3C-E

uncontrolled hypertension, recent myocardial infarction, heart failure, significant arrhythmias

Severe cardiovascular conditions including uncontrolled hypertension, recent myocardial infarction, heart failure, or significant arrhythmias. Serotonergic phenethylamine psychedelics produce sympathomimetic cardiovascular effects as documented by Luethi & Liechti (2020). No cardiovascular data specific to 3C-E exist.

epilepsy, seizure disorders

History of seizure disorders including epilepsy. Phenethylamine psychedelics may lower seizure threshold, particularly at higher doses, through increased cortical excitability mediated by 5-HT2A receptor activation on layer V pyramidal neurons. No seizure events have been specifically reported with 3C-E.

schizophrenia, schizoaffective disorder, psychosis NOS, family history of psychotic disorders

Personal or family history of psychotic disorders including schizophrenia, schizoaffective disorder, or psychosis NOS. 5-HT2A receptor agonists can trigger acute psychotic episodes in vulnerable individuals. The prolonged duration of 3C-E (8-12 hours) extends the window of vulnerability relative to shorter-acting psychedelics.

lithium therapy

Current use of lithium is an absolute contraindication. The combination of lithium with serotonergic psychedelics has been associated with seizure risk in case reports across the psychedelic class. This interaction is classified as dangerous for LSD and structurally related compounds.

pregnancy, breastfeeding

Pregnancy is an absolute contraindication due to complete absence of reproductive toxicity data. No teratogenicity or developmental toxicity studies have been performed for 3C-E or any compound in the 3C series. Standard precautionary exclusion applies.

MAOI therapy, ayahuasca use

Current use of monoamine oxidase inhibitors (MAOIs) including pharmaceutical MAOIs (phenelzine, tranylcypromine, moclobemide) and natural MAOIs (harmine, harmaline). Although 3C-E does not itself release monoamines (Matsumoto et al. 2014), MAOI co-administration could extend duration and intensify effects by slowing metabolic clearance of endogenous serotonin during 5-HT2A receptor activation.