The U.S. Food and Drug Administration's recent enforcement action against drug promotion is sending ETFs with exposure to weight-loss treatment manufacturers into question.

On Sept. 9, the agency sent warning letters to Eli Lilly And Co (LLY  ), Novo Nordisk A/S (NVO  ), and Hims & Hers Health, Inc (HIMS  ) for what it perceives to be exaggerating the advantages of their GLP-1 weight-loss medications and underestimating severe threats.

The FDA indicated Eli Lilly and Novo Nordisk officials discussed therapies such as Mounjaro, Zepbound and Wegovy during media appearances, including a 2024 Oprah Winfrey special, but did not properly disclose boxed warnings and safety concerns. Hims & Hers was charged with "false or misleading" marketing claims on its website about compounded semaglutide products, which regulators stressed are not FDA-approved. The three companies have 15 working days to reply.

The news has drawn attention to the regulatory risks for ETFs focused on the weight-loss drug theme. The Amplify Weight Loss Drug & Treatment ETF (THNR  ) is invested in all three stocks, with Eli Lilly and Novo Nordisk two of its largest holdings and Hims & Hers as a smaller part. Any prolonged regulatory attention would be a drag on performance if sentiment around the GLP-1 drug space turns.

The Global X HealthTech ETF (HEAL  ), targeting digital and telehealth-service companies, also holds Hims & Hers. In the same vein, the Invesco Dorsey Wright Healthcare Momentum ETF (PTH  ) has exposure to Hims & Hers as part of other health care stocks that are momentum-based. Both funds might be indirectly pressured if regulatory issues reduce the popularity of obesity treatment based on telehealth.

Beneath the warning, Eli Lilly and Novo Nordisk are still market leaders in the sector, and their 2025 share gains have lifted health care ETFs overall. The FDA's increased monitoring, however, highlights headline-driven volatility risk, especially for thematic funds heavily exposed to weight-loss medication.

For investors, the recent crackdown acts as a reminder that although ETFs provide diversification, sector-specific funds such as THNR, HEAL, and PTH are still vulnerable to regulatory news surrounding the obesity drug bubble.