PITTSBURGH — GNC Holdings Inc. has reached an agreement with the New York attorney general that restores the full assortment of its Herbal Plus products to all stores in the state.

Some of GNC’s Herbal Plus products were part of an investigation of herbal supplements by New York Attorney General Eric Schneiderman, who in early February asked Walgreens, Walmart, Target and GNC to stop selling certain store-brand supplements because DNA testing revealed discrepancies with ingredients listed on their labels. Schneiderman sent cease-and-desist letters to the retailers to halt sales of the supplements in New York because they couldn’t be verified to contain the labeled substance or were found to contain ingredients not listed on the labels.

GNC said Monday that agreement with the New York attorney general affirms that the GNC products in question were in full compliance with Food and Drug Administration Current Good Manufacturing Practices and acknowledges GNC’s full cooperation with the attorney general’s inquiries.

In its response to the New York inquiry, and as highlighted in the agreement, GNC noted that it provided the results of rigorous tests conducted internally and by third parties. The company said the tests “provided conclusive evidence” that GNC products are safe, pure, properly labeled and in full compliance with all regulatory requirements and contain all herbal extracts listed on their labels.

In addition, GNC said a former senior FDA GMP expert performed a review of the company’s manufacturing processes for the products at issue and found them to be in compliance with all applicable requirements.

“As our testing demonstrated, and this agreement affirms beyond any doubt, our products are not only safe and pure but are in full compliance with all regulatory requirements,” GNC chief executive officer Michael Archbold said in a statement. “A robust testing regime, careful sourcing regimen and detailed manufacturing specifications have always been core elements to ensuring that we provide our customers with high quality products. Our customers trust and value our products, and we are steadfastly committed to maintaining that trust and confidence. As an industry leader we have always gone above and beyond the minimum requirements in pursuing quality for our consumers, and we will continue to lead the efforts for higher standards. This is good for consumers, good for the industry and good for GNC.”

GNC added that it will expand its testing processes deeper into its supply chain by leading industry efforts to integrate source material traceability standards — including DNA barcoding where appropriate (prior to extraction processes) — and enhance other aspects of its operations to provide consumers with greater confidence in its products.

Overall, GNC has more than 6,600 retail locations in the United States, including 1,070 franchise stores and 2,269 store-within-a-store outlets in Rite Aid drug stores.

Along with GNC’s Herbal Plus, the store brands at issue in the New York attorney general’s investigation were Walgreens’ Finest Nutrition, Walmart’s Spring Valley and Target’s Up & Up. DNA barcode tests were performed on six herbal supplements — gingko biloba, St. John’s wort, ginseng, garlic, echinacea and saw palmetto — purchased at some of the chains’ New York stores.

In late February, the New York investigation was expanded, as Schneiderman’s office sent letters to four supplement manufacturers — Pharmavite LLC, Nature’s Way Products Inc., NBTY Inc. and Nutraceutical Corp. — seeking information on the ingredients and quality control measures used for their products.

Supplement industry stakeholders have criticized the investigation, in particular its reliance on DNA barcode testing, which they called an unreliable and limited method for testing the identity of herbal dietary supplements.

“The agreement announced today between the New York attorney general and GNC performs a real disservice to consumers because it wrongly perpetuates the misdirected notion that DNA barcode testing is appropriate for herbal supplements, when it is not,” Steve Mister, president and chief executive officer of the Council for Responsible Nutrition (CRN), a dietary supplement industry trade association, said in a statement. “Moreover, the agreement gives credence to the New York AG’s misguided allegations based on its own DNA barcode testing that legitimate quality concerns existed about the products marketed by four retailers, when there were none. DNA barcode testing remains a flawed method for across-the-board testing for analyzing the quality of botanical ingredients and finished products.”

*Editor’s Note: Article updated with comment from CRN.