-----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,
 HpV+YzDSyzM2vfQITyl+r6rZXED0e6axACqmRn8nRIiAibnYSB8BNqP9oywdALJK
 SP1g720RvTgCd44hRtWL/w==

<SEC-DOCUMENT>0001140361-11-010589.txt : 20110217
<SEC-HEADER>0001140361-11-010589.hdr.sgml : 20110217
<ACCEPTANCE-DATETIME>20110217195300
ACCESSION NUMBER:		0001140361-11-010589
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110215
FILED AS OF DATE:		20110217
DATE AS OF CHANGE:		20110217

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lappe Mark
		CENTRAL INDEX KEY:			0001366074

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50481
		FILM NUMBER:		11622352

	MAIL ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AEOLUS PHARMACEUTICALS, INC.
		CENTRAL INDEX KEY:			0001261734
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				561953785
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		26361 CROWN VALLEY PARKWAY, SUITE 150
		CITY:			MISSION VIEJO
		STATE:			CA
		ZIP:			92691
		BUSINESS PHONE:		9494819825

	MAIL ADDRESS:	
		STREET 1:		26361 CROWN VALLEY PARKWAY, SUITE 150
		CITY:			MISSION VIEJO
		STATE:			CA
		ZIP:			92691

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INCARA PHARMACEUTICALS CORP
		DATE OF NAME CHANGE:	20031205

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INCARA INC
		DATE OF NAME CHANGE:	20030828

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Efficacy Capital, Ltd.
		CENTRAL INDEX KEY:			0001350855

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50481
		FILM NUMBER:		11622353

	BUSINESS ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL, SUITE 100
		CITY:			SAN DEIGO
		STATE:			CA
		ZIP:			92130
		BUSINESS PHONE:		858-759-1499

	MAIL ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL, SUITE 100
		CITY:			SAN DEIGO
		STATE:			CA
		ZIP:			92130

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Efficacy Biotech Master Fund Ltd.
		CENTRAL INDEX KEY:			0001366070
		STATE OF INCORPORATION:			D0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50481
		FILM NUMBER:		11622349

	BUSINESS ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
		BUSINESS PHONE:		(858) 759-1499

	MAIL ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Efficacy Biotech Fund LTD
		CENTRAL INDEX KEY:			0001366071
		STATE OF INCORPORATION:			D0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50481
		FILM NUMBER:		11622351

	BUSINESS ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
		BUSINESS PHONE:		(858) 759-1499

	MAIL ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Efficacy Biotech Fund L.P.
		CENTRAL INDEX KEY:			0001366073
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50481
		FILM NUMBER:		11622350

	BUSINESS ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
		BUSINESS PHONE:		(858) 759-1499

	MAIL ADDRESS:	
		STREET 1:		11622 EL CAMINO REAL
		STREET 2:		SUITE 100
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-02-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001261734</issuerCik>
        <issuerName>AEOLUS PHARMACEUTICALS, INC.</issuerName>
        <issuerTradingSymbol>AOLS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001350855</rptOwnerCik>
            <rptOwnerName>Efficacy Capital, Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 EL CAMINO REAL, SUITE 100</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DEIGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001366074</rptOwnerCik>
            <rptOwnerName>Lappe Mark</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 EL CAMINO REAL</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001366071</rptOwnerCik>
            <rptOwnerName>Efficacy Biotech Fund LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 EL CAMINO REAL</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001366073</rptOwnerCik>
            <rptOwnerName>Efficacy Biotech Fund L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 EL CAMINO REAL</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001366070</rptOwnerCik>
            <rptOwnerName>Efficacy Biotech Master Fund Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 EL CAMINO REAL</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.95</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8399646</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>57600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.97</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8342046</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares are owned directly by Efficacy Biotech Master Fund Ltd.  The Reporting Company acts as an investment advisor with investment and voting discretion over portfolio investments.  The Reporting Company is an indirect beneficial owner of the reported securities.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Efficacy Capital, Ltd., by /s/ Mark Lappe, Managing Partner</signatureName>
        <signatureDate>2011-02-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Mark Lappe</signatureName>
        <signatureDate>2011-02-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Efficacy Biotech Fund L.P., By Efficacy Capital Ltd., Investment Manager, By /s/ Mark Lappe, Managing Partner</signatureName>
        <signatureDate>2011-02-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Efficacy Biotech Fund LTD, By Efficacy Capital Ltd., Investment Manager, By /s/ Mark Lappe, Managing Partner</signatureName>
        <signatureDate>2011-02-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Efficacy Biotech Master Fund Ltd., By Efficacy Capital Ltd., Investment Manager, By /s/ Mark Lappe, Managing Partner</signatureName>
        <signatureDate>2011-02-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----