Tyrosine

Our rating
 No smiley: On the available evidence, this treatment does not seem to be effective.

What does this rating mean?

The rating system

  • 3 smiliesThese treatments are very useful. They are strongly supported as effective by scientific evidence.
  • 2 smiliesThese treatments are useful. They are supported by scientific evidence as effective, but the evidence is not as strong.
  • 1 smileyThese treatments are promising and may be useful. They have some evidence to support them, but more evidence is needed to be sure they work.
  • No smiley On the available evidence, these treatments do not seem to be effective.
  • Question markThese treatments have not been properly researched. It is not possible to say whether they are useful or not.
  • These treatments are not recommended and could be dangerousSafety or other concerns have been raised for the use of these treatments.

What is it?

Tyrosine is an amino acid, one of the building blocks of protein. Tyrosine is found in protein-rich foods like meat, fish, eggs, dairy products and beans.

How does it work?

Tyrosine is used by the body to make the neurotransmitter (chemical messenger) noradrenaline. Noradrenaline is believed to be in short supply in the brains of people who are depressed.

Is it effective?

There is only one good scientific study on tyrosine as a treatment for depression. Participants in this study were 65 adults with clinicla depression. They were treated with either tyrosine supplements, an antidepressant medication (imipramine) or a placebo (dummy pill). Tyrosine was no more effective than the placebo at reducing depression.

Are there any disadvantages?

While tyrosine seems to be well tolerated, tyrosine supplements could cause side effects in some people. Like all supplements, it’s best to talk to your doctor or pharmacist if you are thinking of taking tyrosine to see if it could interfere with any other medication you are taking.

Where do you get it?

Tyrosine is available as a dietary supplement from health food shops.

Recommendation

On the limited evidence available, tyrosine is not an effective treatment for depression.

Key references

  • Gelenberg AJ, Wojcik JD, Falk WE, et al. Tyrosine for depression: a double-blind trial. Journal of Affective Disorders 1990; 19: 125-132.

Last reviewed and updated: 1 November 2019