Bac water/peptide ratio

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ultima thule

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Just wondering how to manage higher concentration peptides per vial. As I understand the common rule is to add 1-2 ml of bac water per 10mg of compund. It is easy, when we deal with 10mg or 20mg vials. For example we add 1ml to 10mg and if we inject 2mg, we just pin 20 units of 1ml syringe. But if we have for example 40mg vial and we add maximum 3ml of bac water and we want to pin 10mg it is 60 units - quite a lot. But on the other hand bac water/peptide ratio is less than 1ml per 10g. And now I got 2 wrinkles...what's the maximum dose of solution we can inject subcutaneously at once? And is it any hassle to reconstitute peptide in a less than 1ml of bac water per 10mg?
 
A reverse calculator may help:

Reverse Peptide Calculator

I usually use 2-3 mL of BAC, unless it's a spicy / stingy peptide like NAD+ or glutathione that I dilute more. There's also other exceptions, like the peptide VIP that can have very small doses like 50 mcg (0.05 mg).

Generally, for non-stingy peptides, I aim for about 20 units (0.2 mL) per dose to help with measuring correctly. The insulin syringes go up to 30 units (0.3 mL), 50 units (0.5 mL), and 100 units (1 mL), so those all seem like safe amounts for subq.
 
ultima thule said:
As I understand the common rule is to add 1-2 ml of bac water per 10mg of compund.

This is the part that's not true, and a lot of the remaining confusion is solved with "there's no actual common rule that applies to all peptides." The "how much" is "it varies."

I like to keep my pins at 35 units or less and no fewer than 10 units when I can. There are peps that are too site-reactive for that, but I don't use most of them. I used to recon KLOW very weak, talking 12 ml to 70mg of ghk-cu, but I did okay with this last one at 3 ml to 50 mg, guessing because the rest of it was better balanced than my overfilled kits.

I have some 7.5 mg (were supposed to be 10 but tested underfilled) vials of Epitalon; when I recon it, since it's a 20 day cycle, I use 2.25 ml to recon three vials and filter into a single pen cartridge, because my dose is 1 mg per day for 21 days, and my units-per-pin are 10.

Tirz, I recon at 22 mg/ml, because that was the concentration my original Brello-acquired compound vials came at, and I just never changed it.
 
So another question is: does the concentration matter or not? Is it safe to reconstitute 40mg of Reta in 2ml of bac water?
 
ultima thule said:
So another question is: does the concentration matter or not? Is it safe to reconstitute 40mg of Reta in 2ml of bac water?
You could inject gallons of BAC water and be alright (or at least far more than one would think). So you don't have to worry about being too dilute.

And for reta/tirz, a concentration of 20 mg per mL would be fine, as said by @randompersonrandom with the tirz concentration from Brello Health. Reta wouldn't be any different.
 
I'm doing R60 next. I'll add 2ml BAC and at 7mg a pin, it'll be a 2.3mg shot. Should be a tad over 8 doses a vial, perfect. I'm going to do 2 ml BAC now that the pin mg are higher. Better than the 7-8mg pins. Easier to draw from the vial too. I'll do this with my R30mg too.
 
Alright guys gotcha. So eventually concentration is not a case. Only a matter when we talking about some particular peps, which are considered as a sting ones, regarding a comfort only...
 
ultima thule said:
Just wondering how to manage higher concentration peptides per vial. As I understand the common rule is to add 1-2 ml of bac water per 10mg of compund. It is easy, when we deal with 10mg or 20mg vials. For example we add 1ml to 10mg and if we inject 2mg, we just pin 20 units of 1ml syringe. But if we have for example 40mg vial and we add maximum 3ml of bac water and we want to pin 10mg it is 60 units - quite a lot. But on the other hand bac water/peptide ratio is less than 1ml per 10g. And now I got 2 wrinkles...what's the maximum dose of solution we can inject subcutaneously at once? And is it any hassle to reconstitute peptide in a less than 1ml of bac water per 10mg?
I recon, transfer into a larger vial (say 5ml) snd then add mote BAC water. For example if I have a 3ml vial of 50mg GHK, i will recon with 2.5ml of BAC, transfer and filter into a 5ml sterile vial and then add an additional 2.5ml for a total dilution of 5ml.
 
ultima thule said:
Alright guys gotcha. So eventually concentration is not a case. Only a matter when we talking about some particular peps, which are considered as a sting ones, regarding a comfort only...
yea i would say it really all depends on how much bac water you are trying to inject and as well how much you would like to dilute the peptide, like an other user above said, for some “spicy” peps. Me personally I went with 2 ml for tesa since that one also stings but I reckon the location you pin is also a factor.
 
ultima thule said:
Alright guys gotcha. So eventually concentration is not a case. Only a matter when we talking about some particular peps, which are considered as a sting ones, regarding a comfort only...

