Cover - shares	3 Months Ended
	Mar. 31, 2023	May 06, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-40034
Entity Registrant Name	GRI BIO, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4369909
Entity Address, Address Line One	2223 Avenida de la Playa
Entity Address, Address Line Two	#208
Entity Address, City or Town	La Jolla
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92037
City Area Code	619
Local Phone Number	400-1170
Title of 12(b) Security	Common Stock, par value $0.0001per share
Trading Symbol	GRI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		2,918,954
Entity Central Index Key	0001824293
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false