Hey guys,
I’m considering SC TRT. Most detailed & recent study I’ve found: Pharmacokinetic Profile of Subcutaneous Testosterone Enanthate Delivered via a Novel, Prefilled Single‐Use Autoinjector: A Phase II Study - PMC
Participants: 38 healthy men with hypo; AVG: 53 years old, 92 kg of weight, 178 cm of height (BMI = 29, obesity);
14 of them were treated with 50 mg SC TE 1/ew, 15 with 100 mg SC TE 1/ew, 10 with 200 mg IM TE 1/ew.
T AUC0>168h:
SC50 = 71k
SC100 = 150k
IM200 = 280k
SC100:SC50 = 2.13
IM200:SC100 = 1.85
T cAVG0>168h:
SC50 = 422
SC100 = 895
IM200 = 1660
SC100:SC50 = 2.12
IM200:SC100 = 1.85
(AUC reflection; conclusion: SC injection saves ~8% of the drug because of it’s slower TE release from the tissue, it’s logical if we look at SC’s t1/2 and AUC0>168h; both routes have the same BV basing on their AUC0>inf)
T cMAX:
SC50 = 622 (range 388 - 825)
SC100 = 1346 (624 - 2120)
IM200 = 2262 (787 - 4840)
SC100:SC50 = 2.17
IM200:SC100 = 1.7
(looking at AVG we could conclude that we’d get bigger T spike during SC, but when looking at ranges we assume that the difference is irrelevant = aromatization rate should be the same with SC100 and IM100)
T cMIN:
SC50 = 273 (182 - 372)
SC100 = 568 (236 - 860)
IM200 = 466 (203 - 780)
SC100:SC50 = 2.1
IM200:SC100 = 0.8
(2x higher cMIN with SC; conclusion: slower TE release with SC)
T tMAX was the same for both SC100 and IM200.
T t1/2:
SC50 = ND
SC100 = 10 days
IM200 = 7 days
(t1/2 is 30% higher with SC; conclusion: slower release of TE with SC)
DHT/T ratio was the same with SC50, SC100 and IM200.
E2 cAVG0>168h:
SC50 = 25.6 (E2:T 0.0063)
SC100 = 48.3 (0.0055)
IM200 = 50.0 (0.0032)
(it seems that aromatization is 2x more potent with SC)
Discussion:
SC route of the drug administration provides us obviously less pain & no muscle damage during injection, increased T t1/2 by 30% (so higher T cMIN) and the same: BV, T spikes, DHT/T ratio, T tmax. The depressing fact is 100 mg of TE SC produced the same level of E2 as 200 mg of TE IM. It’s 2x more!
Isn’t that irrational? Despite the longer t1/2 (which is obviously better considering aromatization) with SC, almost all PK parameters were the same. As we know aromatization rate is relatively high in fatty tissue, BUT the enzyme actually can’t convert enanthate ester to E2 before hydrolysis of the chemical bond what happen in the blood. I don’t see any serious reason for that E2 inconvenience.