Image Map

Carnitine MoleculeIf you use a testosterone booster, prohormone or anabolic steroids to help increase muscle mass and intensity in the gym, you need to know about the benefits of L-Carnitine L-Tartrate!  This simple nutrient can add major improvements to the ability of the body to use testosterone and other steroid hormones.  Every person should be taking a carnitine supplement if they are bodybuilding!


L-Carnitine is an amino acid that is involved in many biological processes in the body.  Mainly, it helps with proper fat metabolism, which is why it was traditionally given to people who were cutting.  More recent knowledge shows that it is involved in many processes that effect the brain, energy and even sexual health of men.  Carnitine can be found in a normal diet and is especially high in red meat.  Still, it is often bound to other amino acids and incorporated into muscle opposed to being used as a supplement.


Carnitine can help synthesize more testosterone by assisting in the conversion of cholesterol to other hormones and ultimately testosterone.  In addition Carnitine has been shown to protect the testicles from damage due to high cholesterol levels (1) and also damage from radiation (2).  This shows an overall protective effect, which can translate into protection from steroids and other chemicals in the diet.

Carnitine can also protect and normalize sperm count and sexual performance (3) along with improving mood and overall general well being (4).  For older men in particular, L-Carnitine has been shown to improve mood and reduce fatigue which is very important for anyone over 30 who is into bodybuilding.

Carnitine has also been shown to help with endurance by preferentially allowing the body to use fat stores for energy opposed to going to the muscle glycogen (5).  This both spares the muscle from fatigue and additionally helps with fasted cardio for those that wish to burn more fat!  (which is all of us)

When cutting, Carnitine can spare muscle mass and reduce catabolic states, which helps precontest to reduce the loss of mass when doing an extreme cut!


The big benefit of LC-LT (L-Carnitine L-Tartrate) is when combined with steroids such as testosterone.  Two studies show that LC-LT can impact hormones that increase muscle growth.  One study shows an increase in IGF-BP3 along with LC-LT, which is a signaling molecule that increases growth and reduces damage from exercise (6)  Carnitine has also been shown improve anabolic pathways in general.

Another, more impressive study shows that LC-LT helps with testosterone (and presumably other steroids) uptake and androgen receptor content and reduced LH shut down (7).  This has major implications for men using testosterone boosters, prohormones and anabolic steroids.  Better utilization of steroids is the holy grail of anyone who has ever taken courses of steroids, prohormones or test boosters.

If you want to get more out of each cycle consider supplementing with a good L-Carnitine product that includes L-Carnitine L-Tartrate like Carnisport from APS.


  1. Drug Res (Stuttg). 2014 Oct;64(10):510-5. doi: 10.1055/s-0033-1361176. Epub 2013 Dec 10.
    CoQ10 and L-carnitine attenuate the effect of high LDL and oxidized LDL on spermatogenesis in male rats.
    Ghanbarzadeh S1, Garjani A2, Ziaee M3, Khorrami A4.
  2. Acta Histochem. 2014 Jul;116(6):1046-55. doi: 10.1016/j.acthis.2014.04.010. Epub 2014 Jun 9.
    L-carnitine protects against testicular dysfunction caused by gamma irradiation in mice.
    Ahmed MM1, Ibrahim ZS2, Alkafafy M3, El-Shazly SA4.
  3. Urology. 2004 Apr;63(4):641-6.
    Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging.
    Cavallini G1, Caracciolo S, Vitali G, Modenini F, Biagiotti G.
  4. Physiol Behav. 2008 Oct 20;95(3):341-7. doi: 10.1016/j.physbeh.2008.06.012. Epub 2008 Jun 29.
    Effect of inhibiting carnitine biosynthesis on male rat sexual performance.
    Dambrova M1, Cirule H, Svalbe B, Zvejniece L, Pugovichs O, Zorenko T, Kalvinsh I, Liepinsh E, Belozertseva I.
  5. Biochem Biophys Res Commun. 2015 Aug 21;464(2):568-73. doi: 10.1016/j.bbrc.2015.07.009. Epub 2015 Jul 8.
    L-Carnitine enhances exercise endurance capacity by promoting muscle oxidative metabolism in mice.
    Kim JH1, Pan JH1, Lee ES1, Kim YJ2.
  6. J Strength Cond Res. 2003 Aug;17(3):455-62.
    The effects of L-carnitine L-tartrate supplementation on hormonal responses to resistance exercise and recovery.
    Kraemer WJ1, Volek JS, French DN, Rubin MR, Sharman MJ, Gómez AL, Ratamess NA, Newton RU, Jemiolo B, Craig BW, Häkkinen K.
  7. Nutr Metab (Lond). 2013 Mar 15;10(1):28. doi: 10.1186/1743-7075-10-28.
    Supplementation of carnitine leads to an activation of the IGF-1/PI3K/Akt signalling pathway and down regulates the E3 ligase MuRF1 in skeletal muscle of rats.
    Keller J1, Couturier A, Haferkamp M, Most E, Eder K.