I not sure that it's safe to characterize peptide concentration as only a matter of comfort.

As far as your specific question about tirzepatide at 40mg/2mL, that's clearly fine since Lilly provides tirzepatide in 15mg/.5mL vials which of course is 30mg/mL, which is more concentrated than Brello's 22mg/mL. So, we have "precedent"that 30mg/mL is safe. So, reconsituting at 20mg/mL is clearly okay.

I think it's an open question at which concentration is too high. And it might vary across peptide. For example, could you physically reconstitute that 40mg vial of tirzepatide with .5mL of bac? Probably. But that would result in an 80mg/mL concentration. Or a 60mg vial with .5mL of bac, would result in 120mg/mL. I'm not sure if either of these concentrations is a great idea. It will be interesting to see what Lilly does if it eventually goes to market with higher doses of tirzepatide.

Some peptides such as semaglutide and cagrilintide are more prone to aggregation at higher concentrations. So with those, I wouldn't push the upper end of the concentration spectrum.

Semaglutide would appear safe up to 9.6mg/mL with the new higher dose. NN kept the same amount of mL per pen (made the brew more concentrated), but it's still a relatively weak concentration.

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Grogu said:
I not sure that it's safe to characterize peptide concentration as only a matter of comfort.

As far as your specific question about tirzepatide at 40mg/2mL, that's clearly fine since Lilly provides tirzepatide in 15mg/.5mL vials which of course is 30mg/mL, which is more concentrated than Brello's 22mg/mL. So, we have "precedent"that 30mg/mL is safe. So, reconsituting at 20mg/mL is clearly okay.

I think it's an open question at which concentration is too high. And it might vary across peptide. For example, could you physically reconstitute that 40mg vial of tirzepatide with .5mL of bac? Probably. But that would result in an 80mg/mL concentration. Or a 60mg vial with .5mL of bac, would result in 120mg/mL. I'm not sure if either of these concentrations is a great idea. It will be interesting to see what Lilly does if it eventually goes to market with higher doses of tirzepatide.

Some peptides such as semaglutide and cagrilintide are more prone to aggregation at higher concentrations. So with those, I wouldn't push the upper end of the concentration spectrum.

Semaglutide would appear safe up to 9.6mg/mL with the new higher dose. NN kept the same amount of mL per pen (made the brew more concentrated), but it's still a relatively weak concentration.

View attachment 21889
Actually I was about Reta, but I see we going the same direction. Wondering if there's any suggested concentration pattern for a particular peptides. And does it make any difference what concentration final solution has. Is some sort of concentration more stable, got a potentially longer shelf life, or maybe even is more or less efficient, etc... Didn't find any research regarding that issue, hence this thread.
 
One thing to consider that I haven't seen mentioned yet is that the more concentrated the peptide, the more precise you need to be with loading the syringe. Small variations in volume can yield larger variance in dosage.
 
ultima thule said:
Actually I was about Reta, but I see we going the same direction. Wondering if there's any suggested concentration pattern for a particular peptides. And does it make any difference what concentration final solution has. Is some sort of concentration more stable, got a potentially longer shelf life, or maybe even is more or less efficient, etc... Didn't find any research regarding that issue, hence this thread.
For grey, where we are just trying to avoid a hospital visit one day, I would go with more BAC than less BAC, if anything. More BAC is better for preventing aggregation of the peptide (more room for the reta) and could help with having more preservative.
 
Calm Logic said:
For grey, where we are just trying to avoid a hospital visit one day, I would go with more BAC than less BAC, if anything. More BAC is better for preventing aggregation of the peptide and could help with having more preservative.
You're making me re-think my 2ml vs 3ml logic now damn it. 🤣
 
ultima thule said:
Actually I was about Reta, but I see we going the same direction. Wondering if there's any suggested concentration pattern for a particular peptides. And does it make any difference what concentration final solution has. Is some sort of concentration more stable, got a potentially longer shelf life, or maybe even is more or less efficient, etc... Didn't find any research regarding that issue, hence this thread.

Lilly has not publicly disclosed the precise concentration of the retatrutide solution used in the TRIUMPH trials in the way that approved drugs have their formulations in prescribing information. Since retatrutide is not FDA approved the full formulation specifications remain proprietary and unpublished. I agree with @Calm Logic err on the side of more bac than less bac.
 
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