<SEC-DOCUMENT>0001104659-19-010795.txt : 20190226
<SEC-HEADER>0001104659-19-010795.hdr.sgml : 20190226
<ACCEPTANCE-DATETIME>20190226192501
ACCESSION NUMBER:		0001104659-19-010795
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190222
FILED AS OF DATE:		20190226
DATE AS OF CHANGE:		20190226

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NEWHALL CHARLES W III
		CENTRAL INDEX KEY:			0001005544

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35518
		FILM NUMBER:		19635240

	MAIL ADDRESS:	
		STREET 1:		1119 ST PAUL ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SUPERNUS PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0001356576
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE

	BUSINESS ADDRESS:	
		STREET 1:		1550 E GUDE DR
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
		BUSINESS PHONE:		301-838-2500

	MAIL ADDRESS:	
		STREET 1:		1550 E GUDE DR
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-02-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001356576</issuerCik>
        <issuerName>SUPERNUS PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>SUPN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001005544</rptOwnerCik>
            <rptOwnerName>NEWHALL CHARLES W III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SUPERNUS PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1550 EAST GUDE DRIVE</rptOwnerStreet2>
            <rptOwnerCity>ROCKVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20850</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>92298</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>36.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-02-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12427</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2020-02-22</value>
            </exerciseDate>
            <expirationDate>
                <value>2029-02-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12427</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12427</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Gregory S. Patrick, as attorney-in-fact</signatureName>
        <signatureDate>2019-02-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
