The Everlywell Metabolism Test measures the levels of cortisol, free testosterone, and TSH in the body. Levels outside of the typical range may affect a person’s weight management, energy production, and other important bodily functions. Cortisol helps the body regulate metabolism, the immune system, and stress. Testosterone affects body fat, muscle tone, and hair growth. TSH looks at how effectively the thyroid functions. The thyroid affects weight management, energy levels, and heat or cold sensitivity.