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.

 

[MrsRoper_1977]

Nope. I do not filter.

 

[bbrewer]

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.

I don't believe that any where near 57% filter. I think those that do are much more likely to participate in a poll about it. Probably no way to get accurate numbers on that. I have all the stuff to do it, but don't feel the need. If I had a bad ISR like that it might motivate me to do it.

 

[scarywood75]

Ok what's up with these AI post? I wouldn't mind if they weren't bad lol

But first, I do filter, HOWEVER it is a misconception to say it makes your solution sterile.

Yeah it does remove potential harmful bacterias and fungal, but size doesn't matter here.

It will not remove small things (that can also kill ya), like :
- endotoxin
- viruses
- pyrogens

Also, you forget the air, sure you remove bacterias and fungal out of the solution, but if you add outside air in the vial, you ruined it a bit.

It is better to filter, rather than not doing it, but don't make it like it's the perfect and only needed sterile technique.

 

[Iamnew2this]

Nope. I do not filter.

Same. I really should, though.

 

[Super Trips]

I don't wear a mask in public why would i filter my peptides?

 

[nonyabizznez]

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.


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.

As someone who filters there's a lot of incorrect information here. We can start with "utterly critical" and then 13mm being "ideal" (like 4mm doesn't exist) and then move on to the ALL CAPS.

I can sum up why I filter in two words... Immuno compromised.

 

[rkl123]

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.

Great Heavens! So utterly critical!

(say myself who has been pepping for ~7 months without filtering and without issues)

 

[AndyPanda]

I don't wear a mask in public why would i filter my peptides?

Wearing a mask in public is a sign of submission to propaganda and mental illness. lol

 

[Calm Logic]

Wearing a mask in public is a sign of submission to propaganda and mental illness. lol

Or wearing a shirt that says "Peptide Test"

 

[AndyPanda]

Or wearing a shirt that says "Peptide Test"

I wonder how many he has sold?

 

[Calm Logic]

I'm guessing three.

 

[Augu5+1ne]

Hospira recommends against refrigeration because they want you to throw the bottle out after a single use. Refrigeration extends benzyl alcohol potency from about 28 days to 6weeks or more based in published studies. Syringe filtering grey market stuff is utterly critical to maintain safety from stray particles and bacterial contamination. You can get away with stabbing yourself with dirty needles many times, but eventually you’ll get the crud.

 

[Cndmk]

Filtering is essentially an insurance policy, is it most likely wasted money? Probably, is it possible that it can save your ass from potentially getting sick? Sure. What are the odds it saves you, probably below 1%.

My favorite concepts in math are cost/benefit analysis of insurance design, but in the world of insurance, it's going to be different than say an extended warranty, as the manufacturer's warranty generally has the highest occurrence of use vs. the extended warranty.

Why are extended warranties generally bad? You generally will pay around 10-20% of the item's value over the course of say 3X the length of the normal warranty. For electronics in particular, around 90-95% of defects in manufacturing occur as issues within the normal warranty period. In fact, if you make it past the first 6 months, odds are of the electronic failing are below 5% in the next 5-10 years of normal use. This also doesn't account for a depreciation asset cost, so the replacement cost of the item is most likely to be around the cost of the extended warranty in 5 years time.

I can dig up my source, but I worked in the semiconductor industry, and our 90 day quality testing mirrored these kinds of results (you can simulate humid/not fun temperate environments to speed up "aging" for electronics).


Let's look at filters and purely math:
Let's say we aim for 0.1% chance something is going to be funky in your vial that might cause you an adverse reaction that WOULD be filtered out (that is 1 in 1000 vials, probably not a crazy estimate).

For this situation, let's take a mid-range household salary for the US (around $60,000), and let's take a small illness (maybe like 2 days off of work because you feel like crap, not "I need to go to a clinic" crap, just "I can't work" crap)

Those 2 days vs. a roughly 200 days of work/year come out to 1% of your pay, or $600.

So how much does 1 filter cost? I would say around $1.50 looking around at prices (probably a little less in bulk)

Simple math here, 0.001(chance you got a bad vial)* $600(cost of lost work) = $0.60 of risk.

If the cost of risk > cost of the filter, then you should filter.

For myself, I err on the side of more conservative risk, so I would probably put like 0.25% chance instead of 0.1% chance because I'm a chicken, and I also make more than the average salary in the US, so for me, the cost of the risk is higher than the cost of the filter.

That was a fun validation of "Should I do Shit?". Stay tuned for the "Should I eat that?" math!

 

[AndyPanda]

This guy really likes the word “utterly.”