I don't know firsthand -- I took exactly 1 chemistry class in college -- and I do hope one of the many less dangerously ignorant people in this thread will comment.Is there harm in using PTFE for water-based
It would maybe work in a pinch, as long as it's a hydrophilic membrane. I have read that PTFE is naturally hydrophobic so they have to coat it to be hydrophilic, whereas PES is naturally hydrophilic. PTFE also apparently exhibits higher protein binding than PES, so PES would definitely be better for protein based APIs.
My good buddy Claude.AI says the following, but keep in mind that I have to correct just about every AI on some deeply astounding errors in about 2-5% of the responses it gives. And those are just the errors I'm actually able to identify. The other day Claude based an entire page-long response regarding PIP around the premise that a 200mg/mL solution was less concentrated than a 100mg/mL solution.
Yes, you can use hydrophilic PTFE filters for water-based peptide/HGH solutions, and they work well for this application.
Hydrophilic PTFE for Peptides
Advantages:
Performance Considerations:
- Low protein binding - PTFE is relatively inert to proteins
- Excellent chemical resistance - Superior to most other membranes
- Compatible with BAC water - Benzyl alcohol won't affect PTFE
- Good flow rates once wetted properly
- Broad pH compatibility - Works across wide pH range
- Wetting: Requires proper priming with aqueous solution (may need gentle pressure initially)
- Protein recovery: Generally good, though PES may have slightly lower binding
- Durability: Very chemically stable, won't degrade
PES vs Hydrophilic PTFE for Peptides
PES remains the gold standard because:
Hydrophilic PTFE is excellent when:
- Naturally hydrophilic (easier wetting)
- Extensively characterized for protein applications
- Slightly lower protein binding in some studies
- More consistent batch-to-batch performance
- You need maximum chemical resistance
- Working with challenging pH conditions
- PES filters aren't readily available
- You're filtering multiple different solution types
Bottom Line
Hydrophilic PTFE filters will work very well for peptides/HGH in BAC water. While PES might have a slight edge in protein recovery, the difference is typically minimal for most applications. Choose based on availability and your specific needs.
Both are far superior to nylon or PVDF for peptide applications.

