No. You can not overdose on GcMAFplus® – it is a naturally produced protein in healthy humans. In rare cases with high doses, some people experience mild detox-like symptoms such as a runny nose, fatigue, nausea and lethargy as the immune system re-balances to the influx of new GcMAF. If this happens you may wish to stop using the products for 2-3 days until the symptoms reside and begin use again.