Does L-Tyrosine Increase Dopamine?

Updated on February 26, 2024
 by — reviewed by Jason Williams, PhD (Contributor: George Collins / Editor: Yoko Hill)
Exploring the biochemical link between L-Tyrosine and dopamine synthesis in the human brain.

Does L-Tyrosine really increase dopamine?

Dopamine, often referred to as the “feel-good” neurotransmitter, plays a crucial role in our mood, motivation, and overall sense of well-being. Many people are curious about whether l-tyrosine, an amino acid, and precursor to dopamine, could potentially increase dopamine production in the brain.

In this article, we will explore the scientific evidence behind this claim and uncover the truth about l-tyrosine’s effects on dopamine levels.

Understanding these mechanisms of action will empower you to make informed choices in your wellness journey and help you to improve your cognitive health.

Understanding L-Tyrosine and Its Role in the Body

L-tyrosine, also known as tyrosine, is an essential amino acid that is used by cells to synthesize proteins. It plays a crucial role in protein synthesis and is involved in the production of neurotransmitters in the brain.

One of the main functions of L-tyrosine is its role in the production of neurotransmitters such as epinephrine, norepinephrine, and dopamine.

These neurotransmitters help nerve cells communicate and influence mood. L-tyrosine also helps produce melanin, the pigment responsible for hair and skin color.

Moreover, L-tyrosine is involved in the function of organs responsible for making and regulating hormones, including the adrenal, thyroid, and pituitary glands. It is also involved in the structure of almost every protein in the body.

While it is rare to be deficient in L-tyrosine, low levels have been associated with low blood pressure, low body temperature, and an underactive thyroid. 

L-tyrosine is also important for individuals with phenylketonuria (PKU), a condition where the body cannot use the amino acid phenylalanine. People with PKU must avoid phenylalanine in their diets, which can lead to a deficiency in L-tyrosine.

In such cases, L-tyrosine is used in protein supplements for people with PKU.

Does L-Tyrosine Raise Dopamine Levels?

Yes, L-tyrosine can increase dopamine levels. It is a precursor to neurotransmitters, including dopamine, which suggests that its supplementation can potentially enhance dopamine production.

This, in turn, may improve cognitive performance, as demonstrated in several studies involving healthy young participants.(1)

The Connection Between L-Tyrosine and Dopamine

Dopamine, oftentimes referred to as the “feel-good” hormone, plays a crucial role in various physiological functions, including mood regulation, motor control, and reward-motivated behavior.

One essential component in the production of dopamine is L-tyrosine – Let’s highlight the role of enzymes involved in this intriguing process:

  1. Conversion of L-Tyrosine to L-DOPA: The initial step in dopamine synthesis involves the conversion of L-Tyrosine to L-DOPA (dihydroxyphenylalanine). This process is catalyzed by an enzyme called Tyrosine hydroxylase (TH). TH uses tetrahydropteridine as a cofactor to convert L-Tyrosine into L-DOPA.
  2. Alternative Enzyme: In addition to Tyrosine hydroxylase, another enzyme called Tyrosinase (oculocutaneous albinism IA) can also convert L-Tyrosine to L-DOPA. However, this enzyme is primarily associated with a medical condition called oculocutaneous albinism IA.
  3. Conversion of L-DOPA to Dopamine: Once L-DOPA is formed, it undergoes further transformation into dopamine. This conversion is mediated by the enzyme Dopa decarboxylase (aromatic L-amino acid decarboxylase), also known as AADC. Dopa decarboxylase removes a carboxyl group from L-DOPA, resulting in the formation of dopamine.
  4. Major Metabolites of Dopamine: Dopamine can be further metabolized into various compounds, such as dihydroxyphenylacetic acid, 3-methoxytyramine, and norepinephrine. However, in invertebrates, these metabolites are found at low levels, as the enzymes involved in their catabolism have not been identified yet.
  5. Dopamine Signaling in Invertebrates: Studies conducted on invertebrate models, such as the nematode, have been instrumental in understanding the molecules involved in dopamine synthesis, packaging, reuptake, and signaling. In these models, dopamine arises from a small number of cells that regulate a larger network governing various physiological functions.
  6. Key Enzymes and Receptors: In invertebrates, the synthesis and regulation of dopamine involve critical enzymes and receptors that are similar to those found in mammals. For instance, the Cat-1 protein acts similarly to mammalian vesicular monoamine transporters (VMATs) by packaging dopamine into synaptic vesicles. Mutations in Cat-1 result in reduced dopamine levels.
  7. Dopamine Receptor Subtypes: In invertebrates, dopamine functions through four receptor subtypes, Dop-1 through Dop-4. These receptors have different pharmacological properties compared to their mammalian counterparts. Dop-1 and Dop-4 exhibit similarities to mammalian D1 dopamine receptors, while Dop-2 and Dop-3 resemble D2 class receptors.
  8. Functional Roles of Dopamine: Dopamine-mediated functions in invertebrates include egg-laying behaviors, defecation, basal motor activity, sensation/response to food sources, and habituation to touch. Each receptor subtype has been associated with specific roles, such as Dop-1 being important for the maintenance of the avoidance response and Dop-3 being implicated in dopamine-induced paralysis and basal slowing mechanisms.

In conclusion, L-tyrosine serves as a precursor for dopamine synthesis, playing a vital role in the production of this essential neurotransmitter.

