Sublocade, an injectable form of buprenorphine, could benefit many people with opioid use disorder, but few people are using it because regulatory challenges can make it difficult for doctors to administer the treatment, the Los Angeles Times reports.

Sublocade is administered once a month. In contrast, oral buprenorphine is taken daily. Providing a monthly treatment is especially beneficial for people without housing or who have other instabilities, according to Dr. Andrew Herring, who works in the addiction clinic at Highland Hospital in Oakland, California.

Herring said many of his patients who are prescribed oral buprenorphine fall out of treatment. It is much less expensive than Sublocade, however — less than $100 per month compared with almost $2,000 per month for the injectable version. While few patients pay the full price for Sublocade, some private insurance companies don’t cover it. There is no competing or generic version of the medication.

In order to prescribe Sublocade, providers must register with the Drug Enforcement Administration and obtain a waiver. Clinics also must complete a Food and Drug Administration (FDA) safety certification program. The medication must be ordered by a specialty pharmacy, which also must complete the FDA program.

In addition, some state Medicaid plans require prior authorization, which can lead to months-long waits for Sublocade.