(Corrects the headline and first paragraph to clarify there was no statistical significance in meeting endpoints.)

Niagen Bioscience (NAGE) said Wednesday that a clinical trial showed that daily supplement of its patented nicotinamide riboside Niagen did not show "statistically significant differences" in meeting primary or secondary endpoints in patients with long COVID-19 relative to placebo groups.

The 58-participant placebo-controlled 24-week study showed that the supplement increased NAD+ co-enzyme levels up to 3.1-fold and improved functioning, fatigue, depression, and sleep quality, when compared to their baseline levels, in some individuals, the company said.

The study's inconclusive results were "likely due to the small sample size and high dropout rates," the company said.