Can broccoli extract help smokers' bodies remove tobacco toxins?

Plain-English translation of NCT05121051 on ClinicalTrials.gov ↗ · Source last updated July 2026 · Translation generated August 2026 · How we translate trials

Phase 2 — Testing in a bigger group (up to a few hundred people) to see if the treatment actually works and is still safe.

What is this trial?

This trial is testing whether Avmacol ES, a broccoli seed and sprout extract supplement, can help your body get rid of harmful cancer-causing chemicals from cigarette smoke. The supplement contains a compound called sulforaphane, which is naturally found in broccoli. Researchers want to know if taking this medication daily for 12 weeks will increase the amount of these toxins your body gets rid of through urine.

Heavy smokers are exposed to dangerous chemicals in tobacco that can cause cancer. This study exists to see if this medication could help your body's natural detoxification system work better, potentially lowering your cancer risk.

Do you qualify?

You likely qualify if…

you are a current smoker with at least 20 pack-years of smoking history (roughly 1+ pack per day for 20 years) and smoke at least 10 cigarettes per day
you are 18 years old or older
you have relatively healthy liver, kidney, and blood cell counts as measured by routine blood tests
you are not pregnant or nursing, and are willing to use birth control during the study if you could become pregnant
you can understand the study and are willing to sign a consent form

You likely don't qualify if…

you have had cancer in the past 2 years (except non-melanoma skin cancer or cervical cancer in situ)
you are currently taking any supplements or products containing sulforaphane or glucoraphanin (though you can join if you stop for 7 days before starting)
you have HIV, active hepatitis B, or untreated hepatitis C infection
you have severe heart, infection, or other serious medical conditions that are not well controlled
you are allergic to broccoli or related compounds

What participation looks like

You will visit the research clinic multiple times over 12 weeks. Half of participants will take the broccoli extract supplement by mouth once daily, and half will take a placebo (inactive pill), though neither you nor the researchers will know which you're receiving. Throughout the study, researchers will collect blood samples, cells from inside your nose, and cells from the inside of your cheek to measure whether the supplement is helping your body remove tobacco toxins. After the 12 weeks end, you'll have one final follow-up visit 2 to 4 weeks later.

AI-generated summary from trial data · Aug 22, 2026 · Not medical advice

Trial locations(3 sites)

United States

University of Arizona Cancer Center - Prevention Research Clinic, Tucson, Arizona

George Washington University Medical Center, Washington D.C., District of Columbia

Roswell Park Cancer Institute, Buffalo, New York