L-Tryptophan is a serotonergic amino acid that enhances your mental wellbeing, and helps you get out of the stress-sleep cycle that prevents you from achieving deep sleep.

While the myth that turkey gets you to sleep because it has L-Tryptophan is just a myth. It’s true that L-Tryptophan itself may enhance our sleep quality.

As an essential amino acid that plays a part in the serotonergic brain pathways, L-Tryptophan is suggested to enhance our mood and sleep by converting to (1):

  • Melatonin in our gut while also supporting the natural melatonin production in our pineal gland.
  • 5-HTP, a building block of serotonin, which is best known for supporting healthy mood, rest, and relaxation.

By supporting the creation and effectiveness of mood- and sleep-influencing brain chemicals, L-tryptophan helps you have sounder sleep at night and more energy in the morning.

L-Tryptophan as a Nootropic – The Overview

L-Tryptophan or simply Tryptophan is an amino acid that you get from foods like cheese, eggs and bananas. It’s a precursor to serotonin, vitamin B3, and melatonin, which means your body needs Tryptophan to make these compounds.

The conversion of Tryptophan into 5-HTP (which later turns to serotonin in your brain) is facilitated by an enzyme called Tryptophan hydroxylase. We know, it’s a mouthful!

Related: Does Honey Help You Sleep?

For your body to make ‘the happy chemical’ serotonin, you need to give it the raw building blocks in the form of Tryptophan. As a nootropic, Tryptophan is used for ADHD, depression, pain, memory decline, anxiety, and most often – insomnia.

A deficiency in Tryptophan in your body can have a massive impact on your life. This amino acid helps with:

  • Focus and Concentration – Low serotonin and tryptophan levels in the brain are linked with inability to focus and stay still. Some studies show that ADHD children have about 50% lower levels of Tryptophan than average.
  • Mood & Anxiety – As it’s needed to make serotonin, Tryptophan plays a crucial role in our mood, learning, sleep, and even metabolism & food cravings.
  • Brain chemicals – Chronically low Tryptophan levels can lead to memory loss. Tryptophan supplementation has, in some cases, been shown to help improve memory in normal adults.

Does Tryptophan Raise Your Serotonin Levels?

While eating Tryptophan-rich foods will raise your body’s levels of this amino acid. It won’t necessarily raise your brain’s serotonin levels. And here’s why…

Out of 8 essential amino acids, Tryptophan has the lowest concentration in your body. Tryptophan competes with other amino acids for the same receptors in your brain and body.

However, studies show that when you add carbohydrates in your meals, the insulin helps your body utilize more of Tryptophan by removing some of the other amino acids from the competition. And if your diet has a higher amount of protein, it can slow down the increase of serotonin in your brain. (2)

Related: L-Theanine Nootropic Review

How Does L-Tryptophan Work

As we’ve seen, Tryptophan first turns into 5-HTP, which then converts into serotonin: the neurotransmitter that induces feelings of happiness. During the day, your serotonin is the highest, but during the night, it turns into melatonin – the sleep hormone.

Apart from enhancing your sleep, Tryptophan works in the brain in two main ways:

  1. Boosts memory – As a nootropic, L-Tryptophan is best known to support certain areas of mental function, one of which is memory. It also boosts neurotransmitters such as endorphins. (3)
  2. Supports mood – Being the master precursor to 5-HTP and serotonin, Tryptophan can have a massive impact on your mental well-being, depending on how deficient you are in it. Not only that, but supplementing Tryptophan has also been seen to raise prolactin and growth hormone. (4)

Who is L-Tryptophan For?

Is L-Tryptophan for you? Should you supplement it?

Tryptophan is for anyone who’s anxious, irritable, and stressed out from their everyday life. Our modern lifestyles have left many people struggling with sleep, aggressive behavior, pain, lack of motivation, and even depression. All of these have been linked to not having enough serotonin in your brain. (4)

More and more researchers recognize the role of serotonin in behavior problems and its link to Tryptophan deficiency. (5)

As you saw above, Tryptophan hydroxylase is the enzyme that your brain uses to make serotonin. However, this enzyme can be blocked by nutrient deficiencies, insulin resistance, aging, and too much stress.

