Exhibit 99.1

Questcor Reports First Quarter 2012 Financial Results

-Net Sales Grew to $96.0M vs. $36.8M in Q1 2011-

-GAAP Net Income per Diluted Share Grew to $0.58 vs. $0.17 in Year Ago Period-

-Value of First Quarter paid NS Prescriptions Exceeds MS Value-

-Expansion of Both NS and MS Sales Forces Well Ahead of Schedule-

-Conference Call and Webcast Today at 4:30 p.m. ET, 1:30 p.m. PT-

ANAHEIM, Calif., April 24, 2012 – Questcor Pharmaceuticals, Inc. (NASDAQ: QCOR) today reported financial results for the first quarter ended March 31, 2012. Net sales for the first quarter were $96.0 million, reflecting expanded physician usage of H.P. Acthar^® Gel (Acthar) for treating serious, difficult-to- treat medical conditions. Net sales in the first quarter 2011 were $36.8 million.

GAAP net income for the first quarter of 2012 was $38.5 million or $0.58 per diluted common share. GAAP net income for the first quarter of 2011 was $11.2 million, or $0.17 per diluted common share. Non-GAAP net income for the quarter ended March 31, 2012 was $40.6 million or $0.61 per diluted common share excluding non-cash share-based compensation expense and depreciation and amortization expense. Non-GAAP net income for the year ago quarter was $12.8 million, or $0.20 per diluted common share. Questcor repurchased 798,285 shares of its common stock during the first quarter 2012, at an average price of $36.31 per share.

During the first quarter of 2012, Questcor shipped 4,111 vials of Acthar, compared to 2,010 vials in the year ago quarter. The Company’s quarterly vial shipments continue to be subject to significant variation due to the size and timing of individual orders received from Questcor’s distributor. The timing of when these orders are received and filled can significantly affect net sales and net income in any particular quarter. For example, on the last day of the first quarter of 2012, Questcor filled an order for 180 vials. This shipment favorably impacted net sales by approximately $4 million and earnings per share by approximately four cents for the period. Due to this final order in the quarter, first quarter-ending channel inventory appears to be higher than the level at the end of the fourth quarter of 2011, and higher than the range of channel inventory over the past several quarters. The Company believes that investors should consider the Company’s results over several quarters when analyzing the Company’s performance.

Acthar Label Information

The product label for Acthar includes 19 FDA-approved indications. Substantially all of the Company’s net sales currently result from Acthar prescriptions for the on-label indications of:

Questcor expects to initiate a commercial effort in rheumatology in late 2012, since Acthar is approved for the following rheumatology-related conditions:

“While our substantial NS commercial effort only began in the fourth quarter of 2011, the value of NS shipped prescriptions now exceeds that of MS,” said Don M. Bailey, President and CEO of Questcor. “This faster-than-expected NS growth drove us to further expand the NS commercial effort prior to the additional expansion of our MS commercial team. At the same time, we continue to increase our investment in efforts to learn about the possible therapeutic applications of Acthar in other inflammatory and autoimmune diseases as well as increase investments in our management systems, internal control, and compliance infrastructure.”

“The expansion of our Nephrology Sales Force from 28 to 58 representatives will be completed by early June, well ahead of our original schedule,” noted Steve Cartt, Chief Operating Officer. “In addition, we are also planning to add approximately 30 more representatives to our Neurology Sales Force, with hiring and training expected to be completed sometime in August. We believe these expansions will enable us to further broaden physician awareness of Acthar and its appropriate role in the treatment of both MS relapses and NS. Furthermore, we remain on track to initiate a pilot commercial effort in rheumatology by the end of this year.

“We have been expanding our scientific efforts and R&D investments in Acthar, and expect that we will continue to increase spending to support Questcor’s future growth,” commented Dr. David Young, Chief Scientific Officer. “Currently, we are funding more than 40 pre-clinical or clinical studies and we have increased our investigation into better understanding how Acthar works and its other potential applications.”

Shipped Acthar Vial and Prescription Trend Information

Because Acthar prescriptions are filled at specialty pharmacies, the Company does not receive complete information regarding either the number of prescriptions or the number of vials by therapeutic area for all of the patients being treated with Acthar. However, Questcor is able to monitor trends in payer mix and areas of therapeutic use for new Acthar prescriptions based on data it receives from its reimbursement support center. Questcor estimates that over 90% of new Acthar prescriptions are processed by this support center, but believes that very few refill prescriptions are processed there.

In an effort to help investors better understand historical trends in the prescriptions written for Acthar within each of its current three key therapeutic areas, NS, MS, and IS, Questcor is providing quarterly prescription information for the time period January 1 2010 through March 31, 2012. We grouped prescriptions processed by its reimbursement center into two groups – “Paid” and “Fully Rebated.”

“Paid” prescriptions (Rxs) include all prescriptions in the following payer categories:

“Fully Rebated” prescriptions (Rxs) include:

The following tables show, for each of the three key Acthar therapeutic uses, the number of new prescriptions shipped grouped into “Paid” and “Fully Rebated”:

Nephrotic Syndrome (and related conditions) New Rxs *

Multiple Sclerosis (and related conditions) New Rxs

Infantile Spasms (and related conditions) New Rxs**

Notes:

(1) Because the March 2010 health care legislation made Medicaid Managed Care Organization (MCO) prescriptions rebate eligible effective March 23, 2010, a rebate liability for the MCO prescriptions estimated to be filled on or after March 23, 2010 has been accrued. The Company does not have the ability to accurately identify every Medicaid Managed Care prescription so it is possible that some prescriptions identified as “Paid” in the tables may subsequently be reclassified as “Fully Rebated.”

(2) “Related Conditions” includes diagnoses that are either alternate descriptions of the medical condition or are closely related to the medical condition which is the focus of the table. For example, a prescription for “demyelinating disease of the central nervous system” would be included as an MS-related condition for purpose of this table. About 5% of the prescriptions in the tables are for related conditions.

(3) A prescription may or may not represent a new patient or a new therapy for the patient receiving the prescription. Questcor uses business rules to determine whether a prescription should be included in this table. From time to time the Company may modify these rules which could cause some changes to the historic numbers in the tables above.

(4) Historical trend information is not necessarily indicative of future results. Additionally, paid prescriptions should not be viewed as predictive of Questcor’s net sales due to a variety of factors, including changes in the number of vials used in connection with each prescription.

Cash and Share Repurchase Program

As of April 20, 2012, Questcor’s cash, cash equivalents and short-term investments totaled $248 million, and its accounts receivable totaled $37 million. The Company used $29.0 million in cash to repurchase 798,285 shares during the first quarter. As of March 31, 2012, Questcor had 63.0 million shares of common stock outstanding, with 3.5 million shares remaining under its common stock repurchase program.

Sales Reserves

Questcor’s sales reserves during the quarter ended March 31, 2012, including the Company’s reserves for Medicaid rebates, represented 14% of gross sales of $111.3 million.

As required by federal regulations, Questcor provides rebates to state Medicaid programs for Acthar dispensed to Medicaid patients covered under Medicaid rebate-eligible insurance plans. Since the Company does not receive rebate claims from the various state Medicaid agencies until well after the close of the quarter in which the underlying sales of vials to its distributor took place, the Company establishes reserves for expected rebate claims on a quarterly basis. As a result of the new Federal health care related legislation, for periods after March 23, 2010, the Company has also included in this reserve an estimate for the liability due to states related to prescriptions of Acthar for patients covered under state Medicaid Managed Care Organizations (Medicaid MCO), which prescriptions were not previously rebate eligible.

Questcor experienced a decrease in sales reserves as a percentage of gross sales during the first quarter of 2012, compared to the first quarter of 2011. The principal reasons for this decrease were (1) an increase in the percentage of total Acthar prescriptions written to treat adults suffering from MS and NS relative to the percentage used to treat infants suffering from IS, as there is a very high percentage of infants enrolled in Medicaid, and (2) an increase in the number of IS prescriptions being fulfilled through either the Acthar free drug program administered by the National Organization for Rare Disorders or the Company’s hospital sample vial program. Since September 2007, Questcor has provided free drug with a commercial value of over $150 million to patients through these programs.

Conference Call Details

The Company will host a conference call and slide presentation via webcast today, April 24, 2012, at 4:30 p.m. ET/ 1:30 p.m. PT, to discuss first quarter 2012 results.

To participate in the live call by telephone, please dial (877) 354-0215 for domestic participants and (253) 237-1173 for international participants. Participants are asked to call the above numbers 5-10 minutes prior to the start time. A listen-only webcast of the conference call including the presentation slides will be accessible in the “Investor Relations” section under “Events & Presentations” at http://ir.questcor.com/events.cfm. If listening via telephone, to view the accompanying presentation slides, navigate to the live webcast as noted above and choose the “No Audio – Slides Only” option to view the slides in conjunction with the live conference call. Listeners should go to the website at least 15 minutes prior to the live conference call to install any necessary software.

An audio replay of the call will be available for 30 days following the call. This replay can be accessed by dialing (855) 859-2056 for domestic callers and (404) 537-3406 for international callers, both using Conference ID # 70200329. An archived webcast will also be available at http://ir.questcor.com/events.cfm.

Use of Non-GAAP Net Income

The Company believes it is important to share non-GAAP financial metrics with shareholders as these metrics may better represent the ongoing economics of the business and reflect how we manage the business. Accordingly, management believes investors’ understanding of the Company’s financial performance is enhanced as a result of our disclosing these non-GAAP financial metrics. Non-GAAP net income should not be viewed in isolation, or as a substitute for, or as superior to, reported GAAP net income. The reconciliation between GAAP and Non-GAAP net income is provided with the financial tables included with this release.

About Questcor

Questcor Pharmaceuticals, Inc. is a biopharmaceutical company whose primary product helps patients with serious, difficult-to-treat medical conditions. Questcor’s primary product is H.P. Acthar^® Gel (repository corticotropin injection), an injectable drug that is approved by the FDA for the treatment of 19 indications. Of these 19 indications, Questcor currently generates substantially all of its net sales from three indications: the treatment of proteinuria in idiopathic types of nephrotic syndrome, the treatment of acute exacerbations of multiple sclerosis in adults, and the treatment of infantile spasms in children under two years of age. With respect to nephrotic syndrome, the FDA has approved Acthar to “induce a diuresis or a remission of proteinuria in the nephrotic syndrome without uremia of the idiopathic type or that due to lupus erythematosus.” Questcor is also currently planning to explore the potential initiation of a commercial effort in rheumatology, as Acthar is approved for several rheumatology-related conditions including Lupus, Dermatomyositis, Polymyositis and Rheumatoid Arthritis. Questcor is also exploring the possibility of developing markets for other on-label indications and the possibility of pursuing FDA approval of additional indications not currently on the Acthar label where there is high unmet medical need. For more information about Questcor, please visit www.questcor.com.

Note: Except for the historical information contained herein, this press release contains forward-looking statements that have been made pursuant to the Private Securities Litigation Reform Act of 1995. These statements relate to future events or our future financial performance. In some cases, you can identify forward-looking statements by terminology such as “believes,” “continue,” “could,” “estimates,” “expects,” “growth,” “may,” “plans,” “potential,” “should,” “substantial” or “will” or the negative of such terms

and other comparable terminology. These statements are only predictions. Actual events or results may differ materially. Factors that could cause or contribute to such differences include, but are not limited to, the following:

The risk factors and other information contained in these documents should be considered in evaluating Questcor’s prospects and future financial performance.

Questcor undertakes no obligation to publicly release the result of any revisions to these forward-looking statements, which may be made to reflect events or circumstances after the date of this release.

For more information, please visit www.questcor.com or www.acthar.com.

CONTACT INFORMATION:

Questcor Pharmaceuticals, Inc.

Don Bailey

714-786-4210

dbailey@Questcor.com

QUESTCOR PHARMACEUTICALS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME

(In thousands, except per share data)

(unaudited)

Net income per share – basic and diluted may not foot due to rounding.

Use of Non-GAAP Financial Measures

Our “non-GAAP adjusted net income” excludes the following items from GAAP net income:

Questcor Pharmaceuticals, Inc.

Consolidated Balance Sheets

(In thousands, except share amounts)

Questcor Pharmaceuticals, Inc.

Consolidated Statements of Cash Flows

(In thousands)

(unaudited)