Considering thymalfasin therapy
Pharmacy rules desk
In compounding, a medicine is made or changed to suit one patient. As of September 28, 2026, thymosin alpha-1 does not meet the ingredient rules that let an ordinary pharmacy make medicine from raw material. The reasons are below.
A compounded medicine is one made or changed for a patient by a pharmacist, doctor or registered facility. This can help a patient when ready-made medicines do not meet their needs.
The Food and Drug Administration (FDA), which oversees US drugs, has not approved compounded medicines as of September 26, 2026. For these medicines, the FDA does not review whether they work, are safe or meet quality standards before they reach the market.
As of September 26, 2026, section 503A, the part of federal law for ordinary compounding pharmacies, sets out these ingredient checks in order:
The ingredient record
As of September 28, 2026, thymosin alpha-1 has no written drug standard that applies to it. No FDA-approved medicine contains it, and the list of allowed ingredients for ordinary pharmacies does not include it.
Read the FDA ingredient categoriesThe FDA also has a temporary list called category 1 while it reviews ingredients. Under its guidance, the FDA does not intend to act against pharmacies using those ingredients when all guidance conditions are met. This is a policy about enforcement, not a statement that the practice is lawful.
As of September 28, 2026, thymosin alpha-1 is not on that temporary list either. A pharmacy cannot rely on that policy to use it.
On the page from the FDA, current as of April 22, 2026, thymosin alpha-1 is listed under requests to add ingredients that were taken back. Its safety concerns are still printed beside the entry.
As of September 28, 2026, withdrawing that request neither permitted a pharmacy to use the ingredient nor placed it on the temporary category 1 list.
An outsourcing facility is registered with the FDA to prepare batches of sterile medicines. Sterile means free of germs. These facilities often supply clinics and hospitals.
As of September 28, 2026, the FDA’s separate list for these facilities puts thymosin alpha-1 in category 3. That means the request did not include enough information for the FDA to review it. This group is outside the temporary policy of not taking action, so a larger facility cannot rely on that policy to use it.