Optimal units per injection

I usually land in that same range too. Sometimes I mix it so the dose is only 10-15 units.

20-30 units is my preference as well. For some twice-daily peptides with small doses like 125-250mcg I set the mix so it fits evenly into one or two 3mL cartridges. Since I pin them often I'm okay with a unit being slightly off. Once I used a weak concentration for a 1mg dose and kept it when going to 3mg, but at 4mg that meant 72 units so I split it into two 36 unit injections as the pen stops at 60. I'll go stronger next time.

This is an interesting discussion. For GLP-1s it's mostly about comfort since they last a long time in the body. But other peptides might have their effectiveness changed by how diluted they are. Tesamorelin especially has a short half life of about 30 minutes and can form aggregates more in stronger solutions, which might lower purity and raise chances of immune issues. Also the volume affects how much gets into the blood at peak. Maybe some of the peptides we use have similar issues.

I've been thinking about the same thing. I try to add the smallest amount of BAC when mixing, but perhaps the goal should be the opposite and use more. That's a good point.

It's a balance. Some sources suggest going for the highest dilution to cut down on clumping, and steering clear of big vials like 20 mg that sit around long enough for gelling to become a problem. At the same time, one newer formulation at 8 mg per ml works just as well as the older 1 mg per ml version even at a lower amount. It relies on a special additive to stop clumping though. My middle ground is using 10 mg vials mixed with 2 ml of the usual bac water. So far the results on my bloodwork look good and there has been no sign of reaction or gelling.

I normally mix my tirz at 0.5 mg per unit so the numbers stay simple while I adjust the dose. For the rest I go with a stronger mix, meaning fewer units each time, so I do not have to mix fresh as often. One example is my custom blend from the 100 mg vials of GHK-Cu plus 20 mg of the other components in 2.5 ml bac water, which gives 5 units per dose.

For me anything up to 50 units feels normal. The only thing I inject at 1 ml is Nad+, and pulling that much cold liquid through a 31 g needle is awkward. I have some 29 g needles left over and they make it easier. I also do 1.5 ml of Gluta but that goes IM so the needle size is not an issue.

I track everything in mg per ml so the volume changes with the dose and it is harder to get the amount wrong. With tirz I have been running 10 mg per ml. Since I split into two shots a week I might keep that strength up to 15 mg. Right now that is 0.55 ml or 55 units per dose and next weekend it will be 0.6 ml. The brand pen version uses the same 0.6 ml.

At first I mixed with the least bac water possible to keep the injection volume small. It turned into a pain trying to read the tiny marks on the syringe at 5 in the morning.

I keep concentrations on the lower side to reduce the chance of clumping, especially with amylin agonists. I aim for somewhere between 20 and 80 units per shot. I do not work backward from the target unit count when figuring the mix volume though. I prefer to keep the math straightforward and usually end up at 10, 20, or 30 mg per ml, with 20 mg per ml being the usual for tirzepatide. I have helped a relative with her weekly shots using the brand pens and even those make me uneasy for smaller amounts. Several times I have dialed to 9 clicks, put the syringe in, pressed, nothing came out, then dialed back and suddenly a much larger amount came out. I am not sure why it happens but it has occurred more than once, which is why I generally stay away from pens.

Yes. For vials that will be used with syringes I always add 3 ml or a bit more for the reason already noted. Higher concentrations with saline bac water have definitely caused gelling or clouding. One time I mixed an R10 vial with 3 ml saline bac water and it stayed perfectly clear. I did get temporary gelling though when I tried the same volume with an R50 vial.

In general I aim for 0.05 to 0.3 ml per dose. Measuring 0.05 ml in a 0.3 ml syringe is straightforward because of the markings. Those 0.3 ml syringes are the ones I reach for most often. When I started I read that larger volumes can feel uncomfortable and some people said 0.5 to 1 ml was unpleasant. My biggest single shot is 2 ml or 200 units once a week and that is just how it comes. The 2 ml volume does not bother me.

Right now I do three different shots each week. Two of them are 0.3 ml and the tirz is 0.5 ml for 15 mg. I like to stay between 0.25 and 0.5 ml when possible. When I was doing glutathione it was 1 ml for 600 mg but that was IM.

There is plenty of useful information here. My own approach is different. I do not worry much about how many units the shot ends up being. What matters to me is that every peptide I am using has the same injection volume for its dose. All of mine are currently 10 units: 10 for ghk-cu, 10 for reta, 10 for cjc/ipa, and so on. Working it out this way makes stacking much simpler because I can fill the syringes without checking notes or thinking about it. I like 10 units because the bac water lasts longer. If I ever stop stacking as many I will probably increase the volume and dilute more. I want to finish the bac water within a comfortable time frame so I am not tempted to keep using it past that point.