    <SEC-DOCUMENT>0001047469-17-005536-index.html : 20170905
    <SEC-HEADER>0001047469-17-005536.hdr.sgml : 20170904
    <ACCEPTANCE-DATETIME>20170905142523
    ACCESSION NUMBER:		0001047469-17-005536
    CONFORMED SUBMISSION TYPE:	S-1
    PUBLIC DOCUMENT COUNT:		47
    FILED AS OF DATE:		20170905
    DATE AS OF CHANGE:		20170905

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			RHYTHM PHARMACEUTICALS, INC.
    		CENTRAL INDEX KEY:			0001649904
    		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
    		IRS NUMBER:				462159271
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		S-1
    		SEC ACT:		1933 Act
    		SEC FILE NUMBER:	333-220337
    		FILM NUMBER:		171068298

    	BUSINESS ADDRESS:
    		STREET 1:		500 BOYLSTON STREET
    		STREET 2:		11TH FLOOR
    		CITY:			BOSTON
    		STATE:			MA
    		ZIP:			02116
    		BUSINESS PHONE:		857-264-4280

    	MAIL ADDRESS:
    		STREET 1:		500 BOYLSTON STREET
    		STREET 2:		11TH FLOOR
    		CITY:			BOSTON
    		STATE:			MA
    		ZIP:			02116