How Tryptophan Can Help You

Some people take Tryptophan with the goal to help with their sleep, or simply as a natural alternative to pharmaceuticals.

Dosing L-Tryptophan before bed at night can help you feel better the next day. You should have more mental and physical energy.

Mood should improve, and stress levels decrease. You might notice that your self esteem has improved after taking the amino acid. Apart from that, tryptophan also helps with memory.

Related: 5 Best Herbs for Neurogenesis

Key Tryptophan Benefits

1. Benefits Mood Swings

A study from Washington University looked into the link between depression and serotonin. The study results showed that low serotonin levels could be a major contributor to poor well-being and mood issues.

Similar to how SSRIs work, Tryptophan may help support brain serotonin levels. Too little serotonin in the brain leads to impaired transmission of signals between your nerve cells. SSRIs work to increase the levels of serotonin, not directly, but by blocking its breakdown.

Unfortunately, you can’t raise serotonin by simply taking it, it can only be synthesized from compounds such as L-Tryptophan. That’s why you should ensure to get enough of this amino acid daily.

The serotonin precursor also modulates other processes in your body, including bowel function, immunity, and inflammation.

2. Boosts Memory Performance

As I’ve repeated, low tryptophan levels correlate with short- and long-term memory decline. Not only that, but a deficiency in the amino acid can also impair overall cognitive function due to the role it plays in serotonin synthesis. A study done at the University of Bordeaux showed that tryptophan is capable of improving memory in both healthy adults, and those who have memory lapses.

3. Helps You Sleep

Just as essential is L-Tryptophan for the making of melatonin as it is for the making of serotonin. If you have too little of L-Tryptophan, it can lead to an inability to fall asleep. Increasing the levels of this nutrient in the body can help you get to sleep faster, sleep better, and wake up more energized the next day.

The Research

Study #1: Tryptophan and Mood

In a double-blind crossover study, 20 patients who suffered from depression were examined. The researchers depleted their tryptophan levels through diet, so that they could see the effects on their mood and cognitive function.

The study found what many have suggested before – lower Tryptophan levels lead to mood issues, poor attention, and hard time processing new information. (6)

Study #2: Tryptophan to Boost Physical Performance

Have you ever had to cut a workout short even though you weren’t physically tired? Some experts suggest it could be due to low Tryptophan in the body. And how it affects serotonin in your brain.

In one study, 20 healthy young males trained at about 50% of their capacity followed by maximum physical exertion for an additional 30 minutes. This was repeated 3 times, and after the 4th time, each study participant finished the workout with 20 minutes of maximum intensity.

They performed this protocol twice: once with Tryptophan and once without it. When they took Tryptophan, their power output during the final 20 minutes was higher than when they took a placebo. (7)

In another study from Spain, 12 healthy athletes were asked to run on a treadmill until exhaustion. As with the previous study, they repeated the workout two times: once when taking Tryptophan and once with a placebo. The researchers measured several parameters during both tests:

  • Total exercise time
  • Maximum heart rate
  • Pulse recovery rate
  • Oxygen consumption

The most stunning finding was that Tryptophan increased their total exercise time by 50% compared to placebo. Additionally, their perception of exertion was lower when taking the amino acid. (8) Some researchers suggest that this could be due to the increased pain tolerance from taking L-Tryptophan.

Related: What are the Benefits of Phosphatidylserine?

What Does Tryptophan Feel Like?

Taking L-Tryptophan should help you relax and unwind when you take it before bed. It also helps you feel great the next day. You should notice an increase in energy and motivation to pursue your goals.

Anxiety should reduce and overall happiness increase. Tryptophan could also help you with memory and overall cognition – you might notice that you’re able to recall information more easily.

In rare cases where people get optimal amounts of L-Tryptophan every day, they might not feel anything from supplementing it.

How to Get the Most Out of L-Tryptophan

You can get L-Tryptophan as a powder or in capsule and tablet forms. The dosage per serving usually ranges between 500-1000mg. You also get some tryptophan from foods including dried dates, cottage cheese, meat, fish, oats, bananas, and chocolate.

