Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 10, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Trading Symbol	IMPL
Entity Registrant Name	IMPEL PHARMACEUTICALS INC.
Entity Central Index Key	0001445499
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-40353
Entity Tax Identification Number	26-3058238
Entity Address, Address Line One	201 Elliott Avenue West
Entity Address, Address Line Two	Suite 260
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98119
City Area Code	206
Local Phone Number	568-1466
Entity Common Stock, Shares Outstanding		23,738,813
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false