A study of over 300 patients receiving naltrexone found that it was equally effective for patients with a wide range of demographic, addiction, mental health, legal, employment, family, and social issues. One notable exception was that naltrexone did not work as well for patients with a recent history of drinking alcohol to the point of intoxication.

Because naltrexone injections must be administered by trained healthcare professionals, individuals who want to receive naltrexone must have access to clinics offering this medication and have transportation and scheduling flexibility to make an appointment. Similar flexibility in life responsibilities and work, and access to transportation, is also needed to successfully undergo the medically supervised withdrawal or period of opioid abstinence required to start naltrexone for the first time. Studies have also found evidence suggesting that people with opioid use disorder are more likely to learn about methadone and buprenorphine from peers and more likely to learn about naltrexone from healthcare professionals, suggesting that naltrexone may be less likely to reach individuals outside of the healthcare system. Studies outside the United States have suggested that patients who started using opioids at a younger age, those with lower socio-economic status, and those with comorbid mental health and substance use problems have the worst retention on naltrexone, suggesting that these individuals may require additional support.