Healthy VolunteersPhase 1NCT07079930
Safety and Psychological Effects of Psilocybin and D-Serine Formulation in Healthy Volunteers
A Phase 1 study testing Psilocybin and D-Serine, Physical Examination and Vital signs in people with Healthy Volunteers, run by Hadassah Medical Organization at 1 site in Israel.
Trial summary
The goal of this open-label, dose-escalation, prospective study is to evaluate the safety and psychological effects of a Psilocybin and D-Serine formulation in healthy volunteers. The main objectives are: 1. Read more about this study
- Who is it for?
- Ages 25 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Volunteers
- What is being tested?
- Psilocybin and D-Serine, Physical Examination and Vital signs
- Type of treatment
- Pill or oral medicine, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteIsrael
- Study dates
- 11 Dec 2025to Feb 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Aged 25-60 years, male or female.
- Medically healthy, as confirmed by a comprehensive clinical assessment.
- Written informed consent provided.
Who cannot join
- History of any Axis 1 psychiatric disorder requiring pharmacotherapy such as schizophrenia, schizoaffective disorder, any other psychotic disorder, bipolar disorder, as well as non-psychotic disorders such as generalized anxiety disorder, major depressive disorder, obsessive-compulsive disorder, posttraumatic stress disorder.
- Family history (among first-degree relatives) of schizophrenia, bipolar disorder, or other psychotic disorder
- History of cardiovascular disorders.
- Pregnant or breastfeeding women or women of childbearing age not using effective contraception.
- Use of psilocybin or other psychedelic compound in the 12 months preceding the study
- Use of medications that interact with psilocybin or D-Serine.
- Positive urinary drug screening.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Israel1 site, 1 recruiting
- Recruiting
Hadassah Medical Organization, Jerusalem, Israel
Jerusalem
Hadas Lemberg, PhD, 00 972 2 6777572, lhadas@hadassah.org.il
Bernard Lerer, MD
About this study
The goal of this open-label, dose-escalation, prospective study is to evaluate the safety and psychological effects of a Psilocybin and D-Serine formulation in healthy volunteers.
The main objectives are:
Read more
- To assess the psychological and physiological effects of psilocybin administered with D-Serine in healthy adults.
- To determine whether D-Serine modulates or attenuates the psychedelic effects of psilocybin.
- To evaluate the safety and tolerability of psilocybin and D-Serine co-administration.
Study population includes: 10 healthy male or female volunteers aged 25-60 years with no history of psychiatric or major medical disorders and no current evidence of such disorders.
The study includes two cohorts. The first cohort of 5 participants will receive 15 mg of Psilocybin and 5 g of D-Serine. Safety data will be collected and submitted in an interim report to the Ethics Committee. If no safety concerns arise, the second cohort will receive an increased dose of 25 mg of Psilocybin and 7 g of D-Serine to help determine the optimal dose for a future Phase IIa clinical trial.
Read the detailed description
This is a first-in-human, Phase I, exploratory clinical trial designed to evaluate the safety, tolerability, and initial psychological and physiological responses to a single administration of psilocybin in combination with D-Serine in healthy adult volunteers. The rationale for this combination stems from preclinical evidence indicating that D-Serine, a naturally occurring co-agonist at the NMDA receptor, may attenuate the acute psychedelic effects of psilocybin while preserving its neuroplastic and therapeutic properties.
Preclinical studies demonstrated that D-Serine reduced the psilocybin-induced head-twitch response (HTR) in rodent models and enhanced the expression of synaptic plasticity markers (e.g., GAP43, PSD95, SV2A, synaptophysin) across multiple brain regions, with effects sustained up to 12 days post-treatment. These findings suggest that the combination may improve the safety and tolerability of psilocybin, particularly for populations sensitive to its psychoactive effects.
The trial will consist of four sequential components:
Screening Phase - to assess eligibility.
Preparation Phase - to establish therapeutic rapport and baseline assessments.
Administration Phase - involving a single oral administration of the investigational combination (psilocybin + D-Serine).
