Intranasal Insulin
Insulin, Human (Recombinant) -- Intranasal Administration
The largest Phase 2/3 trial (SNIFF main, n=240) failed its primary cognitive endpoint, and no FDA-approved intranasal insulin product exists. Evidence is strongest for postoperative delirium prevention but mixed for the flagship Alzheimer's/MCI indication.
Insulin sprayed into the nose travels directly along nerve pathways into the brain, where it activates receptors that improve memory, protect brain cells, and reduce inflammation -- all without significantly affecting blood sugar levels. It is being studied for Alzheimer's disease, surgical delirium prevention, and restoring sense of smell.
This entry is a cited research summary, not an established treatment reference. Dosing language is included as source context, not as medical instruction.
Intranasal Insulin has substantial clinical evidence but is not FDA-approved.
The largest Phase 2/3 trial (SNIFF main, n=240) failed its primary cognitive endpoint, and no FDA-approved intranasal insulin product exists. Evidence is strongest for postoperative delirium prevention but mixed for the flagship Alzheimer's/MCI indication.
Safety Summary
Schmid 2018 safety review PMID 29508509 encompassing 56 clinical studies (~1,924 participants: 1,092 acute, 832 longer-term up to 9.7 years) reported NO cases of symptomatic hypoglycemia or severe adverse events attributable to intranasal human insulin at standard doses. Most AEs were transient local nasal effects. Dose-dependent hypoglycemia risk profile: 20--80 IU = no clinical hypoglycemia reported in trials PMID 33721199; up to 160 IU = tolerated without consistent hypoglycemia in perioperative dose-escalation PMC10897660; 240 IU = hypoglycemia in 2/3 patients in one series PMC10897660; 600 IU = 2 hypoglycemic events (1 severe at 24 mg/dL, 1 mild at 51 mg/dL) in adaptive dose-escalation study PMC11573730. Nasal mucosal safety: 4-month human data showed no significant mucosal damage PMID 3315514; animal studies show insulin promotes nasal mucosal healing PMID 36384319 and olfactory epithelium protection PMC8733614. Systemic bioavailability is low (~1--2% without enhancers, ~10--15% with optimized devices; PMC2769806). [.json]
Clinical check-in
If real-world use or exposure is being considered, review potential interactions, contraindications, and monitoring needs with a licensed clinician rather than relying on summary copy alone.
Cited sources
Every claim on this page links to one of the 7 sources below. Identifiers are PubMed (PMID), ClinicalTrials.gov (NCT), or DOI; click through to the source of record before acting on a claim.
- 1PMID 32568367PubMed
- 2PMID 22156547PubMed
- 3PMID 41057918PubMed
- 4PMID 29508509PubMed
- 6PMID 35482079PubMed
- 7PMID 29557250PubMed
- 15NCT02988401ClinicalTrials.gov