Abstract (Research Summary)
- Tyrosine is a precursor of dopamine, norepinephrine, epinephrine, and thyroid hormones.
- L-Tyrosine in combination with capsaicin, catechins, and caffeine increases 4-hour thermogenesis (by 90 kJ) and daily energy expenditure by ~200 kJ (2%), resulting in ~7 kg (~15 lbs) weight loss and fat mass reduction over 8 weeks (Belza 2007, Belza 2005).
Tyrosine (aka 4-hydroxyphenylalanine) is a non-essential amino acid used in the synthesis of certain neurotransmitters including dopamine, norepinephrine and epinephrine, as well as thyroid hormones thyroxine and triiodothyronine (Rosebrough 1994).
L-Tyrosine Effects on Weight Reduction
L-Tyrosine alone is not shown to promote weight loss in most human studies. However, including L-Tyrosine in combination therapies may help induce weight loss through the activation of sympathetic system and increased thermogenesis.
- L-Tyrosine in combination with capsaicin, catechins, and caffeine increases 4 hour thermogenesis (by 90 kJ), resulting in ~7 kg (~15 lbs) weight loss and fat mass reduction over 8 weeks (Belza 2007).
- L-Tyrosine in combination with capsaicin, catechins, caffeine, and calcium increases daily energy expenditure by ~200 kJ (2%) (Belza 2005).
Dopamine, Norepinephrine, and Epinephrine Effects on Weight Reduction
L-Tyrosine is a precursor for dopamine and norepinephrine, which may help to promote weight loss through increased body activity and thermogenesis and decreased appetite.
- L-Tyrosine is a precursor for dopamine and norepinephrine. These transmitters may help to promote weight loss through increased body activity and thermogenesis (Billes 2008, Gadde 2007).
- Increasing dopamine and norepinephrine in obese animals increases body activity and thermogenesis and decreases food intake, resulting in weight reduction (Billes 2007).
- Increasing dopamine, norepinephrine, and serotonin can inhibit food intake and increase thermogenesis, resulting in 4% to 7% weight loss in 1 year (Gomis Barbará 2004).
- Dopamine increase through L-Tyrosine stimulates catabolic pathways, promoting weight loss (Mancini 2006).
- Norepinephrine and dopamine may exert appetite-suppressing effects (Halford 2001).
- Belza, A., Frandsen, E., Kondrup, J. (2007). Body fat loss achieved by stimulation of thermogenesis by a combination of bioactive food ingredients: a placebo-controlled, double-blind 8-week intervention in obese subjects. International Journal of Obesity (Lond), 31 (1), pp. 121-30. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16652130 [Accessed 24.08.2016].
- Belza, A., Jessen, A. (2005). Bioactive food stimulants of sympathetic activity: effect on 24-h energy expenditure and fat oxidation. European Journal of Clinical Nutrition [online], 59 (6), pp. 733-41. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15870822 [Accessed 24.08.2016].
- Billes, S., Cowley, M. (2008). Catecholamine reuptake inhibition causes weight loss by increasing locomotor activity and thermogenesis. Neuropsychopharmacology [online], 33 (6), pp. 1287-97. Available from: http://www.nature.com/npp/journal/v33/n6/full/1301526a.html [Accessed 24.08.2016].
- Billes, S., Cowley, M. (2007). Inhibition of dopamine and norepinephrine reuptake produces additive effects on energy balance in lean and obese mice. Neuropsychopharmacology [online], 32 (4), pp. 822-34. Available from: http://www.nature.com/npp/journal/v32/n4/full/1301155a.html [Accessed 08.24.2016].
- Gadde, K., Xiong, G. (2007). Bupropion for weight reduction. Expert Reviews of Neurotherapeutics [online], 7 (1), pp. 17-24. Available from: http://www.ncbi.nlm.nih.gov/pubmed/17187492 [Accessed 24.08.2016].
- Gomis Barbará, R. (2004). Pharmacological treatment of obesity. Revista de Medicina de la Universidad de Navarra [online], 48 (2), pp. 63-5. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15382615 [Accessed 24.08.2016].
- Halford, J. (2001). Pharmacology of appetite suppression: implication for the treatment of obesity. Current Drug Targets [online], 2 (4), pp. 353-70. Available from: http://www.ncbi.nlm.nih.gov/pubmed/11732637 [Accessed 25.08.2016].
- Mancini, M., Halpern, A. (2006). Investigational therapies in the treatment of obesity. Expert Opinion on Investigational Drugs [online], 15 (8), pp. 897-915. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16859393 [Accessed 25.08.2016].
- Rosebrough, R. (1994). Nutritional effects on neurotransmitter metabolism in the broiler chicken. Comparative Biochemistry and Physiology [online], 107 (3), pp. 573-80. Available from: http://www.ncbi.nlm.nih.gov/pubmed/7909739 [Accessed 24.08.2016].
This research was sponsored by GLOBESITY FOUNDATION (nonprofit organization) and managed by Don Juravin. GLOBESITY Bootcamp for the obese is part of GLOBESITY FOUNDATION which helps obese with 70 to 400 lbs excess fat to adopt a healthy lifestyle and thereby achieve a healthy weight.
Tags: l-tyrosine, weight reduction, GLOBESITY FOUNDATION, weight loss, cravings, diabetes, healthy weight