The Science

The Hummel Protocol: A Clinically Proven Approach

Developed in 2009 by Dr. Thomas Hummel at the Smell & Taste Clinic in Dresden, Germany, Olfactory Training is a non-invasive treatment for anosmia (loss of smell) and parosmia (distorted smell). The protocol is based on the concept of neuroplasticity—the brain's ability to reorganize itself by forming new neural connections.

How It Works

The olfactory nerve is unique among cranial nerves because it can regenerate. By exposing the olfactory receptors to four distinct odor categories (floral, fruity, spicy, and resinous) on a daily basis, the training stimulates this regenerative process.

The Four Core Scents (Set 1)

• Rose (Floral): Stimulates receptors sensitive to sweet, botanical compounds.
• Lemon (Fruity): Activates pathways responding to sharp, citrus notes.
• Eucalyptus (Resinous): Triggers the trigeminal nerve, providing a cooling sensation alongside the scent.
• Clove (Spicy): Engages receptors tuned to warm, pungent aromatics.

Clinical Evidence

Numerous peer-reviewed studies have demonstrated the efficacy of this protocol. A landmark study published in The Laryngoscope showed that 30% of patients with post-viral olfactory dysfunction experienced significant improvement after 12 weeks of training, compared to only 6% in the control group.