The purpose of this study is to characterize the absorption, metabolism and routes of excretion of RE104 and its metabolites in healthy volunteers. This study will quantify drug and metabolites in blood, urine, and feces samples collected before study drug administration and through at least 168 hours after SC dosing of [14C]-RE104.

Inclusion Criteria:

• Between 18 and 55 years of age (inclusive), and a body mass index of 18-34 kg/m2.
• Willing to take a drug with psychoactive properties
• If female and of childbearing potential, agrees to use an acceptable method of birth control and is not planning to become pregnant before, during or within 90 days after the last dose of the study drug.
• If male, must agree to use condom with spermicide during and up to 90 days after discharge."
• Must agree to refrain from sperm or egg donation until 120 days post discharge.
• Able to understand and adhere to study schedule and requirements and willing to sign an ICF
• In good general health as determined by medical history, clinical laboratory test results, vital sign measurements, 12-lead ECG results, and physical examination findings at screening
• Agrees to not participate in other research studies involving investigational medication or medical devices for the duration of the study

Exclusion Criteria:

• Active or medical history of bipolar disorder, schizophrenia, schizoaffective disorder, psychotic disorder and/or borderline personality disorder, or first-degree family history of psychosis or bipolar disorder.
• Medical condition or other concomitant condition or history rendering unsuitability for the study
• Has used or intends to use prohibited medications
• Has a known sensitivity or intolerance to hallucinogenic or psychedelic substances, or potential rescue medications
• Has participated in another clinical study within 30 days and/or with a [14C] labeled study drug within 1 year prior to enrolling.
• Is pregnant or has a female partner who is pregnant