Using L-tyrosine for weight loss may support increased energy and metabolism. However, there are no clinical research studies that have looked at the effects of Tyrosine on fat loss or diet.
There are anecdotal reports of effectiveness, but user reviews show that the supplement is typically used in combination with diet and exercise.
For this reason, it is difficult to determine what the specific effect of L-tyrosine for weigh loss is.
Supplementing with L-tyrosine may promote an increase in energy levels and motivation. This could support weight loss efforts. This supplement is reported to increase motivation to work out as well as enhancing athletic performance.
L-tyrosine is a precursor to dopamine, adrenaline, noradrenaline and both T3 and T4 thyroid hormones. It is used to diminish overactive appetite, alleviate depression, treat fatigue, improve sleep, manage stress, and regulate hormones.
Usage of L-tyrosine supplements is rated as likely safe, even when taking high dosages.



- Supports energy & motivation
- Promotes focus & mental clarity
- Improves mood & stress response
What is L-Tyrosine?
Related Topics
L-tyrosine is one of more than twenty amino acids which the body uses to form proteins. It is non-essential, meaning that the body can manufacture it.
L-tyrosine was first isolated by a German chemist named Justus von Liebig in 1846. He discovered it when exploring the protein casein found on cheese. The Greek word “tyros” means cheese.
L-tyrosine occurs naturally in certain foods; including nuts, seeds, sprouts, fish, fowl, bananas, avocados, legumes – and cheese.
In the body, the primary role for this amino acid is as the chemical precursor to dopamine. Dopamine is an excitatory neurotransmitter that is connected to mood, feelings of pleasure, focus, mental energy, executive performance that the reward feedback loop. Dopamine also plays a role in regulating muscular movement.
L-tyrosine is frequently used to improve mood and promote mental performance.
This supplement has also been used to treat ADHD (attention deficit hyperactivity disorder), alleviate PMS (premenstrual syndrome) symptoms, ameliorate Alzheimer’s and Parkinson’s symptoms, reduce risks of cardiovascular disease, treat erectile dysfunction (ED), improve libido, decrease expressions of schizophrenia symptoms, increase melanin, retain skin elasticity and reduce withdrawal symptoms of alcohol and cocaine.
L-Tyrosine and Weight Loss
There is no direct clinical evidence which demonstrates L-tyrosine’s capacities to induce weight loss. However, there is evidence that it may affect factors related to obesity, heart health, diabetes and more.
More specifically, using L-tyrosine for weight loss may help to:
- Improve the mood and decrease depressive episodes which may affect weight gain;
- Reduce blood pressure, especially in times of stress;
- Decrease the perceptions of acute stressors, helping to diminish stress-related weight gain;
- Increasing subjective well-being;
Supplementing L-tyrosine may also help to increase energy metabolism, reduce physical and mental fatigue and improve alertness. These may have indirect effects on weight loss. However, it is unlikely that taking L-tyrosine on its own will have any effect on fat loss.
If you intend to use this supplement as part of a weight loss plan, it is important to incorporate a healthy diet and exercise program. Other supplements may aid in achieving results, including 5-HTP which is reported to reduce appetite by increasing serotonin levels in the brain.
L-Tyrosine Effects on the Thyroid
L-Tyrosine may support weight loss by increasing the activity of the thyroid. Low thyroid hormone levels (hypothyroidism) is very common among individuals who are obese or overweight.
When the thyroid gland is underactive, metabolic function may be negatively affected. The thyroid gland is often referred to as the “master gland” because it is largely responsible for hormonal balancing throughout the body.
Women, and men, with underactive thyroids may experience a variety of symptoms including:
- Fatigue and/or slow heart rate;
- Slowness of speech and/or hoarseness of voice;
- Goiter (swollen neck) that results from thyroid inflammation:
- Excessive sensitivity to cold temperatures;
- Constipation and/or headaches;
- Developing hair that is dry, coarse and/or scaly;
- Depression, dementia and/or confusion;
- Menstrual issues;
- Chronic fatigue;
- Weight gain
L-Tyrosine is necessary for thyroid hormones to be synthesized in the body. In individuals with hypothyroidism, a dosage of 500 mg per day has been recommended to improve thyroid function. This is theorized to support weight loss results, however this has not yet been demonstrated in research studies.
