We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is Tryptophan?

Tricia Christensen
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Tryptophan is an amino acid, a protein without which humans could not survive. It comprises one of the building blocks of DNA and is vital to the production of serotonin and melatonin. It is also widely accessible in dairy foods, bananas, chocolate and poultry.

Certain old-fashioned cures for sleeplessness were based on the consumption of foods with tryptophan. For example, drinking a glass of milk before bed was said to aid in sleeping. Though people were unaware at the time that this amino acid existed, it is clear that such early prescriptions for increasing sleepiness were at least mildly effective. Today, one may hear similar prescriptions for including tryptophan foods in the diet not only to promote sleep but also to improve mood.

Since serotonin is produced through the action of tryptophan, low levels of it in the body may result in depression or anxiety. Most drugs that treat anxiety and depression do not, however, supplement this amino acid, but inhibit serotonin from being too quickly absorbed by the brain. The increased level of free serotonin is thought to decrease anxiety and depression, and is frequently effective. Though unproven, those who suffer from anxiety or depression might also be able to increase their serotonin levels by adding tryptophan-rich foods to their diet. Including dairy products, which are also thought to help trim waistlines, may make antidepressants more effective.

In the US in the late 1980s, tryptophan supplements were linked to an outbreak of a serious bacterial autoimmune disorder, eosinophilia-myalgia syndrome. This disease was deadly, and as a result, the supplements were pulled from the US market.

Further studies revealed that the bacteria used to culture manufactured tryptophan were causing the disease, and that the specific bacteria were only being used by a Japanese manufacturer who had provided about 70% of supplements in the US. This disease did not occur with supplements grown from other bacteria, and therefore its occurrence was mostly connected with those who obtained their supplements in the US. No cases were reported in Britain and most of Europe, where it remained widely available. In 2001, the US Food and Drug Administration allowed tryptophan back on the market.

While maintaining a normal level of tryptophan is important, abnormally high levels have been linked to delusional thinking, paranoid and obsessive behavior, and other markers of schizophrenia. Some medical theorists believe that schizophrenia may be caused by the body's inability to recognize and use tryptophan properly. The result is a toxic waste product that creates psychotic symptoms.

As with any other nutritional supplement, it is advisable to seek medical advice before taking tryptophan, as it may interact with other medications or cause adverse effects. A psychiatrist may also prescribe it for those who are not benefiting from other antidepressants, or to enhance their effectiveness.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Tricia Christensen
By Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia Christensen is based in Northern California and brings a wealth of knowledge and passion to her writing. Her wide-ranging interests include reading, writing, medicine, art, film, history, politics, ethics, and religion, all of which she incorporates into her informative articles. Tricia is currently working on her first novel.
Discussion Comments
By anon985156 — On Jan 14, 2015

So now we know why, with the turkey feast and all, that the pilgrims and indigenous people got along so well because of all the tryptophan serotonin precursor in the meal. Amazing factoid finally explained!

By BioNerd — On Dec 08, 2010


This is an important point, and can sometimes go unheeded by the casual buyer and user of non-prescription dietary supplements. For mental health, it is almost always helpful to consult a psychiatrist and have the right medication or dietary supplement recommended or prescribed for you. These professionals are trained in the functions of various body chemicals and the ways in which certain medicines can aid you in maintaining a stable level of such chemicals. To buy pills on a whim, or based on an advertisement, is seldom if ever a good idea.

By hangugeo112 — On Dec 06, 2010

I am often confused by the names and functions of various body chemicals. Sometimes they are said to be good cures for mania or depression, and other times they are said to be the causes of abnormal brain functions. I often wonder how I'm supposed to tell if a certain dietary supplement is going to help me or harm me.

By catapult43 — On Dec 19, 2008

Fish like salmon, tuna and halibut, vegetable such as spinach and mustard greens, chicken and of course turkey are all very good sources of tryptophan.

Tricia Christensen
Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia...
Learn more
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.