    <SEC-DOCUMENT>0001193125-24-083464-index.html : 20240401
    <SEC-HEADER>0001193125-24-083464.hdr.sgml : 20240401
    <ACCEPTANCE-DATETIME>20240401163206
    ACCESSION NUMBER:		0001193125-24-083464
    CONFORMED SUBMISSION TYPE:	ARS
    PUBLIC DOCUMENT COUNT:		1
    CONFORMED PERIOD OF REPORT:	20231231
    FILED AS OF DATE:		20240401
    DATE AS OF CHANGE:		20240401
    EFFECTIVENESS DATE:		20240401

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			REPLIGEN CORP
    		CENTRAL INDEX KEY:			0000730272
    		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
    		ORGANIZATION NAME:           	03 Life Sciences
    		IRS NUMBER:				042729386
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		ARS
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-14656
    		FILM NUMBER:		24809934

    	BUSINESS ADDRESS:
    		STREET 1:		41 SEYON STREET
    		STREET 2:		BUILDING 1, SUITE 100
    		CITY:			WALTHAM
    		STATE:			MA
    		ZIP:			02453
    		BUSINESS PHONE:		7814499560

    	MAIL ADDRESS:
    		STREET 1:		41 SEYON STREET
    		STREET 2:		BUILDING 1, SUITE 100
    		CITY:			WALTHAM
    		STATE:			MA
    		ZIP:			02453
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>ARS
    <SEQUENCE>1
    <FILENAME>d803642dars.pdf
    <DESCRIPTION>ARS
    <TEXT>
    Document 1 - file: d803642dars.pdf

    </DOCUMENT>
    </SEC-DOCUMENT>