My urine looks very dark. Should I wait and drink more water before collecting?

Dark urine indicates concentrated urine — you are mildly dehydrated. While the HL normalization handles concentration differences, very concentrated urine (very dark yellow or amber) can contain elevated levels of breakdown products that could interfere with RNA extraction. We recommend drinking a glass or two of water, waiting 1–2 hours, and then collecting when your urine has returned to a pale yellow color (straw-colored to light yellow is ideal). Do not drink excessive water to force dilution — just normal hydration to reach a healthy urine color. Very pale or clear urine (over-hydration) is also not ideal but is acceptable.