Thyroid Hormone Levels and Weight Loss
It is well-documented that an increase in thyroid hormone levels can support an increased rate of fat burning in the body. Levels of T3 thyroid hormone directly regulate metabolism and energy utilization in the cells. This hormone stimulates the cell’s use of oxygen to oxidize or break down fat.
Research shows that when T3 is administered directly, it increases the metabolic rate of the body and promote weight loss in obese individuals. In one study on obese subjects on a calorie restricted diet, individuals given T3 lost an average of 92 grams of bodyweight per day.
It is unclear whether tyrosine is able to increase T3 thyroid hormone levels to any degree sufficient to promote weight loss. While there could potentially be a benefit for fat metabolism in individuals with low thyroid levels, there is no research which has looked at this possibility.
Safety of Using L-Tyrosine
L-tyrosine has been clinically tested at amounts up to 12,000 mg daily without causing any serious side effects. Common dosing suggestions range from 500 mg to 1500 mg daily for most therapeutic purposes.
If you have hypothyroidism, then there are also other natural approached you may want to consider for increasing thyroid functioning capacities. These include basing your diet on water-rich foods, discontinuing any usage of tobacco products, avoiding excessive iron intake, practicing yoga and engaging other methods to effectively manage your stress levels.
Speak with your doctor about supplementing L-tyrosine for weight loss.
- Qiu HM1, Yang JX, Jiang XH, Hu XY, Liu D, Zhou QX. Enhancing tyrosine hydroxylase and tryptophan hydroxylase expression and improving oxidative stress involved in the antidepressant effect of sodium valproate on rats undergoing chronic unpredicted stress. Neuroreport. 2015 Oct 28. [Epub ahead of print]
- Jongkees BJ1, Hommel B1, Kühn S2, Colzato LS3. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands-A review. J Psychiatr Res. 2015 Nov;70:50-7. doi: 10.1016/j.jpsychires.2015.08.014. Epub 2015 Aug 25.
- Ahmed RM1, Latheef S2, Bartley L2, Irish M2, Halliday GM2, Kiernan MC2, Hodges JR2, Piguet O1. Eating behavior in frontotemporal dementia: Peripheral hormones vs hypothalamic pathology. Neurology. 2015 Oct 13;85(15):1310-7. doi: 10.1212/WNL.0000000000002018. Epub 2015 Sep 16.
- Sarantis K1, Tsiamaki E1, Kouvaros S1, Papatheodoropoulos C1, Angelatou F1. Adenosine A2A receptors permit mGluR5-evoked tyrosine phosphorylation of NR2B (Tyr1472) in rat hippocampus: a possible key mechanism in NMDA receptor modulation. J Neurochem. 2015 Aug 25. doi: 10.1111/jnc.13291. [Epub ahead of print]
- Simone J1, Bogue EA2, Bhatti DL3, Day LE4, Farr NA5, Grossman AM6, Holmes PV7. Ethinyl estradiol and levonorgestrel alter cognition and anxiety in rats concurrent with a decrease in tyrosine hydroxylase expression in the locus coeruleus and brain-derived neurotrophic factor expression in the hippocampus. Psychoneuroendocrinology. 2015 Aug 28;62:265-278. doi: 10.1016/j.psyneuen.2015.08.015. [Epub ahead of print]
- Huang Q1, Zhou C1, Chen X2, Dong B1, Chen S1, Zhang N3, Liu Y4, Li A5, Yao M2, Miao J2, Li Q1, Wang Z1. Prodrug AST-003 Improves the Therapeutic Index of the Multi-Targeted Tyrosine Kinase Inhibitor Sunitinib. PLoS One. 2015 Oct 29;10(10):e0141395. doi: 10.1371/journal.pone.0141395.
Article last updated on: March 31st, 2018 by Nootriment