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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 IhunM9lPdV/2THhsUtzzj3hTX7EfZ5Cidb+l2l1+N86IaVpi+TdzV5EV4JlpSl3y
 Hbq69dKFAIPeA6lXyHCP3g==

<SEC-DOCUMENT>0001140361-11-003351.txt : 20110119
<SEC-HEADER>0001140361-11-003351.hdr.sgml : 20110119
<ACCEPTANCE-DATETIME>20110119165518
ACCESSION NUMBER:		0001140361-11-003351
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110112
FILED AS OF DATE:		20110119
DATE AS OF CHANGE:		20110119

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kollender Richard S
		CENTRAL INDEX KEY:			0001415666

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30739
		FILM NUMBER:		11536257

	MAIL ADDRESS:	
		STREET 1:		C/O QUAKER BIOVENTURES, CIRA CENTRE
		STREET 2:		2929 ARCH STREET, 3RD FLOOR
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19104-2868

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			INSMED INC
		CENTRAL INDEX KEY:			0001104506
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				541972729
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1201

	BUSINESS ADDRESS:	
		STREET 1:		8720 STONY POINT PARKWAY
		STREET 2:		SUITE 200
		CITY:			RICHMOND
		STATE:			VA
		ZIP:			23235
		BUSINESS PHONE:		804-565-3000

	MAIL ADDRESS:	
		STREET 1:		8720 STONY POINT PARKWAY
		STREET 2:		SUITE 200
		CITY:			RICHMOND
		STATE:			VA
		ZIP:			23235
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2011-01-12</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001104506</issuerCik>
        <issuerName>INSMED INC</issuerName>
        <issuerTradingSymbol>INSM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001415666</rptOwnerCik>
            <rptOwnerName>Kollender Richard S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O INSMED INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>8720 STONY POINT PKWY, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>RICHMOND</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>23235</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4826953</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Issued to Quaker BioVentures II, L.P. in connection with the Merger.  Richard Kollender is a partner</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>54687.50</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Kollender disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F2">The RSU's have a one year cliff vesting period, provided that the director attends at least 75% of the meetings of the Board.</footnote>
        <footnote id="F3">The RSU's will be settled in a lump sum cash payment upon vesting; provided, however, that if the Company's shareholders approve an amendment to the Company's Amended &amp; Restated 2000 Stock Incentive Plan to increase the number of shares of common stock that may be issued under the plan or additional shares become available to the plan through stock option expirations and/or employee terminations, the Company may settle the RSU's in shares of common stock in lieu of cash.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Richard Kollender</signatureName>
        <signatureDate>2011-01-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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