There's a lot of evidence that he popularized NMN and helped build market demand for it only to later use some regulatory trickery to ensure that a company he's involved with is the only one who's licensed to sell it in the US. This behavior is hostile towards consumers and would only financially benefit him and related parties. It's been frowned upon in NMN circles.
It puts a bad taste in my mouth given the fact that Sinclair tries to brand himself as someone who puts the interests of humanity over his own.
In the video below Dr. Brad Stanfield discusses the controversy: