Interior Health issued a drug alert for Penticton on Wednesday.
The drug is described as grey pebbles sold as down/fentanyl containing a high percentage of fentanyl and a fentanyl analogue.
IH warns there is a high risk of overdose associated with the drug.
People are advised to always check their drugs before using, either through take-home fentanyl testing strips or accessing drug-checking technicians in their area.
The alert is in place until Feb. 1.