What happens if you mix marijuana with other drugs?
When marijuana is mixed with other drugs, it can increase the risk of adverse effects.
Mixing means using marijuana with other substances to change or enhance the experience. This can include alcohol, prescription drugs, stimulants, or opioids.
Mixing marijuana and alcohol can make the effects of both stronger. This can cause dizziness, poor coordination, and vomiting.
Using marijuana with prescription drugs, such as sedatives or anti-anxiety meds, can alter how those medicines work. It may also boost side effects, like making you feel drowsy.
Mixing marijuana with stimulants like cocaine or methamphetamine can lead to anxiety, paranoia, or confusion.
Some people may use marijuana in combination with prescription or street opioids for pain relief, but this can be risky. High doses of opioids (like heroin or fentanyl) can slow down breathing and increase the risk of overdose. (Stories of fentanyl-adulterated marijuana have not yet been confirmed with forensic testing. Smoking marijuana with a direct flame would destroy fentanyl. Consuming marijuana from a licensed dispensary reduces the risk of any contaminants or adulterants in the product.)
Lacing occurs when other drugs or chemicals are added to marijuana. This can happen with or without the user knowing. It can include drugs like PCP, heroin, cocaine, methamphetamine, and LSD. When marijuana is laced with other drugs, it can increase the risk of adverse effects. . Fentanyl is more likely to be found mixed with drugs like heroin and pills. However, it rarely appears in marijuana. This is because fentanyl doesn’t mix well with it, and smoking would destroy the fentanyl.
Reviewed and updated by Dr. Sheila P. Vakharia on 08/01/2025.