'multiple substance' is correct and usable in written English.
You can use it when you're referring to more than one type of material. For example, "The scientists tested multiple substances in the laboratory."
The safe holds nothing but pristine keys, hundreds of them, one for every door at the $44 million building where Mr. Carney, 41, a multiple offender and multiple substance abuser in his angry-young-man 20s, became the primary caretaker — and first tenant — last summer.
Complex patterns of multiple substance use pose clinical and methodological challenges for substance abuse clinical trials research.
To examine differences in the characteristics and histories of male and female dependent heroin users, and in the clinical characteristics associated with multiple substance dependence diagnoses.
Multiple substance dependence categories together, rather than any one individual addiction outcome, may explain the genetic variability of such disorder.
The relationship with lower SOFAS scores persisted even when co-varying for multiple substance misuse.
UHR state was strongly associated with lower SOFAS scores, even when correcting for multiple substance misuse problems.
An older recurrent visitor, who abuses multiple substances, faces homelessness if the exasperated pastor who has looked after him refuses to take responsibility for his release.
They constitute variety without dissolving the infinite substance into multiple substances.
If there were multiple substantial forms there would be no unity to being human multiple substantial forms implies multiple substances and multiple beings.
Unknown multiple drug/alcohol toxicity includes cases where multiple substances were present but the coroner was unable to specifically identify which substances were responsible for death.
Aristotle recognized that most ordinary, material things are composed of multiple substances, although he thought that some of them could be composed of a single, pure substance.
