Too much H2S will kill you. The best way to increase H2S is to take Taurine. Taurine by itself is a very important nutrient. It could also increase H2S effectively. Both Taurine and H2S levels go down with age.
Found a reference. Apparently H2S increases nitric oxide.
Boosting endogenous production of vasoprotective hydrogen sulfide via supplementation with taurine and N-acetylcysteine: a novel way to promote cardiovascular health
https://www.ncbi.nlm...les/PMC5471864/