These are tablets that, when dissolved in water, release hydrogen gas. The speaker extols the virtues of hydrogen gas as a selective antioxidant and anti-inflammatory, and mentions a study showing positive effects in elderly individuals.
"The speaker, who is very enthusiastic about biohacking, describes H2Tab as his favorite biohack, costing only about a dollar a day, and directs listeners to drinkh2tab.com for more information and scientific studies."