1,3-Butanediol

Lethal interactions

Combination	Type	Severity	Mechanisms	Confidence
GHB, Baclofen	Drug class	lethal	2	high
Ketamine, DXM, PCP	Drug class	lethal	2	medium
Opioids	Drug class	lethal	2	high

35 dangerous interactions recorded for this substance.

Condition	Severity	Note
Psychiatric
alcohol use disorder	relative	Individuals with alcohol use disorder have established neuroadaptive changes that produce cross-tolerance with 1,3-BD. Competitive ADH inhibition with concurrent ethanol makes effects unpredictable. While ketone supplementation may reduce alcohol craving (Li 2024, 2026), the CNS depressant and dependence-producing properties of 1,3-BD pose substitution risk.
Metabolic
diabetes mellitus	relative	1,3-Butanediol lowers blood glucose in humans (Tobin 1975). Individuals with diabetes mellitus or those taking blood glucose-lowering medications face additive hypoglycemic risk. Blood glucose monitoring is advised if 1,3-BD is consumed.
hypoglycemia susceptibility	absolute	Individuals with fasting hypoglycemia, reactive hypoglycemia, or glycogen storage disorders face significant risk from 1,3-BD's documented glucose-lowering properties. Avoidance is recommended.
Pregnancy & Breastfeeding
pregnancy	relative	No human pregnancy safety data have been published. A single rat study showed no adverse fetal outcomes, but this is insufficient to establish safety. Standard precautionary avoidance applies.
Other
concurrent CNS depressant use	relative	No 1,3-BD-specific interaction studies with other CNS depressants exist. Class-level additive CNS depression risk is inferred. Combination with benzodiazepines, opioids, or other sedatives increases risk of excessive sedation, respiratory depression, and loss of consciousness.