Intramuscular vs SubQutaneous Injections for Testosterone

What do you mean by “Everything”? Please define. SQ and IM will have two distinct PK profiles for a given individual. Look at the scatter on TU plot in Fig. 1 above. SQ injection will have lower peak and higher trough than IM in general but same amount of T injected so AUC invariant to injection method.

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See below and TU paper above.

4 ml oil injection…i will pass:

The PK profile of serum testosterone and its two bioactive metabolites, DHT and E2 in this study indicate that the SC injections of TU displayed no significant differences from the IM route. This is consistent with PK studies of other steroids such as cortisol [19] and hydroxyprogesterone caproate [20] whereas in other studies the SC route displayed a lower and later peak serum concentration of progesterone [21] or medroxyprogesterone acetate [22]. Although Food and Drug Administration-defined bioequivalence was not formally tested, the two routes can be considered clinically comparable without the need for route-based dose adjustment. This interpretation differs from previous studies of SC injections which inferred a reduced testosterone dosage requirement by the SC route compared with the IM route [7, 10, 11] based on noncomparative studies of transgender men that did not investigate IM injections contemporaneously and relied upon historical data from other studies. Those studies used inconsistent, mostly single, sampling time points with the testosterone dosage being up-titrated according to clinical efficacy criteria, e.g., menstrual suppression [10], that may not represent effective virilization dosage for hypogonadal men [11].

Results

Fourteen transgender males (mean age, 30 ± 10 years) participated in the study. The mean hemoglobin values at the first and final visits were 160 ± 9 and 153 ± 9 g/L, respectively (p > 0.05); the mean ALT values were 18 ± 6 and 21 ± 10 IU/L (p > 0.05). Total testosterone exposure was comparable with subcutaneous versus i.m. injection (mean AUC, 1.7 ± 0.6 nmol·days/L/mg versus 1.9 ± 0.6 nmol·days/L/mg; p > 0.05). Information collected via weekly questionnaires indicated that the subcutaneous route was more tolerable, with lower self-reported scores for preinjection anxiety, pain during injection, and postinjection pain.

Conclusion

The subcutaneous route for the injection of testosterone was well tolerated and appeared to be as effective as i.m. injection in delivering equivalent TST levels, although there was wide intrapatient and interpatient variability.

Evidence Acquisition

Systematic review of available literature on SC testosterone administration including clinical trials, case series, and case reports. We also review the pharmacology of testosterone absorption after SC administration.

Evidence Synthesis

Available evidence, though limited, suggests that SC testosterone therapy in doses similar to those given via IM route results in comparable pharmacokinetics and mean serum testosterone levels. With appropriate training, patients should be able to safely self-administer testosterone esters SC with relative ease and less discomfort compared with the IM route.

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I started IM with “harpoons”, went to subQ using 27G. I then started pinning both subQ and IM to vary locations. I notice no difference if I jab subQ or IM for a month or switch it up.
I originally got large lumps in belly area although these seem to have stopped or greatly diminished. I’m guessing perhaps I was injecting the same area too frequently and causing a reaction.

I use test E for “TOT” but have mixed in mast, HCG and Deca in the same syringes in all areas with no noticable difference.

I pin twice a week, I doubt I’d feel much different just once but belive I’m leveling out my peak and troughs a tad and hopefully slightly less stress on my body (If it wouldn’t make much difference please let me know as saving 52 single use plastic syringes would make me happy).

I haven’t recent/useful bloods as I change stuff up as I feel but I’m looking for recovery from exercise as most other things are doing pretty good I’d say. (On 150mg a week, I don’t think I’d feel much on anything except possibly recovery if I lowered the dose slowly but it takes me all my will power to not raise it massively #issues!).
To answer questions;

  1. Do SubQ injections take a while to build up?

Don’t know (not a med pro or particularly smart guy).

  1. Why does SubQ seem to work for some but not for others?
    Sorry again I cant answer but perhaps they read too much?

  2. Best/least painful places to inject SubQ?
    Navel, love handle areas are not painful for me.

  3. Best/least painful places to inject IM?
    NEVER in the front of the quad! It can truly suck, anywhere else seems a better option. (ventrodorsal quad never hurts for me).

@tareload

The misinformation on here regarding IM vs SQ injections and resulting serum TT levels is staggering but understandable.

