Can You Take Green Tea Extract (EGCG) and Vitamin B3 Together?

Use extra care with this pair

The short answer

Both high-dose EGCG and high-dose Niacin (B3) are hepatotoxic. EGCG causes oxidative hepatocellular injury, while sustained-release niacin causes dose-dependent liver damage. Combined use may compound hepatotoxic effects.

How to arrange timing

If combining, use the lowest effective doses. Choose immediate-release niacin and standard-dose green tea extract. Monitor liver function periodically.

Reference

Reference noted for this combination: Navarro VJ et al., Hepatology 2017; Guyton JR, Am J Cardiol 1998; LiverTox (NIH/NLM)

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.