One of the most effective forms of L-Tryptophan is Tryptopure® which is manufactured in Japan. You’ll find it in higher quality supplements like Performance Lab Sleep. Containing NutriGenesis® magnesium, melatonin derived from tart cherries, and premium Tryptophan, Performance Lab Sleep is currently our favorite product for nighttime regeneration support and daytime performance enhancement.

Learn more about Performance Lab Sleep by clicking here.


For cognitive benefits, the recommended Tryptophan dosage is 500-1000mg per day. However, it’s always important to talk with your doctor before thinking about starting any new supplement, especially if you have a medical condition. If you do choose to supplement Tryptophan, start with the lowest recommended dosage to asses your tolerance.

Side Effects

Generally, Tryptophan is considered as safe as it’s a normal part of our diets. Even when supplemented it’s shown to be non-toxic as long as you stick to the recommended doses. In a rare case where the body has more than enough tryptophan, supplementing with it can cause discomfort.

Never take Tryptophan with an antidepressant. Please consult with a healthcare professional if you have any medical questions. This article is not medical advice!

Anything Else to Consider?

Your body gets some L-Tryptophan from your diet. However, this amino acid competes for transport with other nutrients, which can over time deplete your Tryptophan stores. Supplementing with L-Tryptophan will ensure you have enough of it available for the production of serotonin and melatonin.

If you want to improve your sleep, make sure to take the highest quality L-Tryptophan available, and as a part of a professional supplement stack – click on the picture below to see our #1 rated product.


Does Tryptophan Make You Tired?

Yes, Tryptophan can make you feel a bit tired. This is due to how it works in your brain – helping with the synthesis of melatonin, the sleep hormone. That’s why many people like to take it before sleep.

Does Tryptophan Cause Weight Gain?

Tryptophan shouldn’t cause weight gain, if anything, it should help you maintain a healthy body fat percentage. This is because tryptophan is essential for the formation of serotonin which regulates your appetite control.

How Long Does it Take for Tryptophan to Start Working?

Tryptophan should start working within 30-60 minutes after ingestion. The amount of time it takes for it to start working depends on if you took it with food or an empty stomach.

Can I Take Melatonin and Tryptophan Together?

You should always ask your doctor about any questions you might have regarding supplementation. However, currently there’s no reputable evidence showing that melatonin and tryptophan can’t be taken together – in fact, some of the best sleep supplement formulas use them in conjunction for improved sleep.


Stress and mood swings impair our sleep. The impaired sleep then leads to daytime grogginess, irritability and poor focus.

L-Tryptophan is an essential amino acid that helps break this unhealthy cycle, enhancing your brain’s levels of serotonin and melatonin – two neurotransmitters that are critical for healthy mood and sleep patterns.

Our favorite form of L-Tryptophan is TryptoPure, which is produced in Japan. Whether you take it as a standalone ingredient or as a part of a high-quality formula such as Performance Lab Sleep, it’s a great way to enhance nighttime recovery and optimize daytime performance.

  1. Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis. (source)
  2. The composition of lunch determines afternoon plasma tryptophan ratios in humans. (source)
  3. Relationship of brain tryptophan and serotonin in improving cognitive performance in rats. (source)
  4. Hormonal and behavioral effects associated with intravenous L-tryptophan administration. (source)
  5. L-tryptophan in neuropsychiatric disorders: a review. (source)
  6. Tryptophan depletion and its implications for psychiatry. (source)
  7. The effects of high-dose and low-dose tryptophan depletion on mood and cognitive functions of remitted depressed patients. (source)
  8. L-tryptophan supplementation can decrease fatigue perception during an aerobic exercise with supramaximal intercalated anaerobic bouts in young healthy men. (source)
  9. Effect of L-tryptophan supplementation on exercise performance. (source)
About Valentino M. 110 Articles
Valentino is a qualified nutritionist, nootropic reviewer, and meditation coach. He draws upon years of research, testing, and personal experience within the holistic lifestyle - to deliver information based on the latest studies to unclutter the confusing world of nutrition. More...

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