Recruiting
Phase 1

Limonene & THC

Sponsor:

Johns Hopkins University

Code:

NCT06378957

Conditions

Subjective Drug Effects

THC

D-limonene

Eligibility Criteria

Sex: All

Age: 21 - 55

Healthy Volunteers: Accepted

Interventions

D-Limonene

Delta-9-THC

Placebo

Study Details

Brief summary:

The current clinical trial will investigate the effects of orally administered d-limonene (limonene), delta-9-tetrahydrocannabinol (THC) and the combination in healthy adult volunteers.

Conditions

Subjective Drug Effects

THC

D-limonene

Study ID

NCT06378957

Start date

Feb 14, 2025

Status verified date

May, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Jul 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 21 - 55

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Have provided written informed consent
  • Be between the ages of 21 and 55
  • Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
  • Test negative for drugs of abuse other than cannabis, including breath alcohol at the screening visit and at clinic admission
  • Not be pregnant or nursing (if female). All females must have a negative serum pregnancy test at the screening visit and a negative urine pregnancy test at clinic admission.
  • Have a body mass index (BMI) in the range of 18 to 36 kg/m2
  • Blood pressure at Screening Visit does not exceed a systolic blood pressure (SBP) of 150 mmHg or a diastolic blood pressure (DBP) of 90 mmHg
  • Have no allergies to any of the ingredients used to prepare (cellulose, THC, d-limonene).
  • Report having used a high THC cannabis product in the past 3 years and having experienced anxiety after consuming cannabis at least once in lifetime.

Exclusion Criteria:

  • Non-medical use of psychoactive drugs other than, nicotine, alcohol, or caffeine 3 month prior to the Screening Visit;
  • History of or current evidence of significant medical (e.g. seizure disorder) or psychiatric illness (e.g. psychosis) judged by the investigator to put the participant at greater risk of experiencing an adverse event due to exposure or completion of other study procedures.
  • Use of an over the counter (OTC), systemic or topical drug(s), herbal supplement(s), or vitamin(s) within 14 days of experimental sessions; which, in the opinion of the investigator or sponsor, will interfere with the study result or the safety of the subject.
  • Use of a prescription medication (with the exception of birth control prescriptions) within 14 days of experimental sessions; which, in the opinion of the investigator or sponsor, will interfere with the study result or the safety of the subject.
  • Average use of cannabis more than 2 times per week in the prior 3 months.
  • History of clinically significant cardiac arrhythmias or vasospastic disease (e.g., Prinzmetal's angina).
  • Enrolled in another clinical trial or have received any drug as part of a research study within 30 days prior to dosing.
  • Individuals with anemia or who have donated blood in the prior 30 days

Study Design

Enrollment

65 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

placebo comparator: Oral Placebo

Placebo (cellulose), via capsule

experimental: Oral THC 30mg

30mg pure THC in ethanol vehicle, via capsule

experimental: Oral THC 30mg + D-Limonene 25mg

30mg pure THC in ethanol vehicle, via capsule 25mg pure D-Limonene, via capsule

experimental: Oral THC 30mg + D-Limonene 50mg

30mg pure THC in ethanol vehicle, via capsule 50mg pure D-Limonene, via capsule

experimental: Oral THC 30mg + D-Limonene 100mg

30mg pure THC in ethanol vehicle, via capsule 100mg pure D-Limonene, via capsule

experimental: Oral THC 30mg + D-Limonene 200mg

30mg pure THC in ethanol vehicle, via capsule 200mg pure D-Limonene, via capsule

Interventions

D-Limonene

Oral Limonene administered via capsule

Delta-9-THC

Oral delta-9-THC in ethanol vehicle administered via capsule

Placebo

Placebo (cellulose) administered via capsule

Primary outcome measure

  • Subjective Drug Effect as assessed by Visual Analog Scale [ Time Frame: 8 hours after dosing ]

Central Contacts and Locations

Central contacts

Austin Zamarripa, PhD

410-550-6969czamarr2@jhmi.edu

Lauren S Pollak, MSc

410-550-0586lschoen7@jhmi.edu

Locations

Johns Hopkins Behavioral Pharmacology Research Unit

Recruiting

Baltimore, Maryland, United States, 21224

Principal Investigator:

Austin Zamarripa, PhD

More Information

Sponsor

Johns Hopkins University

Last update posted

May 28, 2026

Last verified

May, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Johns Hopkins University on 2026-05-28.