Inclusion Criteria:
* Patient must have ≥ 3 clinically atypical nevi, assessed within 30 days prior to randomization, that are consistent with the International Agency for Research on Cancer (IARC) definition as follows.
* Must have a diameter of ≥ 5mm in one dimension
* Must include a macular component in at least one area
* Must have at least two of the following features: ill-defined borders, color variegation, uneven contour, and erythema NOTE: Lesions suspicious for incipient melanoma will be removed and are not intended for the study
* Patient must have a prior diagnosis of early-stage melanoma, defined as either melanoma in situ, localized resected stage I-II node negative melanoma, or resected node negative stage III melanoma who in the assessment of their physician have a low risk of relapse of their prior melanoma within one year of randomization
* Patient must not be currently on targeted or checkpoint immunotherapy or treated within 365 days prior to randomization
* Patient must be ≥ 18 years of age
* Patient must not be pregnant. All patients of childbearing potential must have a blood test or urine study within 14 days prior to randomization to rule out pregnancy. A patient of childbearing potential is defined as anyone, regardless of sexual orientation or whether they have undergone tubal ligation, who meets the following criteria: 1) has achieved menarche at some point, 2) has not undergone a hysterectomy or bilateral oophorectomy; or 3) has not been naturally postmenopausal (amenorrhea following cancer therapy does not rule out childbearing potential) for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months)
* Patient must not expect to conceive or father children by using accepted and effective method(s) of contraception or by abstaining from sexual intercourse for the duration of their participation in the study and for at least 30 days after the last dose of protocol treatment
* Patient must have the ability to understand and the willingness to sign a written informed consent document. Patients with impaired decision-making capacity (IDMC) who have a legally authorized representative (LAR) or caregiver and/or family member available will also be considered eligible
* Human immunodeficiency virus (HIV)-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months of randomization are eligible for this trial
* For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated
* Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load
* Patients with a prior or concurrent malignancy (other than the melanoma for which they are on this study), whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen, are eligible for this trial
* Patient must not have a known allergy to cruciferous vegetables
* Patients must not use any other sulforaphane-containing dietary supplement during the study period
* Patient must not be on any current systemic treatment for melanoma
