Understanding the effects of herbal supplements on lab tests is important for accurate results. Herbal products can introduce variability in measurements by interacting with laboratory assays or affecting sample quality. This page highlights essential tips for accurate testing, including what to disclose, how timing matters, and safe steps to prevent interference. Disclosing all herbal supplement use is the first and most crucial step. Provide the exact product name, ingredients list, dosage, frequency, and the dates you started or stopped each item. Include other related products such as vitamins or mineral supplements, and bring the packaging or labeling when possible to help identify ingredients. This information helps clinicians interpret results correctly and decide whether retesting or adjustments are needed. Timing and testing preparation matter. Some tests may be more sensitive to recent intake of herbal products, so follow the lab’s or clinician’s pre-test instructions. If you are unsure, contact the testing center for guidance. In general, avoid starting new herbal products or changing dosages close to a scheduled test, and inform the provider about any changes in your regimen. Safe steps to prevent interference include keeping a simple log of all products you use, bringing all items to appointments, and adhering to any hold times or instructions provided by the clinician or lab. Check labeling for ingredients and, if possible, note lot numbers. If a test result seems unusual, discuss the possibility of interference with your healthcare professional and consider scheduling a repeat test after any recommended hold period.
