Vivitrol, a drug meant to help ex-opioid users stay clean, has finally been shown to be able to control cravings just as much as its competition, according to a new study sponsored by the National Institute on Drug Abuse.

This study is the largest head-to-head study to date between two leading drugs – a monthly shot of naltrexone (sold as Vivitrol) and its main competitor, the daily pill of buprenorphine and naloxone (sold as Suboxone). Both drugs are used in drug treatment centers and even correctional facilities to help people with substance abuse disorders fight cravings and ultimately achieve long periods of sobriety. The study found that about half of people with opioid addiction who took either drug remained clean from opioids six months after starting the drug therapy. Before this study, doctors believed that patients don’t do as well on the Vivitrol. Dr. Nora Volkow, director of NIDA, told reporters that “We’re hopeful this changes the prejudice.”

A monthly drug may be helpful to those with a substance abuse disorder who are forgetful or unable to tolerate pills, or somebody who lives too far from a clinic to get Suboxone. Vivitrol was first approved by the FDA as an opioid treatment. It’s a preferred method for some people because patients only have to take it once a month, and it doesn’t contain opioids. Correctional facilities have found it to be an easy way to help their inmates attending treatment and 12 step meetings to stay clean. However, the drug simply isn’t for everyone. Suboxone may be a better option for pain patients because it blocks pain receptors or for those who are in danger of relapse directly after detox.

Many study participants couldn’t even start the study due to the requirements for taking the drug; to use Vivitrol, users must have thoroughly weaned themselves off opioids for a period of three days. Because of this difficulty, many patients failed to even start on Vivitrol. However, patients that have gone through supervised detox may find this drug to be more helpful once they have gotten clean and still have long-term cravings.

Suboxone had 4 times as many people who qualified for treatment in the study. However, many treatment facilities and correctional facilities dislike it, saying it is simply substituting one opioid for another. Vivitrol doesn’t cause this concern.

Previously, there were few studies showing Vivitrol’s effectiveness. Now, it seems, this study has paved the way for more widespread use.