There are two compounds that increase androgen receptor density. Androgen receptor density refers to how much testosterone is bound to the androgen receptor. When testosterone is bound to the receptor it can express its functions such as:
stimulating muscle hypertrophy
increasing libido
increasing aggression etc.
Carnitine
A study published in Medicine & Science in Sport & Exercise examined androgen receptor density between groups that supplemented with 2 grams of L-Carnitine L-Tartrate or placebo.(1) The group that supplemented with the Carnitine had increases in androgen receptor content in comparison to the placebo.
Tadalafil
Two studies have been done noting an increase in androgen receptor protein expression when using tadalafil (Cialis). One published in The Journal of Endocrinological Investigation and the other in Endocrine. (2,3) These results show why there may be an increase in libido with tadalafil separate of its action as a PDE5 inhibitor.
Conclusions
If you’re looking to increase the effectiveness of your testosterone for your workouts or health adding L-Carnitine L-Tartrate and/or getting a prescription for Tadalafil can help!
References:
Kraemer WJ, Spiering BA, Volek JS, et al. Androgenic responses to resistance exercise: effects of feeding and L-carnitine [published correction appears in Med Sci Sports Exerc. 2006 Oct;38(10):1861]. Med Sci Sports Exerc. 2006;38(7):1288-1296. doi:10.1249/01.mss.0000227314.85728.35
Aversa A, Fittipaldi S, Bimonte VM, et al. Tadalafil modulates aromatase activity and androgen receptor expression in a human osteoblastic cell in vitro model. J Endocrinol Invest. 2016;39(2):199-205. doi:10.1007/s40618-015-0344-1
Aversa A, Fittipaldi S, Francomano D, et al. Tadalafil improves lean mass and endothelial function in nonobese men with mild ED/LUTS: in vivo and in vitro characterization. Endocrine. 2017;56(3):639-648. doi:10.1007/s12020-016-1208-y