Investigating the effects of THC and d-limonene in healthy adults

Behavioral Pharmacology of Orally Administered THC and D-limonene

Phase 1 Interventional Johns Hopkins University · NCT06378957

This study is testing if a compound called d-limonene can change how THC affects healthy adults when both are taken together in a pill form.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment65 (estimated)
Ages21 Years to 55 Years
SexAll
SponsorJohns Hopkins University Academic / other
Locations1 site (Baltimore, Maryland)
Trial IDNCT06378957 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to explore how orally administered d-limonene interacts with delta-9-tetrahydrocannabinol (THC) in healthy adult volunteers. The study will assess whether d-limonene can modulate the effects of THC when both substances are taken orally, similar to previous findings with inhalation. Participants will undergo six outpatient drug administration sessions, receiving either placebo, THC alone, or varying doses of d-limonene combined with THC. The trial will recruit up to 20 participants who have prior experience with cannabis.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 21 to 55 with prior experience using high THC cannabis products.

Not a fit: Patients who are pregnant, nursing, or have significant health issues or allergies to the study substances may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of how d-limonene affects THC's effects, potentially leading to improved therapeutic applications of cannabis.

How similar studies have performed: Previous studies have shown that inhaled limonene can influence THC effects, suggesting potential for success in this oral administration approach.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Baltimore, Maryland

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Subjective Drug EffectsTHCD-limonene
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.