I've written before about how subcutaneous (under the skin) injections are more convenient and less problematic than intramuscular injections for men undergoing testosterone replacement therapy (TRT).
I described how the cumulative damage to poking your muscle(s) over and over again for a couple of decades is bound to leave your glutes, quads, or delts (the typical IM delivery sites) with the consistency of beef jerky. SubQ injections, however, don't cause scarring to the muscle.
Accordingly, subQ injections also cause less pain and irritation than IM shots. You can also use the same needle to fill your syringe and administer the dose when going subQ and you don't even need to aspirate.
I also suggested – without providing much substantiation – that subQ shots may be more potent than IM shots in that they might lead to higher total testosterone levels than their meat-piercing alternative.
Now, however, courtesy of the Department of Urology at University of California, we have clinical evidence of how subQ shots lead to higher levels of free T, along with evidence of them being physiologically superior to IM shots in several other important ways.
The researchers wanted to compare four effects, or potential effects, of subQ and IM injections:
- Total testosterone levels
- Hematocrit levels – The ratio of red blood cells to total volume of blood; if it's too high, you're at a heightened risk of heart attack or stroke.
- Estradiol levels – Generally speaking, you don't want too much of your testosterone to be aromatized into estradiol.
- PSA levels – High levels of PSA are implicated with prostate cancer.
In order to conduct those comparisons, the researchers recruited 232 men. Baseline levels were measured and then were repeated at 6 weeks and 12 weeks post-treatment.
Men who received subQ injections of testosterone exhibited the following:
- 14% greater total testosterone levels than those receiving IM injections.
- 41% lower hematocrit that those receiving IM injections.
- 26.5% lower estradiol than those receiving IM injections.
- No rise in PSA (the IM method didn't raise PSA either).
Based on this simple study, there's not much reason for men undergoing TRT to use IM. In fact, it's plain silly to continue with this antiquated method.
If you want to make the switch, buy yourself some 25 gauge, half-inch needles or 26 gauge, 3/8-inch needles and some 1 cc syringes. There are several diabetes care websites that ship direct to the customer.
Ideally, split your normal weekly dosage into two equal doses. In other words, if you normally inject 100 to 200 mg. of testosterone every week, inject 25 mg. or 50 mg. of your 200 mg/ml testosterone cypionate or testosterone enanthate prescription (the most common formulation in the U.S.) twice a week, e.g, Tuesday and Friday.
To administer the testosterone, wipe the top of the bottle of testosterone ester (cypionate and enanthate are basically equivalent) with an alcohol swab.
Then draw up the pre-determined dosage of testosterone with your insulin syringe and simply "dart" the needle into the fat layer over your abs, into the "love handles," or into pretty much any damn fatty area you please (it doesn't make much difference where you shoot). Inject the testosterone slowly.
Given that the subQ method leads to a higher total testosterone level (and presumably higher levels of bioavailable testosterone), you might want to adjust your dosage downwards. Then again, you might just want to ride the higher levels and see how you do.
- Choi EJ et al. Comparison of Outcomes for Hypogonadal Men Treated with Intramuscular Testosterone Cypionate versus Subcutaneous Testosterone Enanthate. J Urol. 2022 Mar;207(3):677-683. PubMed.