Do You Filter Your Peptides Before Use?

[zpped]

Apparently you are not supposed to filter peptides with GHK in them, does anyone know more about this ?

Opinions ?

Why would you not. Ask whoever told you that to explain what the problem is?

 

[deleted.user.18]

The article quoted seems to warn about the TB and BPC, not the GHK.

"When solution first contacts the membrane, it can cause a local pH drift of ±0.2–0.4 units — sufficient to denature or partially unfold sensitive peptides such as BPC-157 or TB-500."

OK so let’s reason on this with what we find with a quick scholarly article search. Instead of making assumptions on how far down the rabbit hole my search has gone. Now I’m not a chemist or scientist or even a holiday inn express guest. But we have some of the most complete online scholarly source libraries and the most powerful search tools we’ve ever had access to.

1) BP-157 is not a sensitive peptide, it is widely described in literature as a stable gastric pentadecapeptide because it is native to gastric digestive juices. If BPC-157 can withstand hours in an environment that is several pH units lower than a neutral buffer, it is highly improbable that a localized, temporary drift of a mere 0.2 to 0.4 units in a buffered preparation would be sufficient to cause denaturation or unfolding. (Seiwerth, S., et al. (2021). Stable Gastric Pentadecapeptide BPC 157 and Wound Healing. Frontiers in Pharmacology, 12, 627533; Sikiric, P., et al. (2014). The Stable Gastric Pentadecapeptide BPC 157 Pleiotropic Beneficial Activity and Its Possible Relations with Neurotransmitter Activity. Molecules, 17(4), 461–481)

2) TB-500 is typically used as the synthetic fragment Ac-LKKTETQ, consisting of only four to seven amino acids. Denaturation and unfolding refer to the disruption of complex structures, which are characteristic of large proteins. Small fragments like TB-500 lack the intricate three-dimensional folds that would be susceptible to denaturation by a minor pH change. TB4 is however fairly unstable from what I’ve read and this is why almost all research is done with the fragment TB500. (Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential-Simone Espositoa, Koen Deventera, Jan Goemanb, Johan Van der Eyckenb, Peter Van Eenooa)

3) The premise that a pH drift will occur and damage the product is typically nullified by standard pharmaceutical preparation practices, which require the use of proper buffers. The pH drift from filtration is transitory and happens briefly as the media is wetted. Now, normally in high quality pharma peptides they use a buffered solution to handle exactly this type of drift… we are probably not getting that type of product. TFA used to purify the petite may add to the pH problem. (Guideline on the Development and Manufacture of Synthetic Peptides. European Medicines Agency (EMA), Draft Guideline) However, as described in the literature above BPC-157 and TB500 have low susceptibility to denaturing even without a buffer.

4) Not having considered that the material I’ve read is likely referencing higher quality buffered peptides, I revisited the susceptibility of unbuffered GHK-Cu and KPV to filtration and pH drift. GHK-Cu is

stable at pH 4 to 7.5, but dissociation occurs at pH below 4, so testing pH prior to filtration could show you if you have room for the drift without damaging it. Apparently any TFA residual could cause the reconstituted solution to have a very low pH (GLOW/KLOW burn anyone?) which means it could be damaged even before filtering. KPV also a small peptide so now worries about denaturing, but attains a positive charge at pH below 7 so if the filter media has a negative charge it could selectively increase loss due to absorption. (https://www.researchgate.net/figure...ys-Pro-diketopiperazine-formed_fig4_266679185 ; https://pmc.ncbi.nlm.nih.gov/articles/PMC5498804/ ) I guess it seems reasonable to conclude that filter would negatively impact KPV and GHK-Cu. GHK-Cu in an unbuffered lyophilized powder with TFA residuals is already damaged if the reconned solution pH is below 4.

Again I not an expert by any means, but I can research read and reason ok. Those are my findings so far.

 

[deleted.user.18]

The article seems to FIND reasons you haven't: " In short Filtering KLOW offers no biochemical benefit and carries several downsides — you risk losing active peptide, destabilizing GHK-Cu, and even reducing shelf life."

So for now even not knowing the article's source it still resonates an air of sound rationale behind a reason to not filter KLOW. ( If it was created properly ).

But hey, what do I know? I'm just a kindergartner in Peptide school. I'll believe most anything.

