What to know about L-tryptophan supplements

What to know about L-tryptophan supplements

L-tryptophan is an essential amino acid that performs many of the body’s functions, including serotonin production. In the brain, serotonin is a chemical that influences mood.

While some evidence indicates that L-tryptophan can help with some conditions , such as anxiety or sleep disorders, more research is required to show whether it is beneficial to take L-tryptophan supplements or not.

The safety and efficacy of L-tryptophan supplements are discussed in this article.

What is L-tryptophan?

L-tryptophan supplement

An essential amino acid that plays a role in the development of serotonin is L-tryptophan, or tryptophan. The hormone serotonin is found in different parts of the body, including the brain. The brain’s serotonin helps control the mood , anxiety, and happiness levels of a person.

L-tryptophan is also available as a supplement.

Potential benefits

Since L-tryptophan plays a role in the development of serotonin in the brain, it can aid with conditions such as anxiety and sleep disorders, some experts believe. To support its use for these purposes, there is some evidence.


The researchers found in one small study of 25 young adults that adjusting the participants’ diets to include more L-tryptophan created positive changes in their mood. It also decreased depression or anxiety.

The researchers found in a 2016 analysis that there may be a correlation between low levels of L-tryptophan and symptoms of depression and anxiety in rodents.

In humans, the authors noted that individuals with risk factors for developing depression are the most likely affected ones. It is possible that populations at risk can benefit from increased levels of tryptophan.


The researchers found that the participants saw little or no changes in psychiatric symptoms associated with their detox process in a 2016 study of young people undergoing opioid detox.

They noticed, however, that during the detox phase, L-tryptophan was successful in helping the participants sleep. The researchers also noted that there is a need for further studies to prove how effective it can actually be.

Premenstrual dysphoric disorder

L-tryptophan may aid in alleviating pain associated with premenstrual dysphoric disorder, according to an older study. The study also showed that there were worse premenstrual syndrome (PMS) symptoms for people who had small quantities or none of the amino acids in their diets.

Pain tolerance

The researchers investigated how L-tryptophan levels influence the tolerance of a person to pain in a 2017 study. The study showed that pain was made more manageable by higher levels of this amino acid.

Side effects

when a person consumes it as part of their periodic diet, L-tryptophan is healthy. An individual can encounter minor side effects when consuming it in supplement form.

Some common but mild side effects, according to one study, include:

  • nausea
  • tremor
  • sleepiness (in those not taking it for sleep disorders)
  • dizziness

Risks, risks
Although this is not common, if they take several drugs for depression or anxiety at the same time , a person can experience serotonin syndrome.

Though uncommon, when a person takes an L-tryptophan supplement with drugs that modify serotonin levels, such as antidepressants, serotonin syndrome is more likely to occur.

Serotonin syndrome symptoms can include:

  • coma
  • involuntary twitching or jerking
  • delirium
  • hyperthermia

Researchers temporarily associated tryptophan supplements with the syndrome of eosinophilia myalgia (EMS) in 1989. Symptoms including debilitating muscle pain and a high peripheral eosinophil count are triggered by EMS. A bad batch turned out to be the cause of EMS and not the result of the supplement itself.

It’s also important to remember that supplements are not currently regulated by the Food and Drug Administration (FDA).

There are, however, several different independent research companies looking at purity and potency supplements. In order to help reduce their risk of exposure to bad products or ineffectiveness, individuals should look for supplements that have certification from third party evaluators.

Other sources 

L-tryptophan is naturally present in many foods. Some food sources include:

  • turkey
  • tuna
  • nuts
  • seeds
  • bananas
  • dairy products
  • red meat
  • shellfish
  • soy products

The quantity of nutrients found in food is not likely to have any positive or negative effects on the sleep or mood of a person.

L-tryptophan alternatives

Another supplement that people can use to help relieve insomnia or sleep disorders is melatonin. Melatonin is a hormone that is released by the body to stimulate evening sleep and morning awakening.

An individual can try non-supplement-related sleep aids as well. Some measures that can help to make a better night of sleep easier include:

  • drinking warm milk
  • ensuring that the bedroom is cool and dark
  • exercising during the day

If they have other problems that they are considering using L-tryptophan to get advice on alternative therapies, people should speak to their doctor.

When to see a doctor

Before beginning any supplement, individuals should speak to their doctor. In particular, before taking L-tryptophan supplements, individuals who take antidepressants should speak to their doctor.

If they experience any odd symptoms after taking it, people should avoid taking the supplement and speak to their doctor.


L-tryptophan can be an effective aid to sleep and can also help with other conditions , such as chronic pain, depression , anxiety, or PMS.

The supplement, however, may not be for all, and for all conditions, it may not be beneficial. Before beginning a new supplement, people should speak to their doctor, and they should avoid taking it if they encounter any side effects.

In order to decide whether or not L-tryptophan is safe and effective in alleviating either of these conditions, further research is required.