-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 1lXd5zLOzBFGmqMGS+eYyg==

<SEC-DOCUMENT>0000904454-09-000678.txt : 20091112
<SEC-HEADER>0000904454-09-000678.hdr.sgml : 20091111
<ACCEPTANCE-DATETIME>20091112162904
ACCESSION NUMBER:		0000904454-09-000678
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091110
FILED AS OF DATE:		20091112
DATE AS OF CHANGE:		20091112

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DP VII ASSOCIATES LP
		CENTRAL INDEX KEY:			0001372932

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33415
		FILM NUMBER:		091177438

	BUSINESS ADDRESS:	
		STREET 1:		ONE PALMER SQ
		STREET 2:		STE 515
		CITY:			PRINCETON
		STATE:			NJ
		ZIP:			08542

	MAIL ADDRESS:	
		STREET 1:		ONE PALMER SQ
		STREET 2:		STE 515
		CITY:			PRINCETON
		STATE:			NJ
		ZIP:			08542

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Orexigen Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001382911
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				651178822
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3344 N. TORREY PINES CT.
		STREET 2:		SUITE 200
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037
		BUSINESS PHONE:		(858) 875-8600

	MAIL ADDRESS:	
		STREET 1:		3344 N. TORREY PINES CT.
		STREET 2:		SUITE 200
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-11-10</periodOfReport>

    <issuer>
        <issuerCik>0001382911</issuerCik>
        <issuerName>Orexigen Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>OREX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001372932</rptOwnerCik>
            <rptOwnerName>DP VII ASSOCIATES LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DOMAIN ASSOCIATES, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE PALMER SQUARE</rptOwnerStreet2>
            <rptOwnerCity>PRINCETON</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08542</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-11-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1415</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.93</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30959</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-11-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>899</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.93</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>31858</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kathleen K. Schoemaker, Managing Member of One Palmer Square Associates VII, LLC, General Partner of DP VII Associates, L.P.</signatureName>
        <signatureDate>2009-11-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----