A new study finds a long-acting medication and a short-term drug that must be taken daily are equally effective in treating opioid addiction.

Researchers at NYU Langone Health found extended-release naltrexone (Vivitrol) was as safe and effective as more commonly prescribed buprenorphine-naloxone (Suboxone) in curtailing opioid use, relapse, treatment drop-out, and overdose. The study, which was sponsored by the National Institute on Drug Abuse, was published in The Lancet.

The study is the first major head-to-head comparison of the treatments, according to The Washington Post. Researchers found each treatment had disadvantages. Short-acting medicines must be taken daily for years or even a lifetime. Naltrexone, which is given as a monthly injection, cannot be started until a person is fully detoxified from opioids—which more than 25 percent of the study subjects failed to do.

More than half of the study subjects relapsed at least once, regardless of which treatment they received.