The U.S. Food and Drug Administration announced it is proposing to exclude semaglutide, tirzepatide, and liraglutide from the 503B bulks list, stating it found no clinical need for outsourcing facilities to compound these drugs from bulk substances.

The 503B bulks list identifies bulk drug substances that outsourcing facilities may use in compounding under section 503B of the Federal Food, Drug, and Cosmetic Act. Outsourcing facilities generally cannot compound drugs using bulk drug substances unless the substance appears on this list or the compounded drug is on the FDA's drug shortage list.

After evaluating nominations for the three substances, the FDA determined there was insufficient clinical need for outsourcing facilities to compound these medications from bulk drug substances.

"When FDA-approved drugs are available, outsourcing facilities cannot lawfully compound using bulk drug substances unless there is a clear clinical need," said FDA Commissioner Marty Makary. "This action reflects our responsibility to protect patients and preserve the integrity of the drug approval process."

The agency stated it reviewed nominations and did not identify sufficient evidence to include the three drugs on the 503B bulks list. Clinical need determinations are based on patient safety and medical necessity requirements under federal law.

The FDA is accepting public comments electronically through June 29, 2026, before making a final determination on the proposal.