Follow-up Phase - including in-person follow-up visits on Day 2, Day 7, Day 28, and Day 84 post-treatment to monitor safety outcomes, subjective responses, and potential delayed effects.
- Conditions
- Healthy Volunteers
- Being tested
- Psilocybin and D-Serine, Physical Examination, Vital signs, ECG test, Comprehensive Blood Panel
- Keywords
- psilocybin D-Serine healthy volunteers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Psilocybin and D-SerineDrug
A single administration of the drug, with dosage divided as follows:
Cohort 1: 15 mg of Psilocybin and 5 gr of D-Serine Cohort 2: 25 mg of Psilocybin and 7 gr of D-Serine
Physical ExaminationDiagnostic test
The physical examination will include diagnosis and documentation of any significant clinical abnormalities or diseases. It will be performed during the baseline rating visit (preparation phase).
Vital signsDiagnostic test
Vital sign measurements (blood pressure, pulse, and oxygen saturation) will be taken at screening, preparation, baseline rating, administration day, day 2, day 28, and day 84.
Vital signs will be assessed at the following time points on the administration day and on day 2: pre-administration, and at 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, and 24 hours post-administration.
ECG testDiagnostic test
A 12-lead ECG will be performed to rule out underlying cardiac abnormalities. An ECG will be conducted for each patient during the screening and Day 2 visits.
Comprehensive Blood PanelDiagnostic test
Also called SMAC-20
A comprehensive blood panel will be performed to assess kidney and liver function, electrolyte balance, and glucose levels.
It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84.
Complete Blood CountDiagnostic test
Also called CBC
Complete Blood Count will be performed to check for hematological abnormalities.
It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84.
UrinalysisDiagnostic test
Urinalysis will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84.
Urine Toxicology ScreenDiagnostic test
Urine Toxicology Screen will be performed to rule out illicit drug use. It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84.
A pregnancy Urine testDiagnostic test
A urine pregnancy test will be performed for women of childbearing potential only. It will be conducted during the screening and baseline rating visits. If the urine test is positive, a serum β-hCG test will be performed for confirmation.
ElectroencephalogramDiagnostic test
Also called EEG
EEG will be performed during the baseline rating scale and Day 7 visits to evaluate brain activity
Plasma Amino Acid LevelsDiagnostic test
The following blood test parameters - D-Serine, L-Serine, and Glycine - will be assessed during the Screening and Day 28 visits.
Plasma Inflammation MarkersDiagnostic test
The following blood test parameters - Tumor Necrosis Factor Alpha (TNF-α), Interleukin-6 (IL-6), and C-Reactive Protein (CRP) - will be assessed during the Screening and Day 28 visits.
Plasma Brain-Derived Neurotrophic FactoDiagnostic test
Also called Plasma BDNF
Plasma BDNF (Brain-Derived Neurotrophic Factor) levels will be measured during the screening and Day 28 visits.
Mini International Neuropsychiatric InterviewOther
Also called MINI
The Mini International Neuropsychiatric Interview (MINI) will be administered during the screening visit to rule out any current or past major psychiatric disorders.
Family Psychiatric History AssessmentOther
Also called FPHA
The Family Psychiatric History Assessment (FPHA) will be administered during the screening visit to help rule out any current or past major psychiatric disorders.
Beck Depression InventoryOther
Also called BDI
The Beck Depression Inventory (BDI) will be administered at the following visits: screening, baseline, day 7, day 28, and day 84. It will be used to assess baseline mood and to rule out depressive symptoms.
State-Trait Anxiety InventoryOther
Also called STAI
State-Trait Anxiety Inventory (STAI) will be administered at the following visits: screening, baseline, day 7, day 28, and day 84. It will be used to screen for anxiety disorders.
Profile of Mood StatesBehavioural
Also called POMS
The Profile of Mood States (POMS) will be administered to assess baseline mood and emotional state.
It will be administered at the following visits: screening, baseline, administration day, day 2, day 7, day 28, and day 84.
