<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-11-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001088856</issuerCik>
        <issuerName>CORCEPT THERAPEUTICS INC</issuerName>
        <issuerTradingSymbol>CORT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001163156</rptOwnerCik>
            <rptOwnerName>ALTA BIOPHARMA PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198328</rptOwnerCik>
            <rptOwnerName>MARDUEL ALIX</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198323</rptOwnerCik>
            <rptOwnerName>DELEAGE JEAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>37TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198321</rptOwnerCik>
            <rptOwnerName>CHAMPSI FARAH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001163189</rptOwnerCik>
            <rptOwnerName>ALTA BIOPHARMA MANAGEMENT II LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001163157</rptOwnerCik>
            <rptOwnerName>ALTA EMBARCADERO BIOPHARMA PARTNERS II LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001276361</rptOwnerCik>
            <rptOwnerName>ALTA PARTNERS II INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE EMBARCADERO CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3700</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</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>2008-11-11</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>103519</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.45</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5146818</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-11-11</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1307</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.45</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>167798</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Fund</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Alta BioPharma Partners II, L.P. (&quot;ABPII&quot;) acquired an additional 103,519 shares of Common Stock and Alta Embarcadero BioPharma Partners II, LLC (&quot;AEBPII&quot;) acquired an additional 1,307 shares of Common Stock from the issuer pursuant to the Amendment to Registration Rights Agreement dated November 11, 2008 in full satisfaction of cash liquidated damages owed under the Registration Rights Agreement dated as of March 14, 2008.  The shares of Common Stock were valued at $1.45 per share, the closing market price of the Common Stock on the NASDAQ Capital Market on November 11, 2008.</footnote>
        <footnote id="F2">These securities are held of record by ABPII.  Alta BioPharma Management II, LLC (&quot;ABMII&quot;) is the General Partner of ABPII.  Jean Deleage, Alix Marduel, and Farah Champsi are managing directors and Edward Penhoet is a director of ABMII and they exercise shared voting and investment power with respect to the shares owned by ABPIII.  Each of the reporting persons disclaims beneficial ownership of such securities, except to the extend of his, her or its proportionate pecuniary interest therein.</footnote>
        <footnote id="F3">Mr. Edward Penhoet is a director of the Issuer and files separate reports pursuant to Section 16 of the Securities Exchange Act of 1934, as amended.</footnote>
        <footnote id="F4">These securities are held of record by AEBPII.  Alta Partners II, Inc. (&quot;APII&quot;) provides investment advisory services to ABPIII and AEBPIII.  Jean Deleage, Alix Marduel, and Farah Champsi are managers of AEBPIII and exercise shared voting and investment power over the shares held by AEBPII.  Each of the reporting persons disclaims beneficial ownership of all such shares except to the extent of his or her proportionate pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By Alta BioPharma Management II, LLC
By /s/ Jean Deleage, Managing Director</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Alix Marduel</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jean Deleage</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Farah Champsi</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jean Deleage, Managing Director</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jean Deleage, Manager</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jean Deleage, President</signatureName>
        <signatureDate>2008-11-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
