SubQ? Intranasal? Topical?

laansasa

laansasa

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I got to wondering why certain peps/aminos have to go SubQ and aren't suitable for intranasal or topical use. From what I read, it comes down to molecular weight.

- Below 500 daltons: topical absorption works well.

- Below 1000 daltons: the nasal mucosa can take it up (intranasal bioavailability).

- Above 1000 daltons: subQ is the only option.

Since I couldn't locate a cheat sheet or chart covering most peps, I put this one together. I'm not a scientist, so treat it as a simple and "recreational" reference only.

Suggestions for edits are welcome. I'm sure a few are missing - I just grabbed a vendor's price list and used whatever was on it.

Hopefully it helps those of you who, like me, want to understand the reasons behind things and would rather not search for one pep at a time online.
 
laansasa said:

I got to wondering why certain peps/aminos have to go SubQ and aren't suitable for intranasal or topical use. From what I read, it comes down to molecular weight.

- Below 500 daltons: topical absorption works well.

- Below 1000 daltons: the nasal mucosa can take it up (intranasal bioavailability).

- Above 1000 daltons: subQ is the only option.

Since I couldn't locate a cheat sheet or chart covering most peps, I put this one together. I'm not a scientist, so treat it as a simple and "recreational" reference only.

Suggestions for edits are welcome. I'm sure a few are missing - I just grabbed a vendor's price list and used whatever was on it.

Hopefully it helps those of you who, like me, want to understand the reasons behind things and would rather not search for one pep at a time online.
Click to expand...
Alright, anyone up for turning orange? Putting 5 amino on the skin? I'll skip that
 
CNCCurrency said:

laansasa said:

I got to wondering why certain peps/aminos have to go SubQ and aren't suitable for intranasal or topical use. From what I read, it comes down to molecular weight.

- Below 500 daltons: topical absorption works well.

- Below 1000 daltons: the nasal mucosa can take it up (intranasal bioavailability).

- Above 1000 daltons: subQ is the only option.

Since I couldn't locate a cheat sheet or chart covering most peps, I put this one together. I'm not a scientist, so treat it as a simple and "recreational" reference only.

Suggestions for edits are welcome. I'm sure a few are missing - I just grabbed a vendor's price list and used whatever was on it.

Hopefully it helps those of you who, like me, want to understand the reasons behind things and would rather not search for one pep at a time online.
Click to expand...
Alright, anyone up for turning orange? Putting 5 amino on the skin? I'll skip that
Click to expand...
LMAO!😂😂😂 Around here, plenty of blue skin is happening...yet intranasal GHK-Cu is something I just can't picture...Ouch 😬
 
I wouldn't put much stock in that oversimplified rule of thumb. Sure, lower molecular weight compounds tend to cross barriers such as the skin or nasal mucosa more readily, but lipid solubility matters just as much. If something is polar and doesn't dissolve well in fats, it won't penetrate the skin. Take glucose: m.w. 180, yet skin absorption is minimal. As for peptides, essentially none will pass through intact skin unless you bring in specialized delivery systems such as microneedles. On the other hand, larger proteins can be taken up intranasally — insulin, m.w. 5800 daltons, is an example. I haven't done an exhaustive literature dive, but my hunch is that no peptide is going to make it across the skin.
 
lessthanhalf said:

I wouldn't put much stock in that oversimplified rule of thumb. Sure, lower molecular weight compounds tend to cross barriers such as the skin or nasal mucosa more readily, but lipid solubility matters just as much. If something is polar and doesn't dissolve well in fats, it won't penetrate the skin. Take glucose: m.w. 180, yet skin absorption is minimal. As for peptides, essentially none will pass through intact skin unless you bring in specialized delivery systems such as microneedles. On the other hand, larger proteins can be taken up intranasally — insulin, m.w. 5800 daltons, is an example. I haven't done an exhaustive literature dive, but my hunch is that no peptide is going to make it across the skin.
Click to expand...
When it comes to ghk-cu and ahk-cu, topical application gives great results, but as for the rest, I haven't given them a try.
 
lessthanhalf said:

I wouldn't put much stock in that oversimplified rule of thumb. Sure, lower molecular weight compounds tend to cross barriers such as the skin or nasal mucosa more readily, but lipid solubility matters just as much. If something is polar and doesn't dissolve well in fats, it won't penetrate the skin. Take glucose: m.w. 180, yet skin absorption is minimal. As for peptides, essentially none will pass through intact skin unless you bring in specialized delivery systems such as microneedles. On the other hand, larger proteins can be taken up intranasally — insulin, m.w. 5800 daltons, is an example. I haven't done an exhaustive literature dive, but my hunch is that no peptide is going to make it across the skin.
Click to expand...
I'm with you on that — my goal wasn't to give people a dosing protocol to follow, just to offer a rough sense of the reasoning behind why certain peps get delivered one way versus another. Over in other places, I've run into plenty of people asking whether they can go intranasal rather than subQ with peps that are simply too big for that route. Spreading wrong info is not what I'm after. If it came across that way, I'm sorry. That's on me.
 
GHK-cu and similar compounds do have positive human clinical trial results for skin effects, and from what I understand it's believed to be effective when applied topically — so it has to be crossing the skin. I believe microinjection testing was done as well. That means a small number of peptides can penetrate the skin, not zero. As for injecting it subcutaneously, there's no evidence at all.
 
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