April 2023

Interaction Checker: FAQs on Ratings and Updates

Our Interaction Checker remains our most widely used and asked about tool. We’ve noticed an uptick in questions about how individual interactions are rated and how often it’s updated. Here’s a quick review.

The interaction checker screens for interactions between conventional drugs and supplements, including multi-ingredient supplement products. Data is pulled from our Commercial Products database, making it easier to check between several products and drugs at once. Each interaction is rated Major, Moderate, or Minor to help users determine which are most clinically relevant. The ratings account for the severity of the interaction, how likely it is to occur, and the level of evidence available.

New evidence emerges on a regular basis, so ratings aren’t set in stone, and new interactions are frequently added. For example, an interaction between apple juice and Organic Anion-Transporting Polypeptide substrates (OATP) was recently upgraded from Moderate to Major, since there’s been an increase in evidence showing that this interaction is likely to occur. An interaction between lithium and apple juice was also added. It’s rated as moderate – since the available evidence is limited to one case report. We also recently overhauled our progesterone monograph to only discuss supplement products. Since progesterone supplements contain much lower quantities of progesterone than prescription products, we downgraded the interaction ratings accordingly.

Keep in mind that because we're a natural products database, the checker doesn't cover drug-drug interactions. It also doesn’t include supplement-supplement interactions, but these can be found within our individual monographs. We’ll continue to update you on any major rating changes or new and notable interactions. Give our checker a try, and review our evidence-based rating system to learn more.

The information in this brief report is intended for informational purposes only, and is meant to help users better understand health concerns. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions. Copyright © 2024 NatMed. Commercial distribution or reproduction prohibited. NatMed is the leading provider of high-quality, evidence-based, clinically-relevant information on natural medicine, dietary supplements, herbs, vitamins, minerals, functional foods, diets, complementary practices, CAM modalities, exercises and medical conditions. Monograph sections include interactions with herbs, drugs, foods and labs, contraindications, depletions, dosing, toxicology, adverse effects, pregnancy and lactation data, synonyms, safety and effectiveness.