Understanding the biochemical pathway and the enzymes involved in converting L-Tyrosine to dopamine sheds light on the intricate mechanisms underlying dopamine signaling and its impact on various physiological processes.

The Impact of L-Tyrosine Supplementation on Dopamine Levels

You can find L-tyrosine naturally in foods like soy products, chicken, avocados, bananas, milk, cheese, and sesame seeds.

However, the best way to ensure you have balanced levels of this essential amino acid is by adding dose-regulated L-tyrosine supplements.

Supplementation of L-tyrosine has the following key benefits:

  • Improved Mental Alertness: L-tyrosine is an amino acid that is involved in the production of chemical messengers in the brain, such as dopamine. These messengers are responsible for mental alertness, which can help improve focus, concentration, and cognitive performance.(2)
  • Increased Motivation and Drive: Adequate dopamine levels are associated with heightened motivation, allowing individuals to pursue goals with more enthusiasm.
  • Enhanced Focus and Cognitive Performance: Optimal dopamine levels contribute to improved concentration, mental clarity, and memory retrieval abilities.
  • Support for Addiction Recovery: Dopamine dysregulation is often associated with addiction. L-tyrosine supplementation may help restore dopamine balance and support individuals in their recovery process.
  • Stress Relief: L-tyrosine has been shown to help alleviate stress.(3) During times of stress, the body’s levels of neurotransmitters can become depleted. L-Tyrosine helps replenish these neurotransmitters, which can help reduce feelings of stress and improve mood.
  • Depression Management: Research has shown that L-tyrosine may play a role in managing depression. It is believed that an imbalance of neurotransmitters in the brain can contribute to depression, and L-tyrosine can help increase the levels of these neurotransmitters, leading to improved mood.
  • Enhanced Memory Under Stressful Conditions: L-tyrosine has been found to improve memory and cognitive function during stressful situations. When the body is under stress, cognitive performance may decline, but L-tyrosine can help mitigate these effects and improve memory and cognitive flexibility.
  • Potential Treatment for Phenylketonuria (PKU): Phenylketonuria is a rare genetic disorder that affects the body’s ability to process phenylalanine, an amino acid that is used to make L-Tyrosine. L-tyrosine supplements may help manage the symptoms of PKU by providing the necessary tyrosine without the excess phenylalanine.

While further research is necessary to fully understand the long-term effects, existing studies highlight the importance of neurotransmitter balance in promoting brain health.

Potential Side Effects of L-Tyrosine Supplementation

L-tyrosine supplements are regarded as safe, but like any other supplement, they may cause side effects in some individuals.

Here are some common side effects and precautions associated with L-tyrosine supplementation:

  1. Gastrointestinal Upset: Some individuals may experience gastrointestinal issues such as nausea, stomach pain, or diarrhea when taking L-Tyrosine supplements. If you have a sensitive stomach or a history of digestive problems, it’s recommended to start with a lower dosage and gradually increase it to assess your tolerance.
  2. Headache: L-Tyrosine can potentially cause headaches in certain individuals. If you experience frequent headaches after starting L-Tyrosine supplementation, consult with a healthcare provider to determine the cause and adjust the dosage if necessary.
  3. Interactions with Medications: L-Tyrosine supplements may interact with certain medications, such as MAOIs (monoamine oxidase inhibitors) used to treat depression, levodopa used for Parkinson’s disease, and thyroid hormone medications. These interactions can have adverse effects on your health. Always consult with your healthcare provider before taking L-Tyrosine if you are on any medication.


  1. Pregnancy and Breastfeeding: There is limited information on the safety of L-tyrosine supplementation during pregnancy and breastfeeding. It’s recommended to stick to dietary amounts of L-Tyrosine and avoid supplementation unless advised by a healthcare provider.
  2. Thyroid Disorders: L-tyrosine is involved in the production of thyroid hormones. If you have a thyroid disorder, such as hyperthyroidism or Graves’ disease, taking L-tyrosine supplements may increase thyroid hormone levels and worsen your condition.
  3. Migraine Headaches: Individuals who suffer from migraine headaches should avoid L-tyrosine supplements as they can potentially trigger migraines and worsen symptoms.
  4. Quality of Supplements: Ensure that you are using high-quality L-tyrosine supplements from reputable manufacturers to minimize the risk of contamination or other issues.

Conclusion: Does L-Tyrosine Increase Focus

Incorporating L-Tyrosine into your routine through supplementation can be a great way to promote relaxation, improve your mood, reduce anxiety, and improve cognition. The unique ability of this amino acid to boost levels of neurotransmitters like X makes it a go-to supplement for those looking for a way to promote optimal brain health.

If you’re interested in exploring L-Tyrosine further, be sure to consult with a healthcare professional to determine the best dosage and form for you.

Remember, it’s always important to prioritize your health and well-being.

Sources, Studies, and Scientific Research
  1. Kühn, Simone et al. “Food for thought: association between dietary tyrosine and cognitive performance in younger and older adults.” Psychological research vol. 83,6 (2019): 1097-1106. doi:10.1007/s00426-017-0957-4 ↩
  2. Hase, Adrian et al. “Behavioral and cognitive effects of tyrosine intake in healthy human adults.” Pharmacology, biochemistry, and behavior vol. 133 (2015): 1-6. doi:10.1016/j.pbb.2015.03.008Z ↩
  3. Banderet, L E, and H R Lieberman. “Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans.” Brain research bulletin vol. 22,4 (1989): 759-62. doi:10.1016/0361-9230(89)90096-8 ↩