Phantom Smells in Perimenopause: Why You're Sniffing Things That Aren't There

What Are Phantom Smells — and What's the Difference From Distorted Smells?

Phantom smell has a clinical name: phantosmia. It means your brain perceives an odor when there is no actual scent molecule reaching your nose. The experience can feel completely real — vivid enough to make you check the stove or step outside looking for the source.

A related but distinct experience is parosmia: this is when a real smell reaches your nose but your brain interprets it incorrectly. Coffee might smell like burning plastic, or a floral scent might turn chemical. Both phantosmia and parosmia can occur during hormonal transitions.

• Phantosmia: smelling an odor with no external source — the smell is entirely generated by your brain or nerve signals
• Parosmia: a real smell is present but perceived as something completely different, often unpleasant
• Hyperosmia: heightened sensitivity to smells that do exist — also reported in perimenopause
• Hyposmia: reduced ability to smell — more common post-menopause than during perimenopause

Why Perimenopause Can Affect Your Sense of Smell

Estrogen plays a quiet but important role in the olfactory system — the network of neurons responsible for detecting and processing smell. Estrogen receptors are present in olfactory neurons, and the hormone appears to support both the maintenance and sensitivity of these cells. When estrogen levels begin to fluctuate unpredictably during perimenopause, those neurons can behave erratically.

The result can be brief episodes of smelling something that isn't there, or perceiving a familiar smell in a distorted way. These episodes are typically intermittent — lasting seconds to a few minutes — and then resolve on their own. They tend to be most noticeable during phases of lower estrogen, though tracking this precisely is difficult given how variable hormone levels are throughout the menstrual cycle in perimenopause.

It is worth noting that most formal research on smell and menopause focuses on the post-menopause years, when estrogen has stabilized at a lower baseline. The perimenopause-specific picture is less studied, which means the true prevalence of phantosmia in this transition is not yet well established.

The Most Common Phantom Smells Women Report

The specific odor that shows up in phantosmia varies from person to person, but certain descriptions come up repeatedly in clinical reports and community accounts:

• Cigarette smoke or burning tobacco — often the most frequently reported
• Something burning — electrical, wood, or an unidentifiable burning scent
• Chemical odors — bleach, ammonia, or a sharp synthetic smell
• Sweet or cloying odors — sometimes described as artificial or syrupy
• Metallic odors — a sharp, almost blood-like or iron scent
• Rotting or spoiled smells — less common but reported by some women

Most episodes are brief and resolve without any intervention. Some women notice they occur at a particular time of day, during stress, or around certain hormonal phases of their cycle.

Other Causes Worth Knowing About

Hormonal change is one explanation for phantom smells during this life stage, but it is not the only one. Because phantosmia can occasionally signal something that needs medical attention, it is worth being aware of other causes — especially those that carry specific warning signs.

Migraine With Olfactory Aura

Migraine aura can involve sensory disturbances including smell. An olfactory aura typically precedes or accompanies a headache. If your phantom smell episodes consistently happen alongside or just before a headache, migraine is a strong possibility and worth discussing with your doctor.

Sinus and Nasal Conditions

Nasal polyps, chronic sinusitis, or active infection can irritate olfactory nerve endings and produce phantom smells. These are often accompanied by other nasal symptoms — congestion, post-nasal drip, or reduced smell overall — which can help differentiate them from a hormonal cause.

COVID-19 Aftermath

Post-COVID smell disturbances — including both parosmia and phantosmia — are well recognized and can persist for months after infection. If phantom or distorted smells began after a COVID-19 illness, this is the most likely explanation regardless of your perimenopause status.

Temporal Lobe Seizures

The temporal lobe of the brain is involved in smell processing. Seizures originating in this area can produce brief olfactory hallucinations — often described as burning or chemical odors. These episodes are usually very short, may be accompanied by a sense of altered consciousness or confusion, and always warrant medical evaluation.

Neurological Conditions (Rare)

Changes in smell can be an early feature of some neurological conditions including Parkinson's disease and, less commonly, early Alzheimer's. It is important to note that in these conditions, the more typical change is reduced ability to smell (hyposmia), rather than phantom smells. Isolated episodes of phantosmia without other neurological symptoms are generally not a marker of these conditions.

Red Flags: When to Seek Evaluation Promptly

Most phantom smell episodes during perimenopause do not require urgent action. However, certain patterns are red flags that should prompt you to contact a healthcare provider or, in some cases, seek emergency care:

• Sudden onset of phantom smell accompanied by a severe or unusual headache
• Any episode with confusion, memory gap, or a feeling of altered awareness — could suggest a seizure
• Loss of consciousness, even briefly
• Phantom smells that occur alongside fever, which can signal an infection affecting the brain
• Episodes that are increasing in frequency or intensity over weeks
• New phantom smells following a head injury
• Phantom smells combined with vision changes, speech difficulty, or weakness on one side of the body

If any of the above apply, do not wait for a routine appointment. The combination of a phantom smell with neurological symptoms needs same-day or emergency evaluation.

What You Can Do

If your episodes are brief, infrequent, and not accompanied by any of the red flags above, there is a good chance they are hormonally driven and will fluctuate with your hormonal pattern — or ease after menopause when estrogen stabilizes, even at a lower level.

• Keep a brief log of episodes — note the time, duration, the smell, and anything that preceded it (stress, poor sleep, phase of cycle). Patterns can be helpful if you bring this to a doctor
• Mention it at your next perimenopause or primary care appointment — even if it feels too minor to raise. Your provider can rule out sinus, neurological, or other causes with a focused history
• Hormone replacement therapy (HRT): some evidence suggests that estrogen support may help with olfactory disturbances driven by estrogen deficiency, though research specific to phantosmia in perimenopause is limited. If you are already discussing HRT for other symptoms, this is worth adding to the conversation
• Address contributing factors: sleep deprivation and high stress can increase the frequency of many perimenopausal symptoms, potentially including olfactory ones
• If migraines are suspected, a headache diary can help identify triggers and support a migraine diagnosis with your doctor

The Bottom Line on Phantom Smells in Perimenopause

Smelling things that aren't there is unsettling by nature — your senses are supposed to be reliable reporters of the world around you, and when one goes rogue it can shake your confidence in what's real. But in the context of perimenopause, brief, intermittent episodes of phantom smell without accompanying neurological symptoms are generally not a sign of anything dangerous.

Fluctuating estrogen affecting olfactory neurons is a plausible and underrecognized explanation. It does not mean something is permanently wrong with your sense of smell or your brain. Most women find these episodes come and go, and many see improvement as their hormonal landscape settles.

The key is knowing your red flags, mentioning this to your provider so other causes can be excluded, and giving yourself permission to take your own symptoms seriously — even the strange ones.