A former fentanyl user describes the first time she took the illicit drug laced with xylazine as 'the scariest experience of my life'

• Xylazine is an animal tranquilizer that's been turning up in street drugs for nearly a decade.
• Elissa Tierney is a former user who said she deliberately sought out fentanyl mixed with xylazine.
• The first time she took the drug combo she woke up unable to see or hear and was gasping for breath.

Elissa Tierney said she had been using fentanyl for so long that she was no longer feeling the euphoric effects — just using to keep from experiencing withdrawals.

When she unknowingly took fentanyl with xylazine for the first time four years ago, she said she woke up gasping for breath, unable to see or hear.