On the administration day and on day 2, it will be administered at the following time points: pre-administration, and 8 and 20 hours post-administration.
Subjective Units of Distress ScaleBehavioural
Also called SUDS
Subjective Units of Distress Scale (SUDS) will be administered to assess anxiety and stress levels.
It will be administered at the following visits: screening, baseline, administration day, day 2, day 7, day 28, and day 84.
On the administration day and on day 2, it will be administered at the following time points: pre-administration, and 8 and 20 hours post-administration.
Five-Dimensional Altered States of Consciousness questionnaireOther
Also called 5D-ASC
The Five-Dimensional Altered States of Consciousness questionnaire (5D-ASC) will be used to assess the acute subjective psychedelic experience. It will be administered after the acute effects have subsided - at 6.0 hours post-administration on the administration day, and again on day 2 - to evaluate five key experiential dimensions: visual restructuralization, oceanic boundlessness, reduction of vigilance, anxious ego dissolution, and auditory alterations. Each item will be rated using a Visual Analogue Scale (VAS) ranging from "NO, not more than usually" (0 mm) to "YES, much more than usually" (100 mm).
IntegrationBehavioural
The integration process is conducted to support participants in processing and incorporating their therapeutic experience into daily life, with the aim of enhancing emotional insight and psychological well-being. Integration will take place at the following visits: 8.0 hours post-treatment on the administration day, day 2, day 7, day 28, and day 84.
| Study group | Role | What they receive |
|---|---|---|
| 15 mg of Psilocybin and 5 gr of D-Serine | Experimental | The investigational drug, 15 mg of Psilocybin and 5 g of D-Serine, will be administered as a single oral dose in solution form. Receives: Drug: Psilocybin and D-Serine; Diagnostic Test: Physical Examination; Diagnostic Test: Vital signs; Diagnostic Test: ECG test; Diagnostic Test: Comprehensive Blood Panel; Diagnostic Test: Complete Blood Count; Diagnostic Test: Urinalysis; Diagnostic Test: Urine Toxicology Screen; Diagnostic Test: A pregnancy Urine test; Diagnostic Test: Electroencephalogram; Diagnostic Test: Plasma Amino Acid Levels; Diagnostic Test: Plasma Inflammation Markers; Diagnostic Test: Plasma Brain-Derived Neurotrophic Facto; Other: Mini International Neuropsychiatric Interview; Other: Family Psychiatric History Assessment; Other: Beck Depression Inventory; Other: State-Trait Anxiety Inventory; Behavioral: Profile of Mood States; Behavioral: Subjective Units of Distress Scale; Other: Five-Dimensional Altered States of Consciousness questionnaire; Behavioral: Integration |
| 25 mg of Psilocybin and 7 gr of D-Serine | Experimental | The investigational drug, 25 mg of Psilocybin and 7 g of D-Serine, will be administered as a single oral dose in solution form. Receives: Drug: Psilocybin and D-Serine; Diagnostic Test: Physical Examination; Diagnostic Test: Vital signs; Diagnostic Test: ECG test; Diagnostic Test: Comprehensive Blood Panel; Diagnostic Test: Complete Blood Count; Diagnostic Test: Urinalysis; Diagnostic Test: Urine Toxicology Screen; Diagnostic Test: A pregnancy Urine test; Diagnostic Test: Electroencephalogram; Diagnostic Test: Plasma Amino Acid Levels; Diagnostic Test: Plasma Inflammation Markers; Diagnostic Test: Plasma Brain-Derived Neurotrophic Facto; Other: Mini International Neuropsychiatric Interview; Other: Family Psychiatric History Assessment; Other: Beck Depression Inventory; Other: State-Trait Anxiety Inventory; Behavioral: Profile of Mood States; Behavioral: Subjective Units of Distress Scale; Other: Five-Dimensional Altered States of Consciousness questionnaire; Behavioral: Integration |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence and severity of treatment-emergent adverse events (TEAEs) following administration of psilocybin and D-serine
The number, type, severity, timing, and relatedness of treatment-emergent adverse events following administration of psilocybin and D-serine. Adverse events will be assessed through continuous clinical monitoring, spontaneous reports, and structured instruments including the UKU Side Effect Rating Scale. Safety will also be evaluated via changes in vital signs, ECG, and laboratory tests (SMAC-20, CBC, urinalysis). Events will be classified using standard regulatory definitions and graded for severity and relatedness to study treatment.
