Mixing DXM and DPH

Mixing DXM and DPH is unsafe and best avoided — TripSit rates this combination “Unsafe.” Low risk never means safe.

The combination is reported to reduce the side effects of each drug and potentiate many of the recreational effects. There is a significant risk of serotonin syndrome, increased delirium, CNS depression, cognitive inhibition, risk of physical injury, hyperthermia, mania, paranoia, and psychosis, especially at higher dosages. There is an additional concern of tachycardia, hypertension, and in extreme cases, heart failure. Diphenhydramine is reported to inhibit the CYP2D6 enzyme which can increase levels of DXM. Medical dosages are not reported to be a concern. Caution is strongly recommended with this combination.

DXM (also known as cough syrup, Robo) and DPH (also known as Benadryl).

What to do

• Avoid this combination — the safest choice is not to mix them.
• Start with much less than usual and go slow — you can always take more, never less.
• Never use alone. If you do, call 1-800-484-3731 (Never Use Alone) so someone can send help if you stop responding.

Open the interactive combination checker

Related combinations

• Mixing Opioids and DXM
• Mixing Benzodiazepines and DXM
• Mixing Alcohol and DXM
• Mixing Cocaine and DXM
• Mixing Amphetamines and DXM
• Mixing MDMA and DXM
• Mixing Cannabis and DXM
• Mixing Ketamine and DXM

This is educational information, not medical advice. "Low risk" never means "safe", and the potency of an unregulated supply is unknown.