British Rhinological Society Smell Training Guideline-key Takeaways
- 01. What the guideline is trying to do
- 02. Key smell-training protocol
- 03. Schedule you can follow
- 04. Who should be offered training
- 05. How clinicians should support patients
- 06. Testing and imaging: what the guideline discourages
- 07. Odor selection and consistency
- 08. What results to expect (and when)
- 09. Historical context and consensus evolution
- 10. Implementation details for real-world adherence
- 11. Safety considerations and boundaries
- 12. Quick-start checklist
The British Rhinological Society's smell training guideline boils down to a simple, repeatable protocol: patients with persistent smell loss should regularly sniff a set of strong, distinct odors (typically at least four), using a structured schedule for several months-while clinicians coordinate supportive care and avoid unnecessary testing when smell loss is attributed to COVID-19.
What the guideline is trying to do
The core goal of the smell training guideline is to increase the odds of improving smell function after injury to the olfactory system, especially when recovery is delayed. The approach is grounded in the clinical logic that repeated, targeted odor exposure may "re-teach" aspects of olfactory processing, and major consensus statements around olfactory training have repeatedly recommended it when smell loss persists.
Key smell-training protocol
The British Rhinological Society's consensus-based recommendations emphasize structured exposure rather than casual scent "sniffing," so the odor exposure routine becomes a consistent therapy. In the widely used protocol format reflected in related guideline summaries, patients sniff each selected odor for a sustained period (often at least 20 seconds), multiple times per day, for a minimum multi-month course.
- Pick a small set of distinct odor categories (commonly four "anchors" used in many protocols: rose, eucalyptus, lemon, clove).
- Sniff each odor deliberately for long enough to register it (commonly at least 20 seconds per odor).
- Repeat the sequence multiple times daily (commonly at least two times per day).
- Continue for several months (commonly 3-6 months or longer), because olfactory recovery-when it happens-often tracks over weeks rather than days.
Schedule you can follow
A practical interpretation of the guideline is to treat smell training like rehabilitation: consistent timing, consistent exposures, and enough duration to matter biologically. The repeatedly cited structure in guideline-level summaries is "minimum daily reps" across "multi-month" timelines, which is why clinicians often counsel patients to stay on the regimen even when immediate improvement is subtle.
- Morning session: sniff each chosen odor (minimum duration per odor) and complete the full set once.
- Midday/afternoon or evening session: repeat the full odor set again (minimum daily frequency).
- Daily adherence: keep the routine stable for the entire training window (minimum course length).
- Re-evaluation: reassess symptoms and progress near the mid-course (and again after the full course) rather than stopping early.
Who should be offered training
In COVID-19-associated smell loss contexts, the British Rhinological Society consensus (published in 2020) recommended olfactory training for patients with persistent smell loss lasting beyond about two weeks. That threshold matters because it shifts eligibility from "wait and see" toward "begin structured therapy early enough to plausibly influence recovery."
How clinicians should support patients
Beyond the patient routine, guideline-level messaging includes practical clinical support-especially in early phases where care pathways need to be clear and not over-medicalized. One summary of the British Rhinological Society guidance notes a structured GP care plan for the first three months and that if specialist input is needed, it may be handled via phone or video consultation, which affects how follow-up care is organized.
Testing and imaging: what the guideline discourages
A strong utility detail for patients and clinicians alike is what not to do: in COVID-19-related smell loss, guideline summaries report that an MRI brain scan was not considered appropriate in any case where COVID-19 was the cause. This is a meaningful resource stewardship signal, because it prevents unnecessary investigations that rarely change management when the condition is already being addressed with established conservative therapy.
Odor selection and consistency
Most smell-training protocols use a small, repeatable set of odors to standardize the experience, which improves adherence and makes progress easier to track. Common selections include rose (phenylethyl alcohol), eucalyptus (eucalyptol), lemon (citronellal), and clove (eugenol), and these odorants are frequently referenced in clinical practice summaries of olfactory training.
