I applied essential oil topically over my abdomen yesterday, do I need to wait to take the test now?

If you've recently applied essential oil on your skin or in your belly button, it won't affect your test results.

Topical application of essential oil most likely won't affect your microbiome or the results of a Gut Health Test in any way.

You do need to wait 4 weeks since your last oral dose of anti-microbials, though.