The Food and Drug Administration (FDA) posted an Adderall shortage this week, warning that manufacturers will not be able to meet the U.S. market demand at the current rate of production.

While several manufacturers are still producing and supplying Adderall, major pharmaceutical companies are currently dealing with issues affecting their production, said the FDA in its notice.

Adderall — or mixed amphetamine salts — is a popular drug commonly prescribed for ADHD and narcolepsy. The FDA said in its notice that “alternative therapies” for these conditions were available and advised that patients speak with a health care professional on what the best treatment plan would be.

Teva Pharmaceuticals, the largest U.S. supplier of Adderall, has been dealing with an ongoing supply disruptions since at least August. The FDA on Wednesday said the company was “experiencing ongoing intermittent manufacturing delays.”

Rhodes Pharmaceuticals, a subsidiary of Purdue Pharma, is experiencing a shortage of its 5 mg bottles of 100 tablets of Adderall. The reason for the lack of availability cited in the FDA’s post is “shortage of active ingredient.”

In early August, Teva told Bloomberg that the shortage was being caused by issues occuring at one manufacturing facility. The company warned at the time that these disruptions could lead to shortages going into the fall, which is what appears to have happened.

Many of Teva’s mixed amphetamine salts products are backordered, with most supplies not expected to be recovered until March 2023.