Measured: From time of dosing (Day 1) through Day 84 (final follow-up visit)
Secondary outcomes (9)
Change in subjective psychedelic experience measured by the 5D-ASC scale
Assessment of subjective altered states of consciousness using the 5-Dimensional Altered States of Consciousness scale.
Full questionnaire consists of 94 items, each item reflects a subjective experience during the altered state.
Each rated on a visual analog scale from 0 to 100, where:
0 = "not at all" 100 = "extremely"
The items are grouped into 5 empirically derived dimensions, each representing a core aspect of altered consciousness:
Oceanic Boundlessness- Positively experienced ego dissolution, unity, bliss High scores = mystical-type experiences Anxious Ego Dissolution- Anxiety, loss of ego control, cognitive impairment High scores = difficult or fearful experiences Visionary Restructuralization -Visual imagery, hallucinations, synesthesia High scores = complex visual phenomena Auditory Alterations - Changes in auditory perception, e.g., hearing sounds or voices Reduction of Vigilance- Reduced alertness or drowsiness (less relevant in classic psychedelic states)
Measured: 6 hours post-dosing and Day 2 follow-up
Change in mood states assessed by the Profile of Mood States (POMS)
Change in emotional and mood states as measured by the POMS scale. Participants complete the questionnaire at multiple time points to evaluate transient mood fluctuations in response to treatment.
The administered version of the POMS questionnaire consists of 28 adjectives describing various feelings and emotions, and participants rate the extent to which they have experienced each over a specified period (e.g., the past week), typically using a 5-point Likert scale ranging from 0 ("not at all") to 4 ("extremely").
Measured: Baseline, 8 and 20 hours post-dosing, Day 2, Week 1, and Day 84
Change in anxiety and stress measured by the Subjective Units of Distress Scale (SUDS)
Subjective assessment of distress and anxiety using the SUDS, a self-report scale ranging from 0 (no distress) to 100 (extreme distress). Assessed multiple times to track acute and residual anxiety responses.
Measured: Baseline, 8 and 20 hours post-dosing, Day 2
Change in plasma D-serine concentration
Measurement of plasma D-serine (in micromoles per liter (µmol/L)) to explore potential neurobiological correlates of treatment. Blood collected at baseline and follow-up.
Measured: Baseline and Week 1 (Day 7)
Change in plasma inflammatory markers concentration.
Measurement of plasma inflammatory markers to explore potential neurobiological correlates of treatment. Blood collected at baseline and follow-up.
Measured: Baseline and Week 1 (Day 7)
Change in plasma BDNF concentration
Measurement of plasma PLASMA Brain-Derived Neurotrophic Factor (in micromoles per picograms per milliliter (pg/mL)) to explore potential neurobiological correlates of treatment. Blood collected at baseline and follow-up.
Measured: Baseline and Week 1 (Day 7)
Change in plasma glutamate concentration
Measurement of plasma glutamate (in micromoles per liter (µmol/L)) to explore potential neurobiological correlates of treatment. Blood collected at baseline and follow-up.
Measured: Baseline and Week 1 (Day 7)
Beck Depression Inventory-II (BDI-II) total score
Self-reported symptoms of depression will be assessed using the 21-item Beck Depression Inventory-II, which provides a standardized index of depressive severity.
Each corresponding to a symptom of depression, rated on a scale from 0 to 3 based on intensity. The total score ranges from 0 to 63, with higher scores indicating more severe depressive symptoms. Score interpretation is as follows: 0-13 = minimal depression, 14-19 = mild depression, 20-28 = moderate depression, and 29-63 = severe depression.
