Are GNC Brand Supplements Third-Party Tested? Understanding Quality Control

December 24, 2025 •

4 min read

Following a high-profile investigation by the New York State Attorney General in 2015, GNC significantly expanded its quality control and third-party testing protocols. This action led many consumers to question, 'Are GNC brand supplements third-party tested?' The answer reveals a complex process that combines internal and external verification.

Quick Summary

GNC brand supplements undergo a combination of internal and third-party testing to ensure quality, purity, and safety. Some products, particularly those in the Pro Performance line, feature specific third-party certifications like Informed Choice for banned substances, while the company also requires suppliers to meet accredited standards.

Key Points

Third-Party Testing: Many GNC products, especially those in the Pro Performance line, are third-party tested for banned substances by agencies like LGC Sciences.
Internal Quality Control: All GNC supplements are manufactured in facilities that adhere to the FDA's Current Good Manufacturing Practices (cGMPs), which include robust internal testing.
Supplier Standards: GNC requires its ingredient suppliers to have third-party certifications from accredited bodies such as USP or NSF.
Post-2015 Enhancements: Following a legal inquiry, GNC expanded its testing protocols to include DNA barcoding and allergen screening for greater transparency and accuracy.
Customer Assurance: GNC aims to communicate its quality standards clearly to consumers through on-label certifications and detailed website information.
Informed Choice: Look for the Informed Choice logo on GNC labels to identify products certified as free from banned substances.

GNC's Comprehensive Quality Assurance Process

GNC's approach to supplement quality is multifaceted, involving a combination of internal measures and external third-party verification. While not every single product might carry a third-party seal, the company has implemented a robust system in response to past industry scrutiny. Their process is designed to ensure that products are compliant with federal regulations and meet their own internal standards for safety, identity, and purity.

The Role of Internal Testing and cGMPs

Before any external testing occurs, GNC's own quality control team oversees the manufacturing process. The supplements are produced in facilities that follow the U.S. Food and Drug Administration's (FDA) Current Good Manufacturing Practices (cGMP), which are mandatory federal standards. This involves rigorous in-house testing at multiple stages, from raw material inspection to finished product analysis.

Supplier Qualification: GNC requires its ingredient suppliers to also operate in cGMP-compliant facilities, with certification from third-party bodies like the United States Pharmacopeia (USP) or National Science Foundation (NSF).
Post-Production Verification: Products are re-tested after production to ensure all label claims are met before they are distributed to stores.
Advanced Testing Methods: Following the 2015 inquiry, GNC committed to using advanced DNA barcoding technology to authenticate herbal ingredients, which was a significant step toward improving transparency and accuracy.

Third-Party Testing: When and How?

While internal testing provides a solid baseline, third-party testing offers an unbiased level of assurance. GNC uses independent laboratories to verify the quality of specific products, particularly those aimed at competitive athletes. This external validation is a crucial step for building consumer trust.

Athlete-Focused Certifications: Many GNC Pro Performance products are tested by LGC Sciences, which certifies them as 'Banned Substance Tested' under the Informed Choice program. This assures athletes that the product is free from over 200 substances prohibited in competitive sports.
Response to Industry Probes: During the New York Attorney General's investigation into herbal supplements, GNC proactively commissioned independent third-party labs to re-test its Herbal Plus line. These tests confirmed the products' safety, purity, and proper labeling.
Ensuring Purity and Potency: Beyond banned substances, these third-party tests verify that the product contains the ingredients listed on the label in the correct amounts and is not contaminated with heavy metals, pesticides, or other harmful adulterants.

Internal vs. External Testing: A Comparison

It is helpful to understand the different levels of quality assurance employed by supplement companies. The following table compares GNC's internal testing with its third-party verification practices.


Feature	GNC Internal Testing	GNC Third-Party Testing
Purpose	Ensures compliance with cGMPs and internal quality standards.	Provides independent verification of product claims and safety.
Conducted By	GNC's own quality control laboratories and its manufacturing partners.	Independent, accredited third-party organizations like LGC Sciences.
Frequency	Continuous and standard procedure for all products during manufacturing.	Applied to specific product lines, particularly those marketed to athletes.
Scope of Testing	Covers ingredient identity, strength, composition, and manufacturing quality.	Often focuses on specific issues like banned substances or label verification.
Certifications	Does not result in public-facing certification logos.	Leads to official seals like "Informed Choice - Banned Substance Tested".

How to Identify Third-Party Tested GNC Supplements

For consumers, it is vital to know how to identify products that have undergone third-party testing. GNC is transparent about which products receive this level of scrutiny, especially within its athletic performance lines.

Look for specific logos and labels:

Informed Choice: This logo indicates that a product has been tested for over 200 banned substances, a crucial detail for competitive athletes.
Banned Substance Tested: Many labels will explicitly state this, indicating that it has been verified by an external third-party agency.
Learn More Online: GNC's website and product pages often provide additional information about their testing protocols and certifications.

GNC's Commitment to Quality Control

Since facing public scrutiny, GNC has publicly reinforced its commitment to quality control and transparency. Their agreement with the New York Attorney General in 2015, which involved instituting more rigorous testing methods like DNA barcoding and allergen screening, marked a turning point. The company has used this incident as a catalyst to improve its quality assurance program, including more stringent requirements for its ingredient suppliers. This proactive approach aims to rebuild consumer confidence and demonstrate a long-term commitment to product safety.

Ultimately, when you purchase a GNC brand supplement, you are buying into a system that combines mandated internal manufacturing practices with specific, product-focused third-party testing. For those who require the highest level of assurance, such as professional athletes, the explicitly labeled third-party tested products offer the necessary confidence. For general wellness products, the cGMP-compliant manufacturing and internal testing procedures provide a foundation of safety and purity.

Conclusion

In summary, the question of whether GNC brand supplements are third-party tested is nuanced. While not every product undergoes this process, the brand's quality control includes a combination of internal testing and targeted third-party certifications, particularly for its Pro Performance line. GNC's commitment to quality was significantly enhanced after an industry investigation, leading to more rigorous protocols for both its own manufacturing and its suppliers. For consumers, checking for specific seals like "Informed Choice" and reviewing the company's online resources will provide the most accurate information regarding individual product testing. This comprehensive approach to quality ensures that GNC continues to be a major player in the supplement market, offering various levels of assurance to its diverse customer base. For additional information about supplement testing standards, consult the USP website.

Frequently Asked Questions

GNC’s Pro Performance line, particularly protein and creatine products, are frequently third-party tested for banned substances under programs like Informed Choice. The company also commissioned independent tests for its Herbal Plus line in the past.

This label indicates that a third-party agency, such as LGC Sciences, has tested the product for over 200 substances banned in competitive sports. It provides an extra layer of assurance for athletes.

Yes, as part of their comprehensive quality control and third-party testing procedures, GNC products are tested for contaminants like heavy metals and pesticides to ensure they meet safety and purity requirements.

The FDA does not approve dietary supplements before they are marketed. However, GNC's manufacturing facilities must follow the FDA's Current Good Manufacturing Practices (cGMPs) to ensure quality and safety.

The easiest way is to look for specific third-party seals like "Informed Choice" directly on the product label. GNC's official website also offers a product authentication page where you can verify purchases.

In response to the inquiry, GNC agreed to a more rigorous testing regimen, including the use of DNA barcoding to verify herbal ingredients and testing for eight major allergens.

Yes, third-party testing is voluntary and goes beyond the federally mandated cGMP regulations. Companies like GNC often use it as a way to provide additional quality assurance to consumers, particularly in niche markets like athletic performance.