What results to expect (and when)
Clinically, the biggest mistake patients make is expecting immediate, day-one changes and discontinuing after a brief trial, even though guideline-style protocols are built around multi-month dosing. For expectation setting, the commonly cited training duration in olfactory training guidance summaries is 3-6 months (or longer), which aligns with the time window many patients and clinicians use to decide whether to continue, adjust, or re-assess.
| Element of training | Typical guideline-style target | Why it matters |
|---|---|---|
| Odor set | 4 distinct anchors (rose/eucalyptus/lemon/clove) | Standardization improves adherence and sensory recognition |
| Per-odor sniff duration | At least 20 seconds per odor | Ensures repeated sensory "registration" rather than brief exposure |
| Daily frequency | At least 2 sessions per day | Supports a consistent stimulus schedule |
| Minimum duration | 3-6 months (or longer) | Allows time for gradual functional recovery trajectories |
| COVID-19 imaging | No MRI when COVID-19 is the cause | Reduces low-yield testing and focuses on conservative therapy |
Historical context and consensus evolution
Olfactory training has moved from smaller studies and clinical practice patterns toward broader consensus recommendations across rhinology communities, and the British Rhinological Society's 2020 consensus sits within that evolution. One reference summary notes that in 2017, international and European rhinologic societies recommended smell training, and by 2020 the British Rhinological Society published consensus guidelines specifically for smell loss due to COVID-19-highlighting that consensus building accelerated alongside the pandemic's burden.
"Olfactory training was recommended for all [COVID-19] patients with persistent loss of sense of smell of more than 2 weeks duration."
Implementation details for real-world adherence
To make the guideline operational, patients need a routine that survives weekends, work travel, and "busy days," because adherence is often the variable that differentiates therapy success from failure. Clinicians can reinforce that smell-training protocols are designed as a measured course rather than a quick intervention, and they should help patients set reminders across the full 3-6 month window.
- Use a fixed location (kitchen counter, bedside table) to reduce friction for daily sessions.
- Track completion of each odor set per day, because structured practice tends to outperform sporadic "as-needed" sniffing.
- Plan re-checks at mid-course and near the end of the standard training window to decide on next steps.
Safety considerations and boundaries
Olfactory training is generally conservative and low risk compared with invasive interventions, but it still requires sensible boundaries to avoid harm from overly aggressive scent exposure. The British Rhinological Society approach, as summarized in guideline coverage, focuses on supportive clinical care pathways and avoids unnecessary advanced testing in COVID-19-caused smell loss, which is consistent with low-risk therapy principles.
Quick-start checklist
If you need a fast, actionable summary of the smell training guideline details, treat it like a standardized program: choose scents, follow the cadence, and commit for the recommended duration. Then pair the home routine with structured clinician follow-up as suggested in guideline summaries, particularly during the initial months.
- Select four standardized odorants (rose/eucalyptus/lemon/clove).
- Sniff each odor for at least 20 seconds per odor.
- Do the full set at least twice daily.
- Continue for at least 3-6 months.
- For COVID-19-caused smell loss, follow the recommended care pathway and avoid MRI.
Everything you need to know about British Rhinological Society Smell Training Guideline Key Takeaways
When does smell training start?
Start when smell loss is persistent (for example, COVID-19-related loss beyond roughly two weeks), because the consensus recommendation targets patients unlikely to fully recover immediately without intervention.
How should patients be followed up?
Guidance summaries indicate that GP-led support should cover the initial period (for example, the first three months), with escalation to ENT most likely by phone or video where appropriate.
Should COVID-19 smell loss trigger immediate MRI?
No-according to guideline summaries, MRI brain scanning was not appropriate when COVID-19 was the cause of the smell loss.
Which scents are commonly used?
Protocols frequently standardize four odorants: rose, eucalyptus, lemon, and clove, so patients train with distinct, recognizable scents across the entire course.
What if I don't notice improvement early?
The guideline-style approach supports continuing the regimen for the recommended multi-month duration because immediate changes are not the primary expectation; structured training is built around gradual recovery timelines.