The in-vitro caveat is the key issue here. The "100x" figure refers to inflammatory marker measurements in isolated mouse macrophage cell cultures, a setup where compounds are applied directly to cells at controlled concentrations. Oral supplementation involves digestion, absorption, metabolism, and distribution to tissues that make those in-vitro concentrations essentially unreachable.

Taking capsaicin and peppermint supplements together is unlikely to cause harm, but you're not replicating the study conditions. The in-vitro result is interesting as a mechanistic signal. It suggests a possible interaction pathway worth investigating, but it doesn't provide dosing guidance for humans.

This gap between study type and real-world applicability is exactly why I built vital-stack.com for supplement interactions in my database, I surface the study type and mechanism alongside the conclusion, so you can judge how much weight to give it.