Depends on the coercion.
Taking action against false advertising of medical benefits is and should be under the purview of qualified government agencies, and should be a private cause of action.
E.g., the FDA and FTC have jurisdiction over false claims in drug and food advertising [0-2]. This is an unqualified good thing. It would be a large net benefit to society if these are also extended beyond specific paid-for standard-format advertising claims but also persistent promotion of false and unsubstantiated claims by jucksters like Joe Rogan, whether or not it is the result of direct paid promotion or just as part of his self-promoting schtick to increase it popularity with contrary opinions, and without regard to the number of people he will literally kill with his bad advice.
If you want the libertarian version, then when Jack's relative takes bad advice from adverts or some on-air huckster, then he has a cause of action to sue (and of course must establish that the relative relied on that advice and died from following the advised course of action, and that Jack has suffered losses).
Yes, countering disinformation is a thorny problem, but resorting to First Amendment absolutism is intellectually lazy at best. It feels like having a nice solid black&white answer, but it is not, since the result of the answer is the destruction of society. Bigger challenges and higher complexity society require more complex answers (and NO, simple censorship isn't the answer either).
[0] https://www.fda.gov/drugs/office-prescription-drug-promotion... [1] https://www.fda.gov/drugs/prescription-drug-advertising/back... [2] https://www.ftc.gov/news-events/topics/truth-advertising
