1P-LSD

Uncontrolled hypertension, significant arrhythmias, or severe cardiovascular disease. LSD's autonomic effects at 100 µg are moderate and comparable to psilocybin but may be clinically significant in compromised cardiovascular systems.

Epilepsy or seizure disorders. Theoretical risk of lowered seizure threshold via serotonergic modulation. No published evidence of LSD-triggered seizures in epileptic patients, but caution is warranted.

Personal or family history of schizophrenia, schizoaffective disorder, or other psychotic spectrum disorders. LSD can trigger acute psychosis, prolonged psychotic episodes, or first-break psychosis in predisposed individuals.

Personal history of bipolar I or bipolar II disorder. Risk of triggering manic or mixed episodes. Family history of bipolar disorder is a relative contraindication.

Significant hepatic impairment may alter the rate and extent of 1P-LSD deacylation, producing unpredictable LSD exposure. No published data on 1P-LSD in hepatic impairment.

Pregnancy and lactation are absolute contraindications due to complete absence of safety data and theoretical risks including uterotonic effects (ergoline class) and potential effects on fetal serotonergic neurodevelopment.

Concurrent use of monoamine oxidase inhibitors (MAOIs) including pharmaceutical MAOIs and ayahuasca. Serotonin syndrome risk via combined serotonin accumulation and direct receptor agonism.

Concurrent tramadol use is contraindicated due to risk of serotonin toxicity. Tramadol is the opioid most commonly implicated in serotonin syndrome cases.

Concurrent lithium therapy. Community reports describe seizure-like episodes during combined LSD-lithium use. Primary published evidence is lacking but the reports are consistent enough to warrant caution.