Berberine is commonly promoted as a vitamin alternative to Metformin. Even if Berberine also has no impact on all-cause mortality (idk), I can anecdotally share that 500mg 30minutes before lunch considerably lessens my post lunch fatigue.

As for human growth hormone, this Huberman Labs podcast advises against taking it but also offers many natural ways you can boost it[0].

[0]https://www.youtube.com/watch?v=x7qbJeRxWGw