At this point I don’t know either. I just found out from a patient who was using BH4 online sometime ago, went back online to purchase and it disappeared. She contacted some of the compounding pharmacies that are often used and they are having a hard time getting it too.
I would suggest contacting Lee-Silsby and/or Hopewell Pharmacies to inquire about their current supply.
This happened a few years ago when DMSA was readily available as a supplement, then within a short period of time it disappeared from retail sales.
Dr. Woeller