Measured: Baseline (Day -1), Day 2, Day 7, and Day 84
State-Trait Anxiety Inventory (STAI) - State and Trait scores
Anxiety symptoms will be measured using the STAI, which provides separate scores for State Anxiety (how participants feel in the moment) and Trait Anxiety (how they generally feel).
The STAI consists of 40 items - 20 assessing state anxiety and 20 assessing trait anxiety - each rated on a 4-point Likert scale. Scores for each subscale range from 20 to 80, with higher scores indicating greater levels of anxiety. Generally, a score of 20-37 suggests low anxiety, 38-44 moderate anxiety, and 45-80 high anxiety.
Measured: Baseline (Day -1), Day 2, Day 7, and Day 84
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jul 2025
- Study start11 Dec 2025
- Primary completionNov 2026 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy VolunteersStudies of the same condition, open and under way.
- More trials run by Hadassah Medical OrganizationThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Model description
- The study will include 2 cohorts: First cohort of 5 participants will be recruited and administered a single dose of 15 mg of Psilocybin and 5 gr of D-Serine. Safety data will be collected, and an interim safety report will be submitted to the Ethics Committee (EC). Following administration to the initial cohort, safety and tolerability will be evaluated, and if no significant concerns are identified, the second cohort will be enrolled to receive a higher dose in order to determine the optimal dosage The second cohort of 5 participants will receive an increased one time dose of 25 mg of Psilocybin and 7 gr of D-Serine to determine the effective dose. The following visits will be conducted for both cohorts: Screening, Preparation, Administration (Day 1), and follow-up visits on Day 2, Day 7, Day 28, and Day 84.
- Masking
- None (open label)
- Enrolment
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hadassah Medical Organization
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07079930
- Sponsor's protocol ID
- Ps-PD-24-01-HMO-CTIL
- Status last verified
- Jul 2025
- First submitted
- 15 Jul 2025
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Safety and Psychological Effects of Psilocybin and D-Serine Formulation in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT07079930
- Acronym / sponsor ID
- Ps-PD-24-01-HMO-CTIL
- Conditions
- Healthy Volunteers
- Keywords
- psilocybin D-Serine healthy volunteers
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Hadassah Medical OrganizationUniversity, hospital or other
- Study start
- 11 Dec 2025 (actual)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Feb 2027 (estimated)
- First posted
- 23 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this open-label, dose-escalation, prospective study is to evaluate the safety and psychological effects of a Psilocybin and D-Serine formulation in healthy volunteers.
The main objectives are:
- To assess the psychological and physiological effects of psilocybin administered with D-Serine in healthy adults.
- To determine whether D-Serine modulates or attenuates the psychedelic effects of psilocybin.
- To evaluate the safety and tolerability of psilocybin and D-Serine co-administration.
Study population includes: 10 healthy male or female volunteers aged 25-60 years with no history of psychiatric or major medical disorders and no current evidence of such disorders.
The study includes two cohorts. The first cohort of 5 participants will receive 15 mg of Psilocybin and 5 g of D-Serine. Safety data will be collected and submitted in an interim report to the Ethics Committee. If no safety concerns arise, the second cohort will receive an increased dose of 25 mg of Psilocybin and 7 g of D-Serine to help determine the optimal dose for a future Phase IIa clinical trial.
Detailed description
This is a first-in-human, Phase I, exploratory clinical trial designed to evaluate the safety, tolerability, and initial psychological and physiological responses to a single administration of psilocybin in combination with D-Serine in healthy adult volunteers. The rationale for this combination stems from preclinical evidence indicating that D-Serine, a naturally occurring co-agonist at the NMDA receptor, may attenuate the acute psychedelic effects of psilocybin while preserving its neuroplastic and therapeutic properties.
