IM Testosterone More Effective than Transdermal in Increasing Mass and Strength

A new meta-analysis looks at the studies on fat free mass and strength gains from TRT and finds a difference in results depending on how it is administered. Intramuscular injection was 3-5 times more effective than transdermal application in increasing fat free mass (FFM) and strength.

When administration routes were collectively assessed, TRT was associated with increases in FFM, total body strength, lower-extremity strength, and upper-extremity strength. When administration routes were evaluated separately, the 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 and 10–13% increases in total body strength, lower-extremity strength, and upper-extremity strength. In comparison, transdermal TRT was associated with only a 1.7% increase in FFM, and only 2–5% increases in total body and upper-extremity strength. Interestingly, transdermal TRT produced no change in lower-extremity strength vs. placebo. Subanalyses of RCTs limiting enrolment to men ?60 years of age produced similar results.

The full text of the article can be read online
 

hCG Mixing Calculator

HCG Mixing Protocol Calculator

TRT Hormone Predictor Widget

TRT Hormone Predictor

Predict estradiol, DHT, and free testosterone levels based on total testosterone

⚠️ Medical Disclaimer

This tool provides predictions based on statistical models and should NOT replace professional medical advice. Always consult with your healthcare provider before making any changes to your TRT protocol.

ℹ️ Input Parameters

Normal range: 300-1000 ng/dL

Predicted Hormone Levels

Enter your total testosterone value to see predictions

Results will appear here after calculation

Understanding Your Hormones

Estradiol (E2)

A form of estrogen produced from testosterone. Important for bone health, mood, and libido. Too high can cause side effects; too low can affect well-being.

DHT

Dihydrotestosterone is a potent androgen derived from testosterone. Affects hair growth, prostate health, and masculinization effects.

Free Testosterone

The biologically active form of testosterone not bound to proteins. Directly available for cellular uptake and biological effects.

Scientific Reference

Lakshman KM, Kaplan B, Travison TG, Basaria S, Knapp PE, Singh AB, LaValley MP, Mazer NA, Bhasin S. The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men. J Clin Endocrinol Metab. 2010 Aug;95(8):3955-64.

DOI: 10.1210/jc.2010-0102 | PMID: 20534765 | PMCID: PMC2913038

Beyond Testosterone Podcast

Online statistics

Members online
4
Guests online
692
Total visitors
696

Latest posts

Back
Top