Testosterone Injections Increase Muscle and Strength Better than T gels

[Nelson Vergel]

J Cachexia Sarcopenia Muscle. 2018 Mar 15. doi: 10.1002/jcsm.12291. [Epub ahead of print]


Muscular responses to testosterone replacement vary by administration route: a systematic review and meta-analysis.

Skinner JW

Abstract

BACKGROUND:
Inconsistent fat-free mass (FFM) and muscle strength responses have been reported in randomized clinical trials (RCTs) administering testosterone replacement therapy (TRT) to middle-aged and older men. Our objective was to conduct a meta-analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route.



METHODS:
Systematic literature searches of MEDLINE/PubMed and the Cochrane Library were conducted from inception through 31 March 2017 to identify double-blind RCTs that compared intramuscular or transdermal TRT vs. placebo and that reported assessments of FFM or upper-extremity or lower-extremity strength. Studies were identified, and data were extracted and validated by three investigators, with disagreement resolved by consensus. Using a random effects model, individual effect sizes (ESs) were determined from 31 RCTs reporting FFM (sample size: n = 1213 TRT, n = 1168 placebo) and 17 reporting upper-extremity or lower-extremity strength (n = 2572 TRT, n = 2523 placebo). Heterogeneity was examined, and sensitivity analyses were performed.

RESULTS:
When administration routes were collectively assessed, TRT was associated with increases in FFM [ES = 1.20 ± 0.15 (95% CI: 0.91, 1.49)], total body strength [ES = 0.90 ± 0.12 (0.67, 1.14)], lower-extremity strength [ES = 0.77 ± 0.16 (0.45, 1.08)], and upper-extremity strength [ES = 1.13 ± 0.18 (0.78, 1.47)] (P < 0.001 for all). When administration routes were evaluated separately, the ES magnitudes were larger and the per cent changes were 3-5 times greater for intramuscular TRT than for transdermal formulations vs. respective placebos, for all outcomes evaluated. Specifically, intramuscular TRT was associated with a 5.7% increase in FFM [ES = 1.49 ± 0.18 (1.13, 1.84)] and 10-13% increases in total body strength [ES = 1.39 ± 0.12 (1.15, 1.63)], lower-extremity strength [ES = 1.39 ± 0.17 (1.07, 1.72)], and upper-extremity strength [ES = 1.37 ± 0.17 (1.03, 1.70)] (P < 0.001 for all). In comparison, transdermal TRT was associated with only a 1.7% increase in FFM [ES = 0.98 ± 0.21 (0.58, 1.39)] and only 2-5% increases in total body [ES = 0.55 ± 0.17 (0.22, 0.88)] and upper-extremity strength [ES = 0.97 ± 0.24 (0.50, 1.45)] (P < 0.001). Interestingly, transdermal TRT produced no change in lower-extremity strength vs. placebo [ES = 0.26 ± 0.23 (-0.19, 0.70), P = 0.26]. Subanalyses of RCTs limiting enrolment to men ≥60 years of age produced similar results.

CONCLUSIONS:
Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength in middle-aged and older men, particularly in the lower extremities.

 

[keithc2485]

As for using androgel 100mg qd , after 2 years of 100mg IM every week, will those results be lost from the 2 years? and will the gel continue to sustain me at all if used properly and working out everyday?

 

[Dakeri]

This confirms what bodybuilders have known for years. they always inject they dont mess with gels.

 

[madman]

This confirms what bodybuilders have known for years. they always inject they dont mess with gels.

The reason bodybuilders inject is it allows one to attain supra-physiological testosterone levels well above what a transdermal could ever do!

Most men using/abusing testosterone for the sole purpose of gaining muscle/increasing strength have testosterone levels in the 2000+ ng/dl range and even than amateur/professional bodybuilders may be as high as the 5000-10 000 ng/dl range.

 

[FeelingLost]

I am very surprised once the T in in your blood the body would respond differently.

 

[madman]

I am very surprised once the T in in your blood the body would respond differently.

One would also need to see the different total t/free t levels reached by each patient on average using im vs transdermal.

Transdermal method also mimics the natural circadian rhythm of a healthy young male where levels peak in the am and gradually decline later in the day as oppose to im which in no way mimics the natural circadian rhythm as even though there are still fluctuations using im method high levels are still present am/pm.

I would say steady state higher testosterone levels achieved by im method are responsible for increased gains muscle/strength vs transdermal.

Would like to see a study which compares im vs transdermal using a dose morning and evening (applied dose in the am and pm) which would allow user to achieve higher testosterone levels day/night.

 

[S1W]

I would say steady state higher testosterone levels achieved by im method are responsible for increased gains muscle/strength vs transdermal.

Using the same logic, do you think it's safe to assume that the results of this study could be extrapolated to SubQ injections?

 

[madman]

Using the same logic, do you think it's safe to assume that the results of this study could be extrapolated to SubQ injections?

Absorption/effectiveness of testosterone im vs sub-q should make no difference!

The only difference is sub-q is injected into adipose where the oily depot forms before being released and im is injected into muscle where the oily depot forms before being released.

 

[Ricardo Braido]

Dear, For three months I have been injecting testosterone 250 mg (Durateston) intramuscularly every 15 days.Last week I took saliva 10 days after the last injection and the results were as follows: T = 39 pg / ml (the ideal is 80 to 200 pg / ml) and estradiol <0.6 pg / ml (the ideal is 1.7 to 3.4 pg / ml).
Why did my testosterone and estradiol lower even while injecting testosterone? (The recommendation of the Durateston package insert, which is a mixture of four testosterone esters, is applied every 15 to 20 days). What happened?
Thank you!

 

[Nelson Vergel]

Responses of different doses of testosterone injections on body composition, strength, etc.