Getting enough sleep every night is kind of a big deal.

Lack of sleep is shown to cause numerous health conditions, including heart disease, cognitive impairments, and low testosterone in men. (2)

In fact, just one week of sleep restriction leads to plummeting T levels in young males. (1)

In order to improve their sleep duration, as well as quality, people look for various solutions. Some opt for medications, while others choose natural supplements, such as l-tryptophan.

We won’t talk about medications here since they’ve been shown to actually sedate you, instead of making you fall asleep. And there’s a big difference between the two. Studies show that sedation kills deep (REM) sleep. (3)

Instead, we’ve chosen a natural, and more effective route, which is consuming l-tryptophan.

This article explains why does l-tryptophan help you sleep.

Let’s start off by explaining what tryptophan is and how it works.

What is L-Tryptophan

L-tryptophan is an amino acid. Amino acids are building blocks of protein.

L-tryptophan naturally occurs in many foods, particularly those that contain proteins.

Besides making proteins, amino acids such as tryptophan have other important roles in the body.

One of these roles is to make the neurotransmitter serotonin.

Found in the brain and the gut, serotonin is a chemical messenger that regulates sleep, mood, and appetite.

Serotonin is also a precursor to melatonin, which is the hormone that helps you fall asleep. Do you see where this goes?

How Does it Work?

Okay, you might be wondering how does l-tryptophan convert to melatonin, the sleep hormone?

To start the process, your body converts tryptophan into 5-HTP. This is a molecule which is directly used by the body to create serotonin.

Once 5-HTP converts to serotonin, there’s just one step of conversion left, which is serotonin turning to melatonin.

You may be asking, how does your body know when it’s time to convert serotonin to melatonin?

It’s simple. When the sun is out, your body produces serotonin. When it gets dark, serotonin converts to melatonin – this is how your body tells you it’s time to sleep.

Why L-Tryptophan Does Make You Sleep?

Now that you know how l tryptophan works, it’s easy to see why it makes you sleep.

When you eat food rich in l-tryptophan or take a tryptophan supplement, your levels of serotonin and melatonin raise.

In other words, increased levels of l-tryptophan lead to higher levels of the sleeping hormone. Making you want to hit the sack. (4, 5)

teddy bear by a laptop at night

Can Low L-Tryptophan Levels Cause Insomnia?

Since l-tryptophan is a building block for 5-HTP, and consequently serotonin and melatonin, low levels of this amino acid could give you insomnia.

But that isn’t the only problem with low tryptophan.

Other Side Effects of Low L-Tryptophan

Anxiety and Depression

A number of studies showed that people with depression usually have low tryptophan levels. (6, 7)

To further prove this, experts deliberately altered tryptophan blood levels in volunteers by changing the amino acid contents of their food.

After this, the researchers exposed these volunteers to a stressful event twice. One time, when they had normal tryptophan levels. And later, when their blood tryptophan levels were low.

The study found that volunteers had much higher anxiety and nervousness when their tryptophan levels were low. (8, 9)

Looking at these results, it’s clear that low tryptophan can cause more than just a poor night of sleep. It can also negatively affect your day to day life.

On the other hand, studies show that supplementing with tryptophan reduces anxiety and improves socialization between people. (10)