The Full Story on Tryptophan: Mood, Sleep, and Well-Being Explained

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Tryptophan plays a key role in producing serotonin, a mood-regulating neurotransmitter as well as melatonin for sleep. In this article, we’re going to delve into the science behind tryptophan’s effects, from improving your sleep quality to its role in emotional well-being.

And if Tryptophan supplements are right for you, this article will show you the best place to buy Tryptophan online. Supplement-Sciences has partnered with Fullscript’s professional-grade supplement formulary to provide a 20% discount on every order, so you always have access to the highest quality supplements.

What Is Tryptophan

L-Tryptophan (not to be confused L-Tryptopan) is an essential amino acid, which means that the human body cannot synthesize it and must obtain it from dietary sources. It plays a crucial role in the production of proteins and serves as a precursor for several important molecules, including serotonin, melatonin, and niacin (vitamin B3).

Serotonin is a neurotransmitter that contributes to feelings of well-being and happiness, while melatonin is a hormone that regulates sleep-wake cycles. As a dietary supplement, L-Tryptophan is often taken to promote relaxation, improve mood, and support sleep quality.

Natural sources of L-Tryptophan include various protein-rich foods such as poultry, eggs, dairy products, nuts, and seeds.

What are the Benefits of Supplements Tryptophan?

Tryptophan supplements have been found to be of benefit for many conditions related to brain function including:

  • Improves Sleep Quality: Tryptophan helps produce melatonin, a hormone that regulates sleep. Researchers found that 1 gram of tryptophan was more effective than lower doses. [PMC8181612, PMID: 33942088]
  • Mood Enhancement: It’s a precursor to serotonin, a neurotransmitter that helps regulate mood. A review of 11 controlled trials concluded that, “concluded that taking 0.14-3g of TRP per day in addition to the usual meal can be expected to improve the mood of healthy individuals.” [PMID: 32272859]
  • Stress Reduction: Increased serotonin levels can help reduce stress and anxiety. [PMID: 35343881]
  • Pain Tolerance: Some studies suggest that tryptophan can increase pain tolerance by affecting serotonin levels. [PMID: 6764935]
  • Appetite Regulation: Tryptophan can affect serotonin, which in turn can influence appetite and eating behavior. [PMC8038855]
  • Cognitive Function: Adequate tryptophan levels can support better cognitive performance, although more research is needed in this area. [PMID: 19715722]

Food Sources of Tryptophan

FoodTypical Serving SizeTryptophan (mg)
Turkey3.5 oz (100g)390
Chicken, Beef, Tuna3.5 oz (100g)300-350
Soybeans1 cup280
Pumpkin Seeds1 oz180
Cheese (Cheddar)1 oz70
Eggs1 large50
Milk1 cup45
Oats, Quinoa1 cup cooked35- 40
Corn, Rice (Brown)1 cup cooked15- 20
Wheat (Whole Grain)1 slice10
Note: The amounts listed are approximate and can vary based on factors like the specific variety of the food and growing

Tryptophan in Typical Diets

Diet TypeTypical Tryptophan Intake (mg/day)
Standard American Diet250-400

What’s The Difference Between Tryptophan and 5-HTP

Tryptophan and 5-HTP are both amino acids, but they serve different roles in the body. Tryptophan is an essential amino acid that you have to get from your diet. Once ingested, the body can convert tryptophan into 5-HTP. Then, 5-HTP gets converted into serotonin, a neurotransmitter that influences mood, sleep, and other functions.

Because 5-HTP is closer to serotonin in the metabolic pathway, it’s often more directly effective for increasing serotonin levels. On the other hand, tryptophan has more diverse roles, like building protein and other metabolic functions. So, while both can ultimately increase serotonin levels, 5-HTP is usually more effective for that specific purpose.

How Does Tryptophan Get Converted to Melatonin

Tryptophan serves as the starting point for the production of melatonin.

Tryptophan converts to 5-hydroxytryptophan (5-HTP), a closer precursor to serotonin.

Then, 5-HTP turns into serotonin, a neurotransmitter that plays a key role in regulating mood and sleep-wake cycles.

As night approaches and the environment gets dark, the body takes that serotonin and converts it into melatonin. This hormone is crucial for regulating sleep.

The entire process, from tryptophan to melatonin, involves multiple steps and different molecules, each with its own set of functions in the body.

Stress And Inflammation In The Breakdown of Tryptophan

When it comes to mental health, tryptophan’s role extends beyond just being a serotonin precursor. In conditions of stress or inflammation, the body prioritizes the kynurenine pathway over serotonin production. This effectively “steals” tryptophan from the serotonin pathway and can result in serotonin depletion, contributing to mood imbalances. One of the end products of this pathway is quinolinic acid, a neuroinflammatory substance. Higher levels of quinolinic acid have been linked to depression and anxiety.

Understanding the kynurenine pathway sheds light on how mood disorders may not solely be a result of serotonin imbalances, but also involve other metabolic routes. By providing the body with more tryptophan, you may not only bolster serotonin levels but also potentially influence the kynurenine pathway, offering a more holistic approach to mood regulation.

