-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JUssDxrcl0EwX5EqMiZPgGWxsnkOis4gu4KcQiCti9EqCEcZfoM1g0MsD18Og2bi
 XnvIc3F9W4bwvf2q+uoMRw==

<SEC-DOCUMENT>0001140361-07-012955.txt : 20070626
<SEC-HEADER>0001140361-07-012955.hdr.sgml : 20070626
<ACCEPTANCE-DATETIME>20070626122218
ACCESSION NUMBER:		0001140361-07-012955
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070622
FILED AS OF DATE:		20070626
DATE AS OF CHANGE:		20070626

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:			1231

	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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Glover Steve C
		CENTRAL INDEX KEY:			0001304406

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30739
		FILM NUMBER:		07940499

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		954-382-7677

	MAIL ADDRESS:	
		STREET 1:		108 DOCKSIDE CIRCLE
		CITY:			WESTON
		STATE:			FL
		ZIP:			33327
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-06-22</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001304406</rptOwnerCik>
            <rptOwnerName>Glover Steve C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O INSMED INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>8720 STONY POINT PARKWAY, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>RICHMOND</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>23235</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President Follow-On Biologics</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.01</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2007-06-21</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-03-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By ZyVer &amp;  Associates</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.72</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-06-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>250000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option was granted to ZyVer &amp;  Associates of which the reporting person is the President and CEO.  ZyVer &amp;  Associates is wholly owned by the reporting person.</footnote>
        <footnote id="F2">The option will vest annually over a four year period with 62,500 shares vesting on each of June 22, 2008; June 22, 2009; June 22, 2010; and June 22, 2011.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Steve Glover</signatureName>
        <signatureDate>2007-06-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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