Clinical perspective, offered as context rather than as advice.

GMP compliance checklist relevant to compounded supply compounding quality:

• Clean room environment with HEPA filtration
• Environmental monitoring (viable and non-viable)
• Personnel training and competency assessment
• Validated analytical methods for testing
• Stability testing program
• Complete batch records and traceability
• Quality management system with deviation handling

A 503B pharmacy following cGMP should be able to answer questions about ALL of these if you ask. Don't be afraid to ask — it's your health.

Dr.NephBHM_UK said:

GMP compliance checklist relevant to compounded supply compounding quality: Clean room environment with HEPA filtration Environmental monitoring…

This is my experience too, for whatever a second data point is worth. Posting only so the count is not one.

Dr.NephBHM_UK said:

GMP compliance checklist relevant to compounded supply compounding quality: Clean room environment with HEPA filtration Environmental monitoring…

Compounding pharmacy response time test for compounded supply: I email customer service at odd hours to test responsiveness. A pharmacy that can't answer questions promptly is a red flag.

My current pharmacy: average response time 1 hour. They answered my questions about batch-specific COAs thoroughly and professionally.

Communication quality is a proxy for operational quality. A pharmacy that communicates well is likely manufacturing well too.

Dr.NephBHM_UK said:

GMP compliance checklist relevant to compounded supply compounding quality: Clean room environment with HEPA filtration Environmental monitoring…

Compounding pharmacy red flag checklist for compounded supply — if ANY of these apply, find a different source:

1. No verifiable physical address
2. No pharmacist available for consultation
3. COA not available or clearly template/fake
4. Prices dramatically below market ($30-40/month = suspicious)
5. No prescription required
6. Ships without cold pack or temperature control
7. No batch/lot numbers on product labeling
8. Pushes "research use only" products for human injection

Your health depends on product quality. Don't cut corners on source verification.

A narrower follow-up, since the general answer is now clear:

What did you change at the same time, and can you separate the two now?