In post-market trading, shares had taken off 15.1% to $52.39.
Over fiscal 2013, the health and wellness retailer reported revenue of $2.63 billion, 8.2% higher than 2012. However, sales fell short of expectations for $2.65 billion, according to analysts surveyed by Thomson Reuters.
Full-year net income of $2.85 a share was 2 cents under consensus.
In the three months to December, revenue of $613.7 million came in 8.6% higher on the year-ago quarter, but missed expectations by around $18 million.
The Pittsburgh-based business saw same-store sales increase 5% in domestic company-owned stores over the fourth quarter, the company's thirty-fourth consecutive quarter of growth.
Net income of 63 cents a share was 26% higher than the year-ago quarter, but missed consensus by a penny.
"Despite the challenging retail environment, our business performed well, generating solid top- and bottom-line growth in the quarter," said CEO Joe Fortunato in a statement.
For fiscal 2014, management forecast earnings between $3.18 and $3.24 a share, below expectations of $3.46 a share.
A high-single-digit increase in revenue is expected over the full year.
"This is based on achieving a domestic company-owned same store sales result including the impact of GNC.com of flat for the first quarter of 2014 reflecting a very challenging January and February retail environment, and a mid-single-digit increase for the remainder of 2014," the company said in a statement.