Taking Collagen That Contains Tryptophan And Tyrosine With Lexapro

In our latest question and answer, our pharmacist discusses the combination of tryptophan-containing collagen and Lexapro (escitalopram).


Can you take collagen that contains tyrosine and tryptophan while on Lexapro (escitalopram)?

Asked by Marwa On Oct 14, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Oct 14, 2022
Last updated Oct 14, 2022

Key points

  • Collagen doesn't naturally contain the amino acid tryptophan, so it is often added to collagen supplements.
  • There is a potential interaction between tryptophan and SSRIs (selective serotonin reuptake inhibitors) like Lexapro since tryptophan is a serotonin precursor, and Lexapro affects serotonin concentrations and its receptors.
  • We consume tryptophan in our diet and the small amounts added to collagen supplements would be very unlikely to cause a clinically significant interaction. There is more concern with the dosages contained in standalone tryptophan supplements.
  • Anytime multiple drugs/supplements affect serotonin, there is an increased risk of a rare, but serious condition known as serotonin syndrome.
  • Always let your doctor know about supplements you plan on taking with your existing prescription medication so you can be appropriately monitored.


First and foremost, collagen does not interact with Lexapro (escitalopram) and both are considered safe to use together (we have written about this topic before, which can be found here). The same goes for tyrosine with Lexapro. There is some concern, however, about taking tryptophan-containing supplements with SSRIs (selective serotonin reuptake inhibitors) like Lexapro.

Although tryptophan is a naturally occurring amino acid, one we get in our everyday diet, the high doses contained in some supplements have been rarely linked to an increased risk of a condition known as serotonin syndrome when given with other drugs that affect serotonin, like Lexapro.

As a general rule of thumb, tryptophan (often used in supplements in the L-tryptophan form) shouldn't be taken with SSRIs like Lexapro unless recommended by your doctor.

Having said this, the risk of a rare condition like serotonin syndrome occurring by combining Lexapro and a collagen supplement with added tryptophan would be quite rare, and I could not find a single case study where this occurred (I have only seen studies with large doses of tryptophan potentially causing problems).

I discuss this more in the next sections.

Collagen Doesn't Naturally Contain Tryptophan And Is Sometimes Added

Tryptophan is very commonly added to collagen supplements in small amounts because collagen is an incomplete protein (i.e. does not contain all the essential amino acids) and does not naturally contain it. The amount added to collagen supplements is generally low, around 30-80 per serving.

Compare this with the fact that most stand-alone tryptophan supplements contain 500mg-1000mg per serving, and we're talking about a much smaller amount in your collagen supplement.

Again, tryptophan is an essential amino acid, and we consume it in our diet regularly (we have to, as our bodies cannot synthesize it), so in a sense, everyone taking Lexapro is already taking it in combination with tryptophan. We're really more concerned about dosing here.

Why There Is Concern With L-Tryptophan And Lexapro

The mechanism behind the antidepressant effects of Lexapro isn't fully understood but involves both increases in available serotonin in certain parts of the brain as well as a change in the balance of serotonin receptors in the brain.

L-tryptophan is an essential amino acid and when consumed (either via diet or as a supplement), is absorbed and converted to 5-hydroxytryptophan (5-HTP) and finally to serotonin (5-hydroxytryptamine). It is also metabolized to a variety of other compounds, including melatonin.

Caution is always recommended when combining drugs that have serotonergic effects and should not be done unless under the direction of your doctor.

The prescribing information for Lexapro specifically warns against the use of serotonin precursors like L-tryptophan:

Serotonin Syndrome: Patients should be cautioned about the risk of serotonin syndrome with the concomitant use of Lexapro with other serotonergic drugs including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines and St. John’s Wort, and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid)

Lexapro Prescribing Information

This potential interaction would apply to all SSRI drugs, including:

  • Prozac (fluoxetine)
  • Zoloft (sertraline)
  • Luvox (fluvoxamine)
  • Lexapro (escitalopram)
  • Celexa (citalopram)
  • Paxil (paroxetine)

Serotonin Syndrome

Several studies have warned against the use of SSRI antidepressants (like Lexapro) with drugs or supplements that increase serotonin levels. This would include L-tryptophan and 5-hydroxytryptophan (5-HTP).

With L-tryptophan specifically, although it appears to be rare, case reports have been published in which l-tryptophan in combination with an SSRI has produced serotonin syndrome, which is essentially serotonin toxicity from high concentrations.

Serotonin syndrome is characterized by a range of symptoms, including:

  • Increased body temperature
  • Increased blood pressure
  • Muscle spasms and rigidity
  • Dizziness
  • Increased heart rate
  • Mental status changes
  • Death (has been reported but is rare with appropriate treatment)

Serotonin syndrome, although rare, is serious if it occurs and must be treated immediately.

How Likely Is An Interaction To Occur Between Tryptophan-Containing Collagen And Lexapro?

As mentioