Boron is a dietary mineral which is claimed to increase testosterone when supplemented at doses higher than from food, but research is lacking. It might as a byproduct of its anti-inflammatory effects.

https://examine.com/supplements/boron/

Examine is one of the best sources of u nbiased research review of supplements.

Unfortunately, the research that is available just isn't good enough. Poor design. Lack of meta analysis to compare the design and results of previous research.

I think it's important to paint a full picture to readers. If evidence is vague and not very trustworthy, we need to communicate that.