Dr Justin Saya MD
Moderator
Wanted to drag over a discussion from the FB group so it doesn't get lost in the FB black hole (as Nelson calls it) for all of time and perhaps can enlighten folks for more than a few days. A member posted the following (copy/paste so hopefully formatting cooperates):
I switched to daily SubQ injections at 140mg per week. I was previously injecting IM on MWF at 140mg per week. Here are the shocking results:
IM:
Testosterone,Free and Total 1151 ng/dL 348 - 1197
Free Testosterone(Direct) 20.4 pg/mL 7.2 - 24.0
SubQ:
Testosterone,Free and Total 1500 ng/dL 348 - 1197
Free Testosterone(Direct) 44.3 pg/mL 7.2 - 24.0
Various members went on to discuss and postulate why this may occur. It's important to note that for the MWF injection routine, the patient had labs on Mon (after last injection Friday- no injection Sat, Sun, or Mon prior to lab draw). The daily SC lab draw was on the day after a daily SC injection (prior to the next injection).
My response (again copy/paste so forgive if formatting acts funky):
This is very common with DAILY injections, regardless of if it's SC or IM. Most folks don't have the desire or wherewithal to stick to a daily injection routine in the LONGterm without developing "injection fatigue" or becoming noncompliant. For those that can (and actually WANT to inject daily), they can often (with a few exceptions for unique cases) get away with lower cumulative weekly dosages than folks who do once weekly, twice weekly, or even three times weekly injections. Again, this happens with both SC and IM (I have seen both) and is really a factor of the frequency of injections more than the location/technique of injections.
The complicated reasoning is due to the pharmacological parameter of TERMINAL half life, accumulation, and steady state. In simplest terms, T cyp does not reach a TRUE steady state with once weekly, twice weekly, or three times weekly dosages (although twice weekly and three times weekly come close enough for our purposes, but there is STILL variation). On the other hand, daily injections, at least pharmacologically speaking, are capable of achieving a TRUE steady state (even less fluctuation than BIW/TIW) and consequently can often use smaller dosages. Now this comes with the obvious trade off of poking yourself 365 times per year vs 156 (three times weekly) vs 104 (twice weekly)...in the real world and clinical practice, the subjective/symptomatic difference usually isn't large enough to outweigh the increased hassle (except for a select few). Hope this isn't too complex or technical, but hope it helps with understanding! Indeed an interesting phenomenon.
I switched to daily SubQ injections at 140mg per week. I was previously injecting IM on MWF at 140mg per week. Here are the shocking results:
IM:
Testosterone,Free and Total 1151 ng/dL 348 - 1197
Free Testosterone(Direct) 20.4 pg/mL 7.2 - 24.0
SubQ:
Testosterone,Free and Total 1500 ng/dL 348 - 1197
Free Testosterone(Direct) 44.3 pg/mL 7.2 - 24.0
Various members went on to discuss and postulate why this may occur. It's important to note that for the MWF injection routine, the patient had labs on Mon (after last injection Friday- no injection Sat, Sun, or Mon prior to lab draw). The daily SC lab draw was on the day after a daily SC injection (prior to the next injection).
My response (again copy/paste so forgive if formatting acts funky):
This is very common with DAILY injections, regardless of if it's SC or IM. Most folks don't have the desire or wherewithal to stick to a daily injection routine in the LONGterm without developing "injection fatigue" or becoming noncompliant. For those that can (and actually WANT to inject daily), they can often (with a few exceptions for unique cases) get away with lower cumulative weekly dosages than folks who do once weekly, twice weekly, or even three times weekly injections. Again, this happens with both SC and IM (I have seen both) and is really a factor of the frequency of injections more than the location/technique of injections.
The complicated reasoning is due to the pharmacological parameter of TERMINAL half life, accumulation, and steady state. In simplest terms, T cyp does not reach a TRUE steady state with once weekly, twice weekly, or three times weekly dosages (although twice weekly and three times weekly come close enough for our purposes, but there is STILL variation). On the other hand, daily injections, at least pharmacologically speaking, are capable of achieving a TRUE steady state (even less fluctuation than BIW/TIW) and consequently can often use smaller dosages. Now this comes with the obvious trade off of poking yourself 365 times per year vs 156 (three times weekly) vs 104 (twice weekly)...in the real world and clinical practice, the subjective/symptomatic difference usually isn't large enough to outweigh the increased hassle (except for a select few). Hope this isn't too complex or technical, but hope it helps with understanding! Indeed an interesting phenomenon.
