GPLC or Glycine-Propionyl L Carnitine since 2010 has been used by athletes or individuals involved in strength & resistance training to support healthy testosterone, GH & nitric oxide levels. GPLC supplements utilise an ester (another form) of propionyl L-carnitine; a naturally occurring form of L-carnitine within our bodies. L-carnitine is involved in transporting fats into our body’s fuel system in order to provide us with energy.
Unlike L-carnitine, GPLC has been reported in studies to have a number of beneficial functions within our body. GPLC may be able to:
- Combat Oxidative Stress – Through its ability to act as a powerful antioxidant within the body reducing peroxidation of lipids.
- Improve Endothelial Function – GPLC has been shown to exert a strong influence on nitric oxide levels; a molecule important for vasodilation of our blood vessels to offer potential performance enhancing ergogenic benefits.
- Offer Cardio-protective Effects – Due to GPLC’s strong affinity for cardiac muscle, it is excellent at increasing the carnitine content of cardiac muscle, more so than L-carnitine itself. Increased carnitine levels in the heart may provide a strong protective effect against metabolic and contractile issues.
- Help Insulin Resistance – Studies with GPLC have shown it may be effective in reducing weight, body fat, blood levels of insulin, as well as triglycerides in the liver – all of which are beneficial effects to combat the development of insulin resistance and diabetes.
- Enhance Energy Metabolism – GPLC also has a strong affinity for skeletal muscle and when taken as a supplement converts into L-carnitine and propionyl coenzyme A, both of which are involved in the metabolism of carbohydrates and lipids – effectively helping to increase the amount of ATP produced.
- Improve Erectile Dysfunction – A 2004 study by Cavallini et al examining GPLC on erectile dysfunction has reported it to be more beneficial than testosterone in improving certain symptoms of erectile dysfunction.
GPLC, like carnitine may cause side effects such as diarrhoea and nausea at high dosages. However keeping your dosages at between 4.5-9g/day appears to be a tolerable dose without any noticeable side effects. An acute dose of 4.5g is capable of producing beneficial effects during exercise, however strangely, lower doses of approximately 1.5g, are shown in studies to be more effective during longer term supplementation i.e 8-12 weeks.
GPLC Supplements are commonly presented & sold as Complementary Medicines, Registered Therapeutic Items or Goods and Formulated Supplementary Sports Foods in Australia. GPLC or glycine-propionyl L-carnitine is not a sole source of nutrition and should be used in conjunction with an appropriate physical training or exercise programme. Not suitable for children or pregnant women. Should only be used under medical or dietetic supervision. Always read the label prior to use.
1. Bloomer RJ, Smith WA, Fisher-Wellman KH. ‘Glycine propionyl-L-carnitine increases plasma nitrate/nitrite in resistance trained men.’ J Int Soc Sports Nutr. 2007 Dec 3;4:22. 2. Bloomer RJ, Tschume LC, Smith WA. ‘Glycine propionyl-L-carnitine modulates lipid peroxidation and nitric oxide in human subjects.’ Int J Vitam Nutr Res. 2009 May;79(3):131-41. 3. Smith WA, Fry AC, Tschume LC, Bloomer RJ. ‘Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance.’ Int J Sport Nutr Exerc Metab. 2008 Feb;18(1):19-36. 4. Jacobs PL, Goldstein ER, Blackburn W, Orem I, Hughes JJ. ‘Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males.’ J Int Soc Sports Nutr. 2009 Apr 2;6:9. 5. Jacobs PL, Goldstein ER. ‘Long-term glycine propionyl-l-carnitine supplemention and paradoxical effects on repeated anaerobic sprint performance.’ J Int Soc Sports Nutr. 2010 Oct 28;7:35. 6. GPLC Patent. ‘http://www.google.com/patents/about?id=MkoRAAAAEBAJ&dq=6703042’ Last accessed 12th January 2012 7. Mingorance C, Rodriguez-Rodriguez R, Justo ML, Herrera MD, de Sotomayor MA. ‘Pharmacological effects and clinical applications of propionyl-L-carnitine.’ Nutr Rev. 2011 May;69(5):279-90. doi: 10.1111/j.1753-4887.2011.00387.x. 8. Cavallini G, Biagiotti G, Koverech A, Vitali G. Oral propionyl-l-carnitine and intraplaque verapamil in the therapy of advanced and resistant Peyronie's disease. BJU Int 2002;89:895-900.