Diphenhydramine
As of the edition of 20 October 2026, Diphenhydramine is a small molecule: marketed, first approved in 1962 (ES); acts on HRH1.
Sources: FDA Orange Book and Purple Book, other approval registers, ClinicalTrials.gov, ChEMBL.
The drug
- Status
- Marketed; latest approval 2001
- Kind
- Small molecule
- Brand name
- Benadryl
- First approved
- 1 April 1962 (ES)
- Approvals on record
- 26 in 4 regions
- Holder of the most recent approval
- Medtech; 9 holders in all
- Registered trials
- 146, 30 stopped early
- Disease areas
- Cancer; Immune system; Blood and lymph; Nervous system; Urinary and reproductive; Lungs and airways
US protection
No US approval on record.
With no US approval on record there are no listed US patents or exclusivities.
This is the US only.
Companies that need a new molecule because of this drug
2 companies on route B because of this drug.
Companies on route B for this drug
In the product2 companies are on route B because of Diphenhydramine.
See the 2 companies on route B for this drug, with the facts behind eachRequest access. Nothing is shown until you do.
Target
| Gene | Protein | UniProt |
|---|---|---|
| HRH1 | Histamine H1 receptor | P35367 |
Registered trials
| Phase | Trials | Completed | Active | Stopped early |
|---|---|---|---|---|
| Phase not stated | 17 | 5 | 2 | 5 |
| Phase 1 | 32 | 23 | 3 | 6 |
| Phase 2 | 57 | 28 | 14 | 13 |
| Phase 3 | 22 | 7 | 10 | 4 |
| Phase 4 | 18 | 13 | 2 | 2 |
| All trials | 146 |
Who has held its approvals
| Company | Role | Years |
|---|---|---|
| Medtech | Applicant | 1979 to now |
| Johnson & Johnson | Acquired holder, Later holder and Lead sponsor of trials | 2006 to now |
| Pfizer | Applicant, Later holder and Lead sponsor of trials | 2013 to now |
| Bayer | Later holder and Lead sponsor of trials | 2015 to now |