Health supplements retailer GNC Holdings Inc. reported weaker-than-expected quarterly results, hurt by heavy promotions during the holiday shopping period.

GNC's shares fell as much as 15 percent after the bell.

The company also said it expected to earn about $3.18-$3.24 per share for the full year, well below the average analyst estimate of $3.46, according to Thomson Reuters I/B/E/S.

GNC, which also sells its products through GNC.com and Luckyvitamin.com, reported adjusted earnings of $60.6 million, or 63 cents per share, for the fourth quarter ended Dec. 31.

Revenue rose 8.6 percent to $613.7 million while same-store sales rose 5 percent.

Analysts on average had expected earnings of 64 cents per share on revenue of $631.5 million, according to Thomson Reuters I/B/E/S.

GNC's shares closed at $52.39 on the New York Stock Exchange on Thursday.