Even children and adolescents are susceptable to depression caused by psychosocial stress and inflammation leading to tryptophan depletion via the kynurenine pathway. [PMID: 29775873]

Are Tryptophan Supplements Safe?

Tryptophan supplements are generally considered safe for most people when taken within recommended dosage guidelines. Tryptophan has undergone various studies that affirm its safety profile. It’s available over the counter and commonly used for issues like insomnia or mood enhancement. While some people may experience minor side effects like nausea or headaches, these are often dosage-dependent and subside when usage is moderated. Just like its natural form in foods, tryptophan in supplement form is widely viewed as a safe option for boosting its presence in your body.

In 1989, tryptophan supplements were taken off the U.S. market after an outbreak of eosinophilia-myalgia syndrome (EMS), a serious condition affecting the muscles and blood. The issue was traced back to a contaminated batch of tryptophan produced by a single manufacturer in Japan. The contamination led to severe health problems for some people, including a few fatalities. As a result, the Food and Drug Administration (FDA) banned the sale of tryptophan supplements for several years. While tryptophan itself was not the cause of the health crisis, the incident raised concerns about the safety and quality control of dietary supplements. Tryptophan supplements have since returned to the market and are now subject to more stringent quality controls.

What Medications Interact with Tryptophan?

  • Antidepressants:
    • Antidepressants (SSRIs): Taking tryptophan with SSRIs like fluoxetine (Prozac) can increase serotonin levels, risking serotonin syndrome.
    • MAO Inhibitors: Combining tryptophan with MAOIs like phenelzine (Nardil) can also raise serotonin levels to risky amounts.
    • Tricyclic Antidepressants: Combining tryptophan with medications like amitriptyline can increase the risk of side effects.
  • Sedatives: Medications like lorazepam (Ativan) or diazepam (Valium) can have enhanced sedative effects when taken with tryptophan.
  • Anti-migraine Medications: Drugs like sumatriptan (Imitrex) may interact with tryptophan, potentially increasing serotonin levels.
  • Pain Relievers: Some over-the-counter pain medications like aspirin can interact with tryptophan, affecting how it’s metabolized.

What Supplement Interact with Tryptophan?

  • St. John’s Wort: This herbal remedy for depression can also increase serotonin levels, so combining it with tryptophan could risk serotonin syndrome.
  • 5-HTP: Another precursor to serotonin, taking 5-HTP with tryptophan can cause an excess of serotonin, again posing a risk for serotonin syndrome.
  • SAMe (S-Adenosylmethionine): Often used for mood elevation, SAMe can also interact with tryptophan to elevate serotonin levels, leading to the same risks.
  • Melatonin: Both are used for sleep support, but combining them may result in excessive drowsiness.
  • Ginseng: This root is often used for boosting energy, but combining it with tryptophan may reduce the effectiveness of tryptophan’s calming effects.

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L-Tryptophan 500mg by Protocol for Life Balance

  • Supports Relaxation*
  • Encourages Positive Mood*
  • Promotes Restful Sleep*

L-Tryptophan is an essential amino acid; therefore, it is not synthesized by the body and must be obtained from the diet. In the brain, Tryptophan is converted into serotonin, a neurotransmitter involved in feelings of well-being, calmness, personal security, and relaxation.* It also plays a role in the regulation of appetite and synchronization of sleep patterns.* Every lot of Protocol For Life Balance® L-Tryptophan is tested to be free of Peak E and microbial contamination.

 Suggested Use:Take 1-2 capsules twice daily on an empty stomach, with final dose at bedtime, or as directed by your healthcare practitioner

Amount Per 2 Capsule Serving
L-Tryptophan … 1g (Free-Form)(2-amino-3-indolylpropanoic acid)

To Sum It Up

Tryptophan supplements offer various health benefits, from enhancing mood to improving sleep quality. They serve as a building block for important molecules like serotonin and melatonin, affecting your emotional well-being and sleep patterns. Some people also find them helpful for reducing anxiety and managing stress. While the supplements have a good safety profile, it’s always wise to know how they interact with other medications or supplements you may be taking. With their multi-faceted benefits, tryptophan supplements are an option worth exploring for better mental and physical health.

This Article is Not a Substitute for Medical Advice

Dietary supplements are not designed to diagnose, treat, cure, or prevent any disease. The Supplement Sciences website seeks to provide comprehensive access to the most relevant supplement information along with convenient online ordering. We do not provide medical advice and cannot guarantee that every product suggested is completely without risk. Since each person is unique in their health history and medication use, it is important to discuss supplements with your personal physician. Specifically, pregnant women and individuals being treated for cancer or liver or kidney problems must consult their physician about every nutritional supplement they plan to take. People taking medications for the treatment of HIV or with a history of organ transplant must not take supplements without consulting with their physician.

About the Author

Stephanie Figon, MS, RDN, LD

Creator of Supplement Sciences and NutriScape.NET. As a dietitian since 1992, Steph has had experiences in consulting, 15 years in clinical, and has operated a private practice nutrition counseling office for since 2011. Log in to comment and save this article on your board or send your comments to

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