It’s not an article. It’s a Reddit post with citations that do not directly corroborate its conclusions. But the thought that grey market peptides may be lyophilized with an emphasis on purity but not on stability (ie no buffers) was one I hadn’t considered in all of my reading. The post makes some interesting claims worth investigating. Primarily for me is pH testing my reconned solutions since there may be no buffer.

 

[zpped]

(GLOW/KLOW burn anyone?)

The GLOW burn is certainly not PH based as many people have tested and confirmed the PH before experiencing it. The most likely culprit is free copper in the solution, as evidenced by other members showing that the burn can be neutralized by mixing in GHK-basic that would bind to the free copper.

We've been PH testing reconstituted peptides for a long time and almost everything is fine excluding most NAD as it requires a substantial buffer to make bearable and only PGB makes it that way last I knew.

 

[deleted.user.18]

The GLOW burn is certainly not PH based as many people have tested and confirmed the PH before experiencing it. The most likely culprit is free copper in the solution, as evidenced by other members showing that the burn can be neutralized by mixing in GHK-basic that would bind to the free copper.

We've been PH testing reconstituted peptides for a long time and almost everything is fine excluding most NAD as it requires a substantial buffer to make bearable and only PGB makes it that way last I knew.

Do you find the pH lands somewhere between 6.0-7.0? Do you have any evidence that the solution is buffered? From what I’ve read even GHK-Cu when buffered is not going to be pushed out of the 4-7.5 by filtering.

 

[juGGaKNot]

Why would you not. Ask whoever told you that to explain what the problem is?

The first 2 points refer to it i guess

1. Adsorption to filter membranes. peptides can bind to the membrane via hydrophobic interactions, hydrogen bonding, or electrostatic attraction.This leads to peptide losses of 5–25 %, especially for small, basic peptides like GHK-Cu, which has multiple positively charged amino groups.

Sources: Atha & Ingham, J. Chromatogr. A (1981); Ahern & Klibanov, Science (1985)⸻

2. Metal chelate instability. Result: loss of active GHK-Cu, visible color change (bluish → colorless), and reduced biological activity.

Sources: Pickart & Thaler, J. Inorg. Biochem. (1973); Maquart et al., Biochim. Biophys. Acta (1993)

I haven't notices color change last time i reconned GLOW.

The text says "CAN" everywhere, not "will" so i wanted to ask.

 

[zpped]

The first 2 points refer to it i guess

1. Adsorption to filter membranes. peptides can bind to the membrane via hydrophobic interactions, hydrogen bonding, or electrostatic attraction.This leads to peptide losses of 5–25 %, especially for small, basic peptides like GHK-Cu, which has multiple positively charged amino groups.

Sources: Atha & Ingham, J. Chromatogr. A (1981); Ahern & Klibanov, Science (1985)⸻

2. Metal chelate instability. Result: loss of active GHK-Cu, visible color change (bluish → colorless), and reduced biological activity.

Sources: Pickart & Thaler, J. Inorg. Biochem. (1973); Maquart et al., Biochim. Biophys. Acta (1993)

I haven't notices color change last time i reconned GLOW.

The text says "CAN" everywhere, not "will" so i wanted to ask.

1) what filter membrane material were they using 1985? PES is specifically designed not to bind to proteins. (this would also be an issue for every peptide, not just ghk-cu)

2) This is pretty easy to demonstrate as false. You can filter ghk-cu through 10 filters in a row and not see color change.

 

[PinkSlippers]

Thank you so much for this tip. Order placed for filters. Appreciate users like yourself that dig into some research to help us all. Top class contribution in my humble opinion. Could I please ask what in your opinion a good fridge life for reconstituted Retatrutide is, ie is 3 months too long

Thank you for sharing this information. Very very helpful!

 

[OldManStrength]

I was just watching a podcast by Vigorous Steve and he stated that some of the amino acids that make up peptides are to large for a .22 micron filter, i would love to see a reference for amino acid size compared to .22 micron filters.

 

[desinr-gal]

I was just watching a podcast by Vigorous Steve and he stated that some of the amino acids that make up peptides are to large for a .22 micron filter, i would love to see a reference for amino acid size compared to .22 micron filters.

I dont think any mentioned in common use here are that big.. the subject would have been addressed by now. I read that Peptides that have aggregated would be too big, as would peps not fully dissolved when reconstituting, which I can attest to. Allowing 20 minutes rest will help with that.