Cinnamon for Drug-Food Interaction

Overseen By Deena L Hadi, BS

Age: 18 - 65

Sex: Any

Trial Phase: Phase < 1

Sponsor: Washington State University

Must not be taking: Prescription drugs, Herbal supplements

Disqualifiers: Chronic illness, Psychiatric illness, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine how cinnamon, a common spice, might affect the way certain drugs work in healthy individuals. Researchers seek to understand whether cinnamon alters the body's processing of letrozole, a cancer medication, and nicotine gum, used to aid smoking cessation. The goal is to explore cinnamon's potential as a smoking cessation aid and its impact on letrozole treatment. Healthy individuals not taking any medications or supplements and who can avoid certain foods and drinks for a period are ideal candidates for this study. As an Early Phase 1 trial, this research focuses on how cinnamon interacts with these drugs, offering participants a chance to contribute to groundbreaking research.

Will I have to stop taking my current medications?

Yes, you will need to stop taking any medications or supplements that could affect the study drugs or cinnamon. The trial requires participants to not take any such medications or supplements.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that cinnamon might affect how the body processes certain medications. One study found that compounds in cinnamon, such as cinnamaldehyde, could slow the breakdown of drugs in the body. This might alter the effectiveness of these drugs or extend their presence in the system.

Nicotine gum is generally safe when used properly. However, combining it with other substances, like cinnamon, might cause side effects such as an increased heart rate.

Letrozole, a medication commonly used to treat breast cancer, has received FDA approval, indicating it has undergone safety testing in humans.

This trial is in its early phase, meaning researchers are still gathering initial safety information. This phase typically involves a small group of participants to learn more about side effects and how the body processes the treatment. So far, no major safety issues have been reported, but further studies are needed to confirm this. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about this trial because it explores how cinnamon might affect drug-food interactions, specifically with letrozole and nicotine gum. Unlike standard treatments, which typically focus on the drug alone, this study investigates whether cinnamon can influence how the body processes these compounds. Cinnamon is a natural product that might alter drug absorption or metabolism, potentially leading to new ways to enhance drug effectiveness or reduce side effects. By examining these interactions, scientists hope to uncover novel insights that could optimize how medications are used in combination with certain foods or supplements.

What evidence suggests that this trial's treatments could be effective?

Research has shown that cinnamon can affect how the body processes certain drugs. This trial involves participants in different arms to study these effects. One arm investigates how cinnamon, when combined with letrozole, might alter the breakdown of letrozole in the body. Another arm explores the interaction between cinnamon and nicotine gum, examining how cinnamon might influence nicotine metabolism. These findings suggest that cinnamon could help people stop smoking and might affect how some drugs function in the body. ^{1 2 4 6 7}

Are You a Good Fit for This Trial?

Healthy adults aged 18-64 who don't take medications or supplements that affect the study drugs, can avoid caffeine, alcohol, and certain contraceptives before and during the trial. They must not be pregnant or nursing and willing to use non-hormonal contraception.

Inclusion Criteria

I have the time to commit to this clinical trial.

Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for the subject to comply with the requirements of the study

Willing to abstain from consuming caffeinated beverages or other caffeine-containing products the evening before and morning of the first day of a study arm

Exclusion Criteria

I have a major or chronic illness like kidney disease, heart issues, or diabetes.

I am allergic to cinnamon, letrozole, or nicotine.

I am not on medications that affect how study drugs or cinnamon work in my body.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Cinnamon Administration

Participants receive a single dose of cinnamon (2 g) with water by mouth

0-48 hours

1 visit (in-person)

Nicotine Administration

Participants receive a single dose of nicotine gum (2 mg)

0-12 hours

1 visit (in-person)

Cinnamon + Letrozole Administration

Participants self-administer cinnamon (2 g) three times daily for five days, followed by cinnamon and letrozole (2.5 mg) on the sixth day

6 days

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Cinnamon
• Letrozole
• Nicotine gum

Trial Overview The study tests how a cinnamon supplement affects the body's handling of nicotine gum and letrozole, which are used as test drugs to understand cinnamon's potential impact on drug metabolism in healthy volunteers.

How Is the Trial Designed?

Group I: Nicotine Experimental Treatment 1 Intervention

Arm 2 will consist of administration of a single dose of nicotine gum (2 mg) to 16 subjects (8 biological men, 8 biological women). If these subjects participated in Arm 1, they will have completed a washout of 7 days since administration of cinnamon before starting Arm 2. Blood and urine will be collected from 0-12 hours relative to nicotine administration. Participants will undergo a washout of at least 4 days before beginning Arm 3.

Group II: Letrozole Experimental Treatment 1 Intervention

Arm 3 will consist of administration of a single oral dose of letrozole (2.5 mg) to the same 16 subjects who participate in Arm 2. Blood and urine will be collected from 0-240 hours and 0-24 hours, respectively, relative to letrozole administration. Participants will undergo a washout of at least 14 days before beginning Arm 4.

Group III: Cinnamon + Nicotine Experimental Treatment 2 Interventions

The same 16 subjects will self-administer the cinnamon product (2 g) three times daily for five consecutive days. On the sixth day, subjects will be administered cinnamon (2 g) and nicotine gum (2 mg). Cinnamon will be administered two additional times. Blood and urine will be collected from 0-12 hours relative to nicotine administration. Participants will undergo a washout of at least 4 days before beginning Arm 5.