Preclinical studies demonstrated that D-Serine reduced the psilocybin-induced head-twitch response (HTR) in rodent models and enhanced the expression of synaptic plasticity markers (e.g., GAP43, PSD95, SV2A, synaptophysin) across multiple brain regions, with effects sustained up to 12 days post-treatment. These findings suggest that the combination may improve the safety and tolerability of psilocybin, particularly for populations sensitive to its psychoactive effects.
The trial will consist of four sequential components:
Screening Phase - to assess eligibility.
Preparation Phase - to establish therapeutic rapport and baseline assessments.
Administration Phase - involving a single oral administration of the investigational combination (psilocybin + D-Serine).
Follow-up Phase - including in-person follow-up visits on Day 2, Day 7, Day 28, and Day 84 post-treatment to monitor safety outcomes, subjective responses, and potential delayed effects.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- The study will include 2 cohorts: First cohort of 5 participants will be recruited and administered a single dose of 15 mg of Psilocybin and 5 gr of D-Serine. Safety data will be collected, and an interim safety report will be submitted to the Ethics Committee (EC). Following administration to the initial cohort, safety and tolerability will be evaluated, and if no significant concerns are identified, the second cohort will be enrolled to receive a higher dose in order to determine the optimal dosage The second cohort of 5 participants will receive an increased one time dose of 25 mg of Psilocybin and 7 gr of D-Serine to determine the effective dose. The following visits will be conducted for both cohorts: Screening, Preparation, Administration (Day 1), and follow-up visits on Day 2, Day 7, Day 28, and Day 84.
| Arm | Type | Receives |
|---|---|---|
| 15 mg of Psilocybin and 5 gr of D-Serine | Experimental | Drug: Psilocybin and D-Serine, Diagnostic Test: Physical Examination, Diagnostic Test: Vital signs, Diagnostic Test: ECG test, Diagnostic Test: Comprehensive Blood Panel, Diagnostic Test: Complete Blood Count, Diagnostic Test: Urinalysis, Diagnostic Test: Urine Toxicology Screen, Diagnostic Test: A pregnancy Urine test, Diagnostic Test: Electroencephalogram, Diagnostic Test: Plasma Amino Acid Levels, Diagnostic Test: Plasma Inflammation Markers, Diagnostic Test: Plasma Brain-Derived Neurotrophic Facto, Other: Mini International Neuropsychiatric Interview, Other: Family Psychiatric History Assessment, Other: Beck Depression Inventory, Other: State-Trait Anxiety Inventory, Behavioral: Profile of Mood States, Behavioral: Subjective Units of Distress Scale, Other: Five-Dimensional Altered States of Consciousness questionnaire, Behavioral: IntegrationThe investigational drug, 15 mg of Psilocybin and 5 g of D-Serine, will be administered as a single oral dose in solution form. |
| 25 mg of Psilocybin and 7 gr of D-Serine | Experimental | Drug: Psilocybin and D-Serine, Diagnostic Test: Physical Examination, Diagnostic Test: Vital signs, Diagnostic Test: ECG test, Diagnostic Test: Comprehensive Blood Panel, Diagnostic Test: Complete Blood Count, Diagnostic Test: Urinalysis, Diagnostic Test: Urine Toxicology Screen, Diagnostic Test: A pregnancy Urine test, Diagnostic Test: Electroencephalogram, Diagnostic Test: Plasma Amino Acid Levels, Diagnostic Test: Plasma Inflammation Markers, Diagnostic Test: Plasma Brain-Derived Neurotrophic Facto, Other: Mini International Neuropsychiatric Interview, Other: Family Psychiatric History Assessment, Other: Beck Depression Inventory, Other: State-Trait Anxiety Inventory, Behavioral: Profile of Mood States, Behavioral: Subjective Units of Distress Scale, Other: Five-Dimensional Altered States of Consciousness questionnaire, Behavioral: IntegrationThe investigational drug, 25 mg of Psilocybin and 7 g of D-Serine, will be administered as a single oral dose in solution form. |
Who may qualify
- Ages
- 25 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Aged 25-60 years, male or female.
- Medically healthy, as confirmed by a comprehensive clinical assessment.
