A double blind Randomized Controlled Trial with two arms will be used. Subjects with Alcohol use disorder and sleep problems will be recruited and assigned randomly to the active treatment Melatonin or Placebo arms. All subjects will be assessed at baseline for demographics. Sleeping problems will be the primary outcome of the study, and it will be measured by the Pittsburgh sleep quality index (PSQI) scale.

A double blind Randomized Controlled Trial with two arms will be used. Subjects with Alcohol use disorder and sleep problems will be recruited and assigned randomly to either Melatonin or Placebo arms. All subjects will complete some forms on the REDCap system such as contact information list, concomitant medication, Time Line Follow Back (TLFB), Fagerstrom test for nicotine dependence (FTND), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), AUD criteria, and Alcohol use disorder identification test (AUDIT). Sleeping problems will be the primary outcome of the study, and it will be measured by the Pittsburgh sleep quality index (PSQI) scale where score 5 or more indicated a sleeping problem. Women in child-bearing period will be asked to do a urine pregnancy test to exclude pregnancy. After verifying eligibility, the participants will come to pick up the medication (Melatonin or placebo) blister together with a sleep hygiene document and will start taking the medication for 4 weeks. All subjects will then be followed-up at the end of 1 month of treatment and PSQI score will be measured. This step will be completed either online by sending an email link through or the participants can come to a personal visit to complete the second PSQI form. Also, this last visit/email will contain side effects questionnaire, TLFB, BDI, BAI. All the participants will be required to bring/send back the medication blister pack to do a pill count and check all the missing pills.

Inclusion Criteria:

• Age: 19 or older
• AUD in any stage
• Sleep problems in the past month
• PSQI score > 5 at baseline
• Participants must agree not to use other sleep aid during the study
• Women capable of becoming pregnant must agree to use contraceptives during study

Exclusion Criteria:

• Pregnancy, lactation or plans to become pregnant during the study timeline.
• Use of other sleep aid in the past month (either prescribed or over the counter remedies)
• Use of benzodiazepines and/or Z- drugs: (zaleplon, zolpidem and zopiclone) in the past month
• Known allergy to melatonin
• Participants taking immunosuppressive drugs.