Tareload, you ever watch the BattleStar Gallactica remake? There was a saying repeated that I think apt,
“All this has happened before and will happen again…”

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Ecclesiastes 1:9 What has been will be again, and what has been done will be done again; there is nothing new under the sun. History merely repeats itself. It has all been done before. Nothing under the sun is truly new.

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ahhh gotya, thanks for clearing that up

100 mg/week of TC IM vs SQ

IM modeled as 4.5 day elimination half life and 8 hr absorption half life
SQ modeled as 8 day elimination half life and 16 hr absorption half life

E7D injections and typical clearance volume…

IM is orange and SQ is blue.

image

If you were only looking at trough TT value then you might mistakenly conclude you are getting better results with SQ.

Here’s the stats:

IM left / SQ right

image

Trough SQ / Trough IM = 1.28

Going back to above claim:

100 / 80 = 1.25

Mean TT on either protocol after reaching stable temporal profiles is ~ 1000 ng/dl.

TT tested at trough? Important to always define when your TT was tested in relation to injection timepoint if you want to make sense of any relative change in protocol.

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Yes, about 75 mg/week (twice a week) using parameters for IM in above post. So you are spot on given the variability in the PK parameters.

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I started with subq after being on cream. My dosage had my test high on my first testing so I reduced dosage but decided to try shallow IM to see if I noticed a difference. Feeling wise, did not notice a difference but next test with IM, even with a dose reduction, my levels went even higher than they were with subq. Possibly did not stick with subq long enough for a good comparison but do believe I was on for 3 months before testing. I saw the dosage reduction go higher with shallow IM and stuck with it as I saw it as a way to save money by not needing as much test versus subq. Personally I did not like subq either I found it more painful versus shallow IM.

For what it’s worth, the late Dr. John Crisler, who ran a TRT clinic in Lansing, Mi., ran his own informal experiments on his patients comparing sub-q to IM and found the former to result in higher total test. and less estradiol.

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Do you know if he released any articles or data about this? I found some videos, but nothing that would be considered ‘scientific literature’. No worries if not, just curious.

Yeah I had heard of his experiments and that is why I started sub-q versus IM. Like I said, I only ran sub-q for 3 months which was right after switching to injections over cream so maybe not a good comparison but my experience showed the opposite in both test levels and E2. Just my experience.

I am curious if he changed their protocol as well when he ran these experiments. Say a 2-3 times weekly IM, versus a daily sub-q? I personally did not change a thing and have been daily from day 1.

Doc told me to inject twice weekly or something similar when I was first moving to injections. Then I saw the harpoons he wanted me to do IM with and told him I wanted to try sub-q instead. If I was going to do that, he wanted me injecting daily. Made no sense to me why different injection methods I needed to do different injection protocols. Well except for, I sure as hell wouldn’t want to inject those harpoons daily. But saw no reason as to why sub-q couldn’t have been 2-3 times weekly over daily and now wondering if that is just how he read it works the best from these other experiments.

27/28g 0.5 inch insulin pin for IM/SQ/shallow IM/deep SQ :slight_smile:. DG or shoulder. Works for me.

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Same here. Delts is my usual go to, but occasionally throw in glute, lat, tri and quads. Got to mix things up a little :wink:

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Anyone know if there’s evidence to support increased effectiveness with more varied injection sites? Or perhaps the corollary with decreased effectiveness with lack of injection site variation?
IM or SubQ, doesn’t matter.

I don’t believe there is increased/decreased effectiveness personally. I just do it for minimizing potential scar tissue. Not real worried about it with small gauge needles, but just in case.

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Use for 10 min over site of injection. 256% effectiveness boost.

2nd device looks perfect for VG/DG.

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Higher trough and lower peak, almost like splitting your dose up during the week. Maybe just going SQ once a week is a way to mimic that?

I wonder if a certain amount of oil at a time will make a difference though due to muscle size and vascularity. Guessing that won’t really matter in the TRT range. Probably more when you start injecting 3 ml at a time.

What do you think of lats? Imo super underrated. Haven’t got pip once in a year of pinning EOD, sometimes 1mL at a time with a slin pin.

Pretty painless. I personally never have had to deal with PIP though, only pain during. Probably due to never injecting very large amounts being on a daily protocol, I would guess. I think the largest I have injected wasn’t even 1cc when I went hunting last year. I took a larger injection prior to going up so I didn’t have to worry about my test freezing and just left it at home.

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