<SEC-DOCUMENT>0001104659-18-000739-index.html : 20180104
<SEC-HEADER>0001104659-18-000739.hdr.sgml : 20180104
<ACCEPTANCE-DATETIME>20180104150505
ACCESSION NUMBER:		0001104659-18-000739
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20180104
DATE AS OF CHANGE:		20180104

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Flex Pharma, Inc.
		CENTRAL INDEX KEY:			0001615219
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				465087339
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-88731
		FILM NUMBER:		18509780

	BUSINESS ADDRESS:	
		STREET 1:		800 BOYLSTON STREET
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199
		BUSINESS PHONE:		617-874-1821

	MAIL ADDRESS:	
		STREET 1:		800 BOYLSTON STREET
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRIMECAP MANAGEMENT CO/CA/
		CENTRAL INDEX KEY:			0000763212
		IRS NUMBER:				953868081

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
		BUSINESS PHONE:		6263049222

	MAIL ADDRESS:	
		STREET 1:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>a18-2177_3sc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: a18-2177_3sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>