Mixing DayQuil and GHB / GBL (liquid G)
Dangerous
High risk of death or life-changing injury. Do not combine.
What to do
- Say what was taken and how much.Responders need it, and in most US states Good Samaritan laws protect both of you from drug possession charges when you call for an overdose.
- Unresponsive: put them on their side, tilt the head back, and stay until help arrives.Never leave someone alone to “sleep it off”.
- Never Use Alone 1-800-484-3731Stays on the line and sends help if you stop responding.
- Full steps: what to do if it is already happeningOverdose signs, the recovery position, what to say on the call, and whether you can be charged for making it.
- Poison Control 1-800-222-1222Free and 24/7, for “is this bad?” before it becomes an emergency.
Can you take DayQuil with GHB / GBL?
DayQuil contains acetaminophen and DXM. The most concerning part is DayQuil (DXM) with GHB / GBL: both wreck coordination and can cause vomiting and unconsciousness, and together they are hard to predict. Do not combine. If someone passes out, put them on their side. MixSafe rates DayQuil with GHB / GBL as "Dangerous" — high risk of death or life-changing injury. Do not combine. Sources: the Drug Facts labels on DailyMed, the TripSit combination chart and MixSafe research. Educational information, not medical advice.
What is in it
- DayQuil
- Acetaminophen + DXM. DayQuil also contains phenylephrine, a decongestant, and DayQuil Severe adds guaifenesin, an expectorant. MixSafe has no data for either.
Ingredient by ingredient
DayQuil (DXM) + GHB / GBLDangerous
Both wreck coordination and can cause vomiting and unconsciousness, and together they are hard to predict. Do not combine. If someone passes out, put them on their side.
Both substances cause ataxia and bring a risk of vomiting and unconsciousness. If the individual falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position. This combination is hard to predict
Source: TripSit drug combination chart
DayQuil (Acetaminophen) + GHB / GBLLow risk, no synergy
Neither substance is expected to meaningfully change the other. Both still carry their own individual risks.
No specific interaction is documented. Acetaminophen's main risk is dose-dependent liver injury, so the thing to watch in any combination is total daily intake across all products (roughly 4g/24h) and anything else straining the liver.
Sources: Prescott LF. Paracetamol, alcohol and the liver. Br J Clin Pharmacol. 2000 · Acetaminophen: A Liver Killer or Thriller
- Vicks DayQuil Cold & Flu LiquiCaps, Drug Facts label. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=efb982d4-93d0-815f-e053-2995a90a82dd
Ingredient lists checked 2026-09-27. Formulas change and store brands differ, so the Drug Facts box on your own packet is the final word.
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