- Written informed consent provided.
Key exclusion criteria (7 listed)
- History of any Axis 1 psychiatric disorder requiring pharmacotherapy such as schizophrenia, schizoaffective disorder, any other psychotic disorder, bipolar disorder, as well as non-psychotic disorders such as generalized anxiety disorder, major depressive disorder, obsessive-compulsive disorder, posttraumatic stress disorder.
- Family history (among first-degree relatives) of schizophrenia, bipolar disorder, or other psychotic disorder
- History of cardiovascular disorders.
- Pregnant or breastfeeding women or women of childbearing age not using effective contraception.
- Use of psilocybin or other psychedelic compound in the 12 months preceding the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Psilocybin and D-SerineA single administration of the drug, with dosage divided as follows: Cohort 1: 15 mg of Psilocybin and 5 gr of D-Serine Cohort 2: 25 mg of Psilocybin and 7 gr of D-Serine | Drug | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Physical ExaminationThe physical examination will include diagnosis and documentation of any significant clinical abnormalities or diseases. It will be performed during the baseline rating visit (preparation phase). | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Vital signsVital sign measurements (blood pressure, pulse, and oxygen saturation) will be taken at screening, preparation, baseline rating, administration day, day 2, day 28, and day 84. Vital signs will be assessed at the following time points on the administration day and on day 2: pre-administration, and at 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, and 24 hours post-administration. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| ECG testA 12-lead ECG will be performed to rule out underlying cardiac abnormalities. An ECG will be conducted for each patient during the screening and Day 2 visits. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Comprehensive Blood PanelAlso: SMAC-20A comprehensive blood panel will be performed to assess kidney and liver function, electrolyte balance, and glucose levels. It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Complete Blood CountAlso: CBCComplete Blood Count will be performed to check for hematological abnormalities. It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| UrinalysisUrinalysis will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Urine Toxicology ScreenUrine Toxicology Screen will be performed to rule out illicit drug use. It will be conducted during the Screening visit, and on Day 2, Day 28, and Day 84. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| A pregnancy Urine testA urine pregnancy test will be performed for women of childbearing potential only. It will be conducted during the screening and baseline rating visits. If the urine test is positive, a serum β-hCG test will be performed for confirmation. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| ElectroencephalogramAlso: EEGEEG will be performed during the baseline rating scale and Day 7 visits to evaluate brain activity | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Plasma Amino Acid LevelsThe following blood test parameters - D-Serine, L-Serine, and Glycine - will be assessed during the Screening and Day 28 visits. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Plasma Inflammation MarkersThe following blood test parameters - Tumor Necrosis Factor Alpha (TNF-α), Interleukin-6 (IL-6), and C-Reactive Protein (CRP) - will be assessed during the Screening and Day 28 visits. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Plasma Brain-Derived Neurotrophic FactoAlso: Plasma BDNFPlasma BDNF (Brain-Derived Neurotrophic Factor) levels will be measured during the screening and Day 28 visits. | Diagnostic test | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Mini International Neuropsychiatric InterviewAlso: MINIThe Mini International Neuropsychiatric Interview (MINI) will be administered during the screening visit to rule out any current or past major psychiatric disorders. | Other | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Family Psychiatric History AssessmentAlso: FPHAThe Family Psychiatric History Assessment (FPHA) will be administered during the screening visit to help rule out any current or past major psychiatric disorders. | Other | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Beck Depression InventoryAlso: BDIThe Beck Depression Inventory (BDI) will be administered at the following visits: screening, baseline, day 7, day 28, and day 84. It will be used to assess baseline mood and to rule out depressive symptoms. | Other | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| State-Trait Anxiety InventoryAlso: STAIState-Trait Anxiety Inventory (STAI) will be administered at the following visits: screening, baseline, day 