Group IV: Cinnamon + Letrozole Experimental Treatment 2 Interventions

The same 16 subjects will self-administer the cinnamon product (2 g) three times daily for five consecutive days. On the sixth day, subjects will be administered cinnamon (2 g) and letrozole (2.5 mg). Cinnamon will be administered two additional times. Blood and urine will be collected from 0-240 hours and 0-24 hours, respectively, relative to letrozole administration.

Group V: Cinnamon Experimental Treatment 1 Intervention

Arm 1 will consist of administration of a single dose of cinnamon (2 g) with water by mouth to 6 subjects (3 biological men, 3 biological women). Blood will be drawn from 0-48 hours. Urine will be collected from 0-24 hours. The subjects may or may not elect to participate in Arms 2-5. If they do, a washout of at least 7 days will occur between Arm 1 administration of cinnamon and the Arm 2 administration of nicotine.

Letrozole is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Femara for:

• Breast cancer in postmenopausal women
• Increasing the chance of ovulation in women with polycystic ovary syndrome

Approved in European Union as Letrozole for:

• Early breast cancer in postmenopausal women
• Advanced breast cancer in postmenopausal women

Approved in Canada as Letrozole for:

• Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer
• First-line treatment of postmenopausal women with hormone receptor-positive advanced breast cancer

Who Is Running the Clinical Trial?

Washington State University

Lead Sponsor

Trials

114

Recruited

58,800+

National Center for Complementary and Integrative Health (NCCIH)

Collaborator

Trials

886

Recruited

677,000+

Office of Dietary Supplements (ODS)

Collaborator

Trials

55

Recruited

54,500+

Published Research Related to This Trial

In a study of 158 smokers, transdermal nicotine patches significantly improved smoking cessation rates, with 39% of participants using 24-hour patches and 35% using patches during wakeful hours achieving abstinence, compared to only 13.5% in the placebo group.

The nicotine patches also effectively reduced tobacco withdrawal symptoms during the initial weeks of quitting, demonstrating their safety and efficacy as an adjunct to low-intervention therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Effects of transdermal nicotine as an adjunct in smoking cessation therapy. A double-blind randomized study controlled with placebo]. Daughton, DM., Heatley, SA., Prendergast, JJ., et al.[2015]

Nicotine gum, which binds nicotine to a polacrilex, is an effective method for treating tobacco dependence by transferring nicotine dependence from cigarettes to a safer form, reducing the risk of relapse.

The effectiveness of nicotine gum can be influenced by factors such as the dose, dosing schedule, and how vigorously it is chewed, highlighting the importance of proper administration for optimal results.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Physiologic effects of nicotine polacrilex. Nemeth-Coslett, R.[2019]

In a study of 158 smokers, transdermal nicotine patches significantly improved smoking cessation rates, with 39% of participants using 24-hour patches and 35% using patches during wakeful hours achieving abstinence, compared to only 13.5% in the placebo group.

The nicotine patches also effectively reduced tobacco withdrawal symptoms during the initial weeks of quitting, demonstrating their safety and efficacy as an adjunct to low-intervention therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of transdermal nicotine delivery as an adjunct to low-intervention smoking cessation therapy. A randomized, placebo-controlled, double-blind study. Daughton, DM., Heatley, SA., Prendergast, JJ., et al.[2017]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7543486/

Mechanisms of Herb-Drug Interactions Involving Cinnamon ... Mechanisms of herb-drug interactions involving cinnamon and CYP2A6: focus on time-dependent inhibition by Cinnamaldehyde and 2-Methoxycinnamaldehyde.

2. withpower.com withpower.com/trial/early-phase-1-10-2021-29ea8

Cinnamon for Drug-Food Interaction · Info for Participants Studies show it can effectively help reduce smoking with minimal discomfort or risk of relapse, and it avoids harmful substances found in cigarette smoke like ...

3. olemiss.edu olemiss.edu/news/2025/04/cinnamon-drug-interactions/index.html

Cinnamon Could Affect Drug Metabolism in the Body A new study from the National Center for Natural Products Research indicates a compound in it could interfere with some prescription medications.

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0090955624079248

Natural Products: Experimental Approaches to Elucidate ... This special issue contains a collection of articles highlighting the challenges faced by researchers in the field and the use of various experimental systems ...

5. researchgate.net researchgate.net/publication/343622776_Mechanisms_of_Herb-Drug_Interactions_Involving_Cinnamon_and_Cytochrome_P450_2A6_Focus_on_Time-dependent_Inhibition_by_Cinnamaldehyde_and_2-Methoxycinnamaldehyde

Mechanisms of Herb-Drug Interactions Involving Cinnamon ... Predictions regarding herb-drug interactions suggest that prolonged exposure to cinnamon may result in significant interactions, particularly with nicotine [ ...

6. drugs.com drugs.com/drug-interactions/cinnamon.html

Cinnamon Interactions Checker Does cinnamon interact with my other drugs? Enter medications to view a detailed interaction report using our Drug Interaction Checker.

7. cnn.com cnn.com/2025/05/08/health/cinnamon-interactions-medications-wellness

Cinnamon could interact with some prescription ... People should be cautious because cinnamon could affect the metabolism of prescription drugs, according to a study published in the journal Food Chemistry: ...