Inadequate access to opioid addiction treatment programs has led to a thriving black market for Suboxone, the drug that helps patients overcome their addiction, experts tell The Wall Street Journal.

More than 36,000 doctors are certified in the United States to prescribe Suboxone and other buprenorphine-based medications. Until last year, those doctors were limited to prescribing the drugs to 100 patients each. Last year, the Obama Administration increased that number to 275, and began allowing physician assistants and nurse practitioners to prescribe the drugs.

So far only about 3,000 doctors have received approval to treat up to 275 patients, the article notes. “If the providers were geographically distributed appropriately and if they all worked at capacity, we would now have adequate capacity,” a federal spokesman told the newspaper. “But of course they are not, so there is unmet need.”