FYL (Fentanyl)
Fentanyl is a very strong opioid, prescribed as patches or lozenges but also common in illicit pills and powders.
Detection window: Usually detectable in urine for 1-3 days after use.
Prescriptions: A valid fentanyl prescription can cause a positive; the MRO review accounts for this on lab-confirmed tests.
How Testr tests for it
This panel is part of every Testr visit. A certified collector observes the collection at your home, checks specimen temperature, and reads a clinical 13-panel cassette on the spot. For measured levels rather than a positive/negative read, add laboratory confirmation: a certified lab quantifies the result and an independent Medical Review Officer reviews it before release.