Which of the following is a major issue with supplement manufacturers' self-regulation?

Inconsistent potency of supplements is a significant issue in the industry of dietary supplements due to the lack of stringent regulation. Unlike pharmaceuticals, which require extensive testing and must meet specific standards for efficacy and safety before they can be marketed, dietary supplements do not undergo the same rigorous review processes by the FDA.

This means that manufacturers may not be held to uniform standards for the concentration and potency of active ingredients in their products. As a result, different batches of the same supplement can vary widely in their actual content, leading to questions about their effectiveness and safety. Consumers may not receive the doses they expect, which can impact overall health outcomes and make it challenging for health professionals to recommend certain products reliably.

The other options involve processes that do not accurately reflect the current operational landscape for supplement manufacturers. There is no mandatory FDA review for all supplements, nor is there a requirement for scientific studies before marketing. Standardized ingredient sourcing, while beneficial, is not universally applied across all manufacturers, further contributing to the inconsistency in potency. Thus, the variability in supplement potency presents a noteworthy challenge in ensuring consumer safety and efficacy.