7, day 28, and day 84. It will be used to screen for anxiety disorders. | Other | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Profile of Mood StatesAlso: POMSThe Profile of Mood States (POMS) will be administered to assess baseline mood and emotional state. It will be administered at the following visits: screening, baseline, administration day, day 2, day 7, day 28, and day 84. On the administration day and on day 2, it will be administered at the following time points: pre-administration, and 8 and 20 hours post-administration. | Behavioural | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Subjective Units of Distress ScaleAlso: SUDSSubjective Units of Distress Scale (SUDS) will be administered to assess anxiety and stress levels. It will be administered at the following visits: screening, baseline, administration day, day 2, day 7, day 28, and day 84. On the administration day and on day 2, it will be administered at the following time points: pre-administration, and 8 and 20 hours post-administration. | Behavioural | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| Five-Dimensional Altered States of Consciousness questionnaireAlso: 5D-ASCThe Five-Dimensional Altered States of Consciousness questionnaire (5D-ASC) will be used to assess the acute subjective psychedelic experience. It will be administered after the acute effects have subsided - at 6.0 hours post-administration on the administration day, and again on day 2 - to evaluate five key experiential dimensions: visual restructuralization, oceanic boundlessness, reduction of vigilance, anxious ego dissolution, and auditory alterations. Each item will be rated using a Visual Analogue Scale (VAS) ranging from "NO, not more than usually" (0 mm) to "YES, much more than usually" (100 mm). | Other | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
| IntegrationThe integration process is conducted to support participants in processing and incorporating their therapeutic experience into daily life, with the aim of enhancing emotional insight and psychological well-being. Integration will take place at the following visits: 8.0 hours post-treatment on the administration day, day 2, day 7, day 28, and day 84. | Behavioural | 15 mg of Psilocybin and 5 gr of D-Serine, 25 mg of Psilocybin and 7 gr of D-Serine |
Primary outcome
Incidence and severity of treatment-emergent adverse events (TEAEs) following administration of psilocybin and D-serine
Time frame: From time of dosing (Day 1) through Day 84 (final follow-up visit)
The number, type, severity, timing, and relatedness of treatment-emergent adverse events following administration of psilocybin and D-serine. Adverse events will be assessed through continuous clinical monitoring, spontaneous reports, and structured instruments including the UKU Side Effect Rating Scale. Safety will also be evaluated via changes in vital signs, ECG, and laboratory tests (SMAC-20, CBC, urinalysis). Events will be classified using standard regulatory definitions and graded for severity and relatedness to study treatment.
9 secondary outcomes
Change in subjective psychedelic experience measured by the 5D-ASC scale
Time frame: 6 hours post-dosing and Day 2 follow-up
Change in mood states assessed by the Profile of Mood States (POMS)
Time frame: Baseline, 8 and 20 hours post-dosing, Day 2, Week 1, and Day 84
Change in anxiety and stress measured by the Subjective Units of Distress Scale (SUDS)
Time frame: Baseline, 8 and 20 hours post-dosing, Day 2
Change in plasma D-serine concentration
Time frame: Baseline and Week 1 (Day 7)
Change in plasma inflammatory markers concentration.
Time frame: Baseline and Week 1 (Day 7)
Change in plasma BDNF concentration
Time frame: Baseline and Week 1 (Day 7)
Change in plasma glutamate concentration
Time frame: Baseline and Week 1 (Day 7)
Beck Depression Inventory-II (BDI-II) total score
Time frame: Baseline (Day -1), Day 2, Day 7, and Day 84
State-Trait Anxiety Inventory (STAI) - State and Trait scores
Time frame: Baseline (Day -1), Day 2, Day 7, and Day 84
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2026.
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Screening Protocol
Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Psilocybin and D-Serine, Physical Examination and Vital signs in people with Healthy Volunteers, run by Hadassah Medical Organization at 1 site in Israel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Israel. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Bernard Lerer, MD (+972-50-7874575, lerer@mail.huji.ac.il), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence and severity of treatment-emergent adverse events (TEAEs) following administration of psilocybin and D-serine (time frame: From time of dosing (Day 1) through Day 84 (final follow-up visit)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Feb 2026.