Recovery and rehabilitation
Smell training.
Smell training — also called olfactory training — is a structured rehabilitation technique with the strongest evidence base of any intervention for acquired smell loss. It is not a cure, and it is not guaranteed, but it is currently the most well-supported, low-cost, low-risk option available.
What it is and what it does
Smell training was developed by Professor Thomas Hummel at the University of Dresden. The technique is straightforward: deliberate, focused exposure to a fixed set of scents, done consistently over weeks or months. The evidence for benefit in post-viral and post-traumatic smell loss is now substantial — multiple systematic reviews and meta-analyses through 2025 conclude that olfactory training improves smell function in a meaningful share of patients with acquired anosmia, particularly post-COVID.
Smell training cannot restore the sense of smell in people with congenital anosmia, because the underlying olfactory pathway has never developed. It is also not a guaranteed cure for acquired anosmia. But for people with acquired olfactory dysfunction, the evidence-to-effort ratio is the best of anything currently available.
How to do it
The classic protocol uses four scents: rose, lemon, clove, and eucalyptus. You smell each one, deliberately and with focus, for about 20 seconds, twice a day, every day, for at least 12 weeks.
Many clinicians now recommend extending past three months and rotating in additional scent sets — the modified olfactory training protocol used in COVID-related research extends the program to 36 weeks with 12 scents total. The exact scents matter less than consistency and deliberate, attentive exposure.
What to expect
Recovery, when it happens, is usually gradual and uneven. Many people report that strong primary scents return first, followed by more complex aromas. Parosmia — distortion of smells, where coffee or garlic or meat smell wrong or repulsive — often gets worse before getting better.
Consistency is more important than intensity. Two minutes a day, every day, for three months will outperform an occasional hour-long session. Treat it like physical therapy: small, repeated, attentive.
Where to get scent kits
Several reputable organizations sell or recommend training kits. AbScent’s Snift kits are widely used and were developed specifically for smell training. A number of independent suppliers sell similar kits, and you can also assemble your own with high-quality essential oils — the oils themselves are the active component, and the brand matters less than the freshness and concentration.
We do not sell kits and do not earn commission from any vendor. This page exists as guidance only.
Talk to a specialist
Smell training is most effective when paired with evaluation by an ENT or smell-and-taste specialist who can identify treatable underlying causes — sinus disease, polyps, medication effects — and rule out conditions that require different treatment. If something other than viral or traumatic loss is contributing to your anosmia, smell training alone won’t address it.
Where to go next
Find a specialist or kit supplier.
The Resources page lists clinics with documented experience in olfactory dysfunction and reputable suppliers of smell training kits.