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	RHYTHM METABOLIC, INC.
    		DATE OF NAME CHANGE:	20150803
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>S-1
    <SEQUENCE>1
    <FILENAME>a2233117zs-1.htm
    <DESCRIPTION>S-1
    <TEXT>
    Document 1 - file: a2233117zs-1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-3.1
    <SEQUENCE>2
    <FILENAME>a2233117zex-3_1.htm
    <DESCRIPTION>EX-3.1
    <TEXT>
    Document 2 - file: a2233117zex-3_1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-3.2
    <SEQUENCE>3
    <FILENAME>a2233117zex-3_2.htm
    <DESCRIPTION>EX-3.2
    <TEXT>
    Document 3 - file: a2233117zex-3_2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-4.2
    <SEQUENCE>4
    <FILENAME>a2233117zex-4_2.htm
    <DESCRIPTION>EX-4.2
    <TEXT>
    Document 4 - file: a2233117zex-4_2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.3
    <SEQUENCE>5
    <FILENAME>a2233117zex-10_3.htm
    <DESCRIPTION>EX-10.3
    <TEXT>
    Document 5 - file: a2233117zex-10_3.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.4
    <SEQUENCE>6
    <FILENAME>a2233117zex-10_4.htm
    <DESCRIPTION>EX-10.4
    <TEXT>
    Document 6 - file: a2233117zex-10_4.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.5
    <SEQUENCE>7
    <FILENAME>a2233117zex-10_5.htm
    <DESCRIPTION>EX-10.5
    <TEXT>
    Document 7 - file: a2233117zex-10_5.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.6
    <SEQUENCE>8
    <FILENAME>a2233117zex-10_6.htm
    <DESCRIPTION>EX-10.6
    <TEXT>
    Document 8 - file: a2233117zex-10_6.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.7
    <SEQUENCE>9
    <FILENAME>a2233117zex-10_7.htm
    <DESCRIPTION>EX-10.7
    <TEXT>
    Document 9 - file: a2233117zex-10_7.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.8
    <SEQUENCE>10
    <FILENAME>a2233117zex-10_8.htm
    <DESCRIPTION>EX-10.8
    <TEXT>
    Document 10 - file: a2233117zex-10_8.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.9
    <SEQUENCE>11
    <FILENAME>a2233117zex-10_9.htm
    <DESCRIPTION>EX-10.9
    <TEXT>
    Document 11 - file: a2233117zex-10_9.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.11
    <SEQUENCE>12
    <FILENAME>a2233117zex-10_11.htm
    <DESCRIPTION>EX-10.11
    <TEXT>
    Document 12 - file: a2233117zex-10_11.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.12
    <SEQUENCE>13
    <FILENAME>a2233117zex-10_12.htm
    <DESCRIPTION>EX-10.12
    <TEXT>
    Document 13 - file: a2233117zex-10_12.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.15
    <SEQUENCE>14
    <FILENAME>a2233117zex-10_15.htm
    <DESCRIPTION>EX-10.15
    <TEXT>
    Document 14 - file: a2233117zex-10_15.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.16
    <SEQUENCE>15
    <FILENAME>a2233117zex-10_16.htm
    <DESCRIPTION>EX-10.16
    <TEXT>
    Document 15 - file: a2233117zex-10_16.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.17
    <SEQUENCE>16
    <FILENAME>a2233117zex-10_17.htm
    <DESCRIPTION>EX-10.17
    <TEXT>
    Document 16 - file: a2233117zex-10_17.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.20
    <SEQUENCE>17
    <FILENAME>a2233117zex-10_20.htm
    <DESCRIPTION>EX-10.20
    <TEXT>
    Document 17 - file: a2233117zex-10_20.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-23.1
    <SEQUENCE>18
    <FILENAME>a2233117zex-23_1.htm
    <DESCRIPTION>EX-23.1
    <TEXT>
    Document 18 - file: a2233117zex-23_1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>g208422lmi001.jpg
    <DESCRIPTION>G208422LMI001.JPG
    <TEXT>
    Document 19 - file: g208422lmi001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>g208422loi001.jpg
    <DESCRIPTION>G208422LOI001.JPG
    <TEXT>
    Document 20 - file: g208422loi001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>g208422lqi001.jpg
    <DESCRIPTION>G208422LQI001.JPG
    <TEXT>
    Document 21 - file: g208422lqi001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>g208422lu13i001.jpg
    <DESCRIPTION>G208422LU13I001.JPG
    <TEXT>
    Document 22 - file: g208422lu13i001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>g208422lu17i001.jpg
    <DESCRIPTION>G208422LU17I001.JPG
    <TEXT>
    Document 23 - file: g208422lu17i001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>g208422lu21i001.jpg
    <DESCRIPTION>G208422LU21I001.JPG
    <TEXT>
    Document 24 - file: g208422lu21i001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>g208422lwi001.gif
    <DESCRIPTION>G208422LWI001.GIF
    <TEXT>
    Document 25 - file: g208422lwi001.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>g208422lyi001.jpg
    <DESCRIPTION>G208422LYI001.JPG
    <TEXT>
    Document 26 - file: g208422lyi001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>g460244.jpg
    <DESCRIPTION>G460244.JPG
    <TEXT>
    Document 27 - file: g460244.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>28
    <FILENAME>g218986.jpg
    <DESCRIPTION>G218986.JPG
    <TEXT>
    Document 28 - file: g218986.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>29
    <FILENAME>g225101.jpg
    <DESCRIPTION>G225101.JPG
    <TEXT>
    Document 29 - file: g225101.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>30
    <FILENAME>g661438.jpg
    <DESCRIPTION>G661438.JPG
    <TEXT>
    Document 30 - file: g661438.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>31
    <FILENAME>g708972.jpg
    <DESCRIPTION>G708972.JPG
    <TEXT>
    Document 31 - file: g708972.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>32
    <FILENAME>g875750.jpg
    <DESCRIPTION>G875750.JPG
    <TEXT>
    Document 32 - file: g875750.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>33
    <FILENAME>g704505.jpg
    <DESCRIPTION>G704505.JPG
    <TEXT>
    Document 33 - file: g704505.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>34
    <FILENAME>g1037560.jpg
    <DESCRIPTION>G1037560.JPG
    <TEXT>
    Document 34 - file: g1037560.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>35
    <FILENAME>g1006537.jpg
    <DESCRIPTION>G1006537.JPG
    <TEXT>
    Document 35 - file: g1006537.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>36
    <FILENAME>g69779.jpg
    <DESCRIPTION>G69779.JPG
    <TEXT>
    Document 36 - file: g69779.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>37
    <FILENAME>g24116.jpg
    <DESCRIPTION>G24116.JPG
    <TEXT>
    Document 37 - file: g24116.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>38
    <FILENAME>g893313.jpg
    <DESCRIPTION>G893313.JPG
    <TEXT>
    Document 38 - file: g893313.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>39
    <FILENAME>g612255.jpg
    <DESCRIPTION>G612255.JPG
    <TEXT>
    Document 39 - file: g612255.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>40
    <FILENAME>g748634.jpg
    <DESCRIPTION>G748634.JPG
    <TEXT>
    Document 40 - file: g748634.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>41
    <FILENAME>g1001182.jpg
    <DESCRIPTION>G1001182.JPG
    <TEXT>
    Document 41 - file: g1001182.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>42
    <FILENAME>g150005.jpg
    <DESCRIPTION>G150005.JPG
    <TEXT>
    Document 42 - file: g150005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>43
    <FILENAME>g610761.jpg
    <DESCRIPTION>G610761.JPG
    <TEXT>
    Document 43 - file: g610761.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>44
    <FILENAME>g886741.jpg
    <DESCRIPTION>G886741.JPG
    <TEXT>
    Document 44 - file: g886741.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>45
    <FILENAME>g862874.jpg
    <DESCRIPTION>G862874.JPG
    <TEXT>
    Document 45 - file: g862874.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>46
    <FILENAME>g227846.jpg
    <DESCRIPTION>G227846.JPG
    <TEXT>
    Document 46 - file: g227846.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>47
    <FILENAME>g394599.jpg
    <DESCRIPTION>G394599.JPG
    <TEXT>
    Document 47 - file: g394599.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>