Exhibit 99.1

Zynex Announces First Quarter 2013 Financial Results

LONE TREE, Colo. – May 8, 2013—Zynex, Inc. (OTCQB: ZYXI), a provider and developer of non-invasive medical devices for electrotherapy and stroke rehabilitation, neurological diagnosis and cardiac monitoring, announces its first quarter 2013 financial results.

The Company’s net revenue decreased 14% to $7,668,000 for the three months ended March 31, 2013 from $8,944,000 for the three months ended March 31, 2012. The Company’s first quarter revenue was driven primarily by its Zynex Medical, electrotherapy subsidiary.

The Company reported a gross profit of $5,477,000, or 71% of net revenue, for the first three months of 2013, as compared to a gross profit of $7,131,000, or 80% of net revenue, for the first three months of 2012. The decrease in the Company’s first quarter 2013 gross profit percentage, as compared to the comparable period in 2012, was primarily a result of the lower sales volume for the period, as the Company had less net revenue to cover fixed manufacturing costs.

The Company reported Selling, General and Administrative (SG&A) expenses of $5,833,000, or 76% of net revenue for the first quarter of 2013, as compared to $6,645,000, or 74% of net revenue for the first quarter of 2012. Decreases in the Company’s SG&A expenses during the first quarter of 2013 as compared to the comparable period in 2012, were primarily attributable to reductions in sales and marketing expenses (related to lower sales commissions based on the decrease in net revenue and headcount reductions). The Company reduced SG&A expenses by $1,199,000, or 17% during first quarter of 2013, as compared to the fourth quarter of 2012, as a result of an ongoing effort to reduce expenses. The Company generated a first quarter 2013 loss from operations of $356,000, loss before income taxes of $492,000 and net loss attributable to Zynex, Inc. of $304,000, or $0.01 net loss per share, versus a first quarter 2012 income from operations of $486,000, income before income taxes of $393,000 and net income of $320,000, or $0.01 net income per share.

Thomas Sandgaard, CEO stated: “During the first quarter of 2013, we encountered industry challenges, specifically related to health care reform and business seasonality that affected demand in our core business, Zynex Medical. We believe uncertainty exists at the medical practitioner level related to changes in health care, which have delayed orders for our Zynex Medical business. In an effort to minimize the impact of these challenges, we made modifications to our direct sales force within our Zynex Medical business, including reducing the number of non-performing sales employees, modifying sales compensation packages and increasing the level of sales force training as it relates to health care reform. These efforts helped to reduce our overall selling, general and administrative costs for the first quarter of 2013 (resulting in a $1,199,000 expense savings over the fourth quarter of 2012), but also impacted the amount of orders that were received, contributing to a decrease in net revenue for the period. The first quarter of every year also presents a high degree of seasonality due to insurance ‘resets’ of patient deductibles, which tends to slow reimbursement and orders for our Zynex Medical business. We believe the impact from these changes is short-term and that our overall position in the electrotherapy market remains strong.”

Thomas Sandgaard, CEO added: “We continue investing in our other divisions, which are capital goods and service based where revenues are much less dependent on insurance reimbursement. In Zynex NeuroDiagnostics, we began aggressively expanding our sales force and recently entered into a sales and marketing agreement with NeuroVirtual, which allows Zynex NeuroDiagnostics to distribute electroencephalography (EEG) and sleep diagnostic products in the US. In the Zynex Monitoring division, our blood volume monitoring device is making good progress in clinical trials, and pending regulatory approval, a late 2013 release is possible. We are also making investments in the Zynex Billing and Consulting division where we expect incremental “service based” revenue going forward. Thus, we believe our investments in these new divisions serve to diversify our product mix and further reduce our dependency on insurance reimbursement, with the end goal of delivering steady revenue and profit growth for the years ahead.”

Outlook:

The Company anticipates net revenues of between $38 million and $42 million for 2013 and net income per diluted share of between $0.04 and $0.08 for 2013.

Conference Call and Webcast Information:

Zynex, Inc. will host a conference call and webcast at 9:00 a.m. MST (11:00 a.m. EST) today to discuss its first quarter 2013 results. Please note questions can only be submitted via the webcast user interface. Parties without access to the internet may join the presentation in listen only mode by dialing the toll free number provided below.

Webcast Information- http://www.visualwebcaster.com/event.asp?id=93823

Conference Call Information- 888-427-9411, pass-code 7209512

Highlights from the quarter ended March 31, 2013 consolidated financial statements:

(unaudited, amounts in thousands, except per share amounts)

About Zynex

Zynex (founded in 1996), operates under three primary business segments; Zynex Medical, Zynex NeuroDiagnostics and Zynex Monitoring Solutions. Zynex Medical engineers, manufactures, markets and sells its own design of electrotherapy medical devices for electrotherapy, used for pain management and rehabilitation. Zynex Medical’s product lines are fully developed, FDA-cleared and commercially sold world-wide. Zynex NeuroDiagnostics, sells the company’s proprietary NeuroMove device designed to help stroke and spinal cord injury patients and is currently expanding into markets for EMG, EEG, sleep pattern, auditory and nerve conductivity neurological diagnosis devices through product development and acquisitions. Zynex Monitoring Solutions, currently in the development stage, was established to develop and market medical devices for non-invasive cardiac monitoring.

For additional information, please visit: http://www.ir-site.com/zynex/default.asp.

Safe Harbor Statement

Certain statements in this release are “forward-looking” and as such are subject to numerous risks and uncertainties. Actual results may vary significantly from the results expressed or implied in such statements. Factors that could cause actual results to materially differ from forward-looking statements include, but are not limited to, the need to obtain additional capital in order to grow our business, our ability to engage additional sales representatives, the success of such additional sales representatives, the need to obtain FDA clearance and CE marking of new products, the acceptance of new products as well as existing products by doctors and hospitals, larger competitors with greater financial resources, the need to keep pace with technological changes, our dependence on the reimbursement from insurance companies for products sold or rented to our customers, acceptance of our products by health insurance providers, our dependence on third party manufacturers to produce our goods on time and to our specifications, implementation of our sales strategy including a strong direct sales force, the uncertain outcome of pending material litigation and other risks described in our filings with the Securities and Exchange Commission including the “Risk Factors” section of our Annual Report on Form 10-K for the year ended December 31, 2012.

Contact: Zynex, Inc. Anthony Scalese, CFO, 303-703-4906

ZYNEX, INC.

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CONSOLIDATED STATEMENT OF OPERATIONS

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