Do You Filter Your Peptides Before Use?

[Peptelligence]

Hey everyone,

I've been diving deep into peptide handling protocols lately and wanted to start a discussion about something that seems simple but could make a huge difference in your research: Do you filter your reconstituted peptides before use, or do you use them as is?

Why This Matters:
For those just getting started with peptides, filtering might seem like an extra, unnecessary step. However, it's actually crucial for several reasons:

• Safety First: Unfiltered peptides may contain bacteria, particulate matter, or manufacturing residues that could cause infection, inflammation, or adverse reactions when used in research settings.
• Protecting Your Investment: Quality peptides aren't cheap! Using them without proper filtration is like buying premium fuel for your car but pouring it through a dirty funnel. You're compromising what you paid for.

The Real Value:
When you filter your reconstituted peptides through a proper 0.22 μm syringe filter, you're:

• Removing potentially harmful bacteria and particles that could cause injection site reactions or infections
• Maximizing the purity of your product, which directly translates to more reliable outcomes
• Protecting yourself from potential contaminants introduced during manufacturing or shipping

Beginner-Friendly Best Practices:
If you're new to this, here's what you need to know:

What to Buy:

• Get sterile 0.22 μm syringe filters (PES/Polyethersulfone filters are best as they don't absorb your peptides)
• Make sure you have sterile syringes to use with the filters
• Consider the volume you'll be filtering (smaller 4mm filters for under 4ml, larger 13mm filters for more)

Simple Process:

1. Draw your reconstituted peptide into a sterile syringe
2. Attach the filter to the syringe
3. Slowly push the liquid through the filter into your sterile storage vial
4. Label appropriately with contents and date

Remember that filtering is not just a "nice to have" but a fundamental step that separates proper research protocols from potentially dangerous shortcuts. The small investment in filters (usually $1-2 each) provides enormous value in terms of safety.

Has anyone here experienced noticeable differences between filtered and unfiltered peptides (especially with overseas purchases)? Or perhaps you've always filtered but weren't sure why it matters? I'd love to hear your experiences!

 

[Skidude]

This is an interesting discussion and there is a great deal of feedback as well as a poll here:

Post in thread 'To filter or not to filter, that is the question'

Apr 4, 2025

What do you all mean by filter?

It's a process where you run your solution through a filter attached to the end of a syringe. The idea is a small enough filter to catch bacteria but not peptides.

• brentm

 

[Augu5+1ne]

I was shocked to see that only 57% of vote casters filtered their peptides. It is indeed utterly critical to syringe filter your grey market peptides.

0.22micron 13mm diameter sterile PES filters are ideal because they will filter 99.9% of bacteria of concern (but not viruses or endotoxins!), yet allow the much smaller 4.9kDA retatrutide molecule through. The smallest bacteria are about 200nm which is like 600k kDA size! Syringe filtering really leverages this size difference to give you a relatively bacteria-free product to inject much more safely.

Personal story: when I first tried "pinning" myself with Polaris's peptides, I gave myself cellulitis (redness, heat, tenderness, indurated region of about 10x6cm directly at the site of injection) which I had to treat with 5days of antibiotics. I thought I had just broken sterile procedure, so the next week I went extra hard on using lots of new alcohol swabs on rubber tops, on my skin, marked my skin pinning site w/marker etc. Within 24hrs I got another hard, red, hot site of cellulitis and again I had to treat myself with antibiotics to clear it. I blamed Polaris for likely contaminated product and thought about contacting them to complain, but then realized the fault was mine for not filtering the products. Ever since then SYRINGE FILTERING ABSOLUTELY for everything and problems solved.

It's not expensive to get "sterile" 25gauge needles, 3ml syringes (all with luer lock tips), and these PES 0.22 filters from various places and very easy to do - it should be part of the routine for ALL OF US HERE. Also you must make sure to use sterile <3month old 0.95 benzyl alcohol containing bacteriostatic sterile water REFRIGERATED ALWAYS, and new sterile needles, syringes, and plentiful alcohol swabbing of all surfaces to maximize clean/"sterile" procedures. I think all these things should be initially daunting, but eventually easy to learn for all of us.

 

[AndyPanda]

I was shocked to see that only 57% of vote casters filtered their peptides. It is indeed utterly critical to syringe filter your grey market peptides.

0.22micron 13mm diameter sterile PES filters are ideal because they will filter 99.9% of bacteria of concern (but not viruses or endotoxins!), yet allow the much smaller 4.9kDA retatrutide molecule through. The smallest bacteria are about 200nm which is like 600k kDA size! Syringe filtering really leverages this size difference to give you a relatively bacteria-free product to inject much more safely.

Personal story: when I first tried "pinning" myself with Polaris's peptides, I gave myself cellulitis (redness, heat, tenderness, indurated region of about 10x6cm directly at the site of injection) which I had to treat with 5days of antibiotics. I thought I had just broken sterile procedure, so the next week I went extra hard on using lots of new alcohol swabs on rubber tops, on my skin, marked my skin pinning site w/marker etc. Within 24hrs I got another hard, red, hot site of cellulitis and again I had to treat myself with antibiotics to clear it. I blamed Polaris for likely contaminated product and thought about contacting them to complain, but then realized the fault was mine for not filtering the products. Ever since then SYRINGE FILTERING ABSOLUTELY for everything and problems solved.

It's not expensive to get "sterile" 25gauge needles, 3ml syringes (all with luer lock tips), and these PES 0.22 filters from various places and very easy to do - it should be part of the routine for ALL OF US HERE. Also you must make sure to use sterile <3month old 0.95 benzyl alcohol containing bacteriostatic sterile water REFRIGERATED ALWAYS, and new sterile needles, syringes, and plentiful alcohol swabbing of all surfaces to maximize clean/"sterile" procedures. I think all these things should be initially daunting, but eventually easy to learn for all of us.

You are not supposed to refrigerate bacteriostatic water.

 

[dogmom]

I actually bought a bunch of supplies to filter a few months ago but have never done it yet.

 

[flsailfish22]

I don't filter my reconstituted peptides, but I will add some extra BA sometimes. The BA is what's going to safeguard you more than filtering from bacteria. I do filter the stuff I homebrew. Filtering is really more for particles/materials than could have fallen into the solution and BA it to make sure there is no bacteria. Filtering does add an extra layer of safety which isn't a bad thing. The type and size of filter listed is spot on the best way to go if you are going to start filtering your peptides.

As for refrigerating BAC. Hospira recommends against refrigeration even when opened. I however do refrigerate after opening. Hospitals don't refrigerate it either, but like I said above sometimes I will add a little more BA to make it like 1% instead of .9% for a little extra safety. Also, BAC is cheap. Don't use shit Amazon BAC. Buy Hospira BAC. I personally have like 20 3ml bottles at all times. If I really doubt something I just throw it away to lower risk.