This is how to use a simple home measurement to expose the harmful effects of a supplement before they even happen. Read the article here: https://chrismasterjohnphd.substack.com/p/the-dark-side-of-biotin Subscribe to my newsletter to get my series on improving respiratory chain function as soon as new articles come out: https://chrismasterjohnphd.substack.com/subscribe  See the "super unlock" article here: https://chrismasterjohnphd.substack.com/p/unlocking-performance-and-longevity