2014peaks 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\u2019t the only hormone responsible, estrogen and progesterone also come into play.<\/p>\n
Estrogen<\/strong><\/p>\n 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\u2019s the hormone responsible for the development of breasts during puberty, uterine-lining growth, and the formation of fallopian tubes. \u201cThere are estrogen receptors throughout the entire central nervous system,\u201d Dr. Bauer points out, and they immediately pick up when your hormones are spiking.<\/p>\n To explain how estrogen impacts smell, Dr. Brauer zooms in closer: The olfactory pathway\u2014from the lining of the inside of your nose to the brain\u2019s scent-processing centers\u2014is dotted with these receptors. When estrogen levels spike, smells can register as more intense. Sometimes that intensity reads as pleasurable, like during ovulation (we\u2019ll 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\u2019t make me want to hurl.<\/p>\n Human chorionic gonadotropin (hCG)<\/strong> \u201cThere are receptors for hCG in your central nervous system, too, which can increase the sensation of nausea,\u201d 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.<\/p>\n<\/div>\n
For pregnant people, another hormone enters the mix: The aforementioned human chorionic gonadotropin, or hCG, is the hormone that indicates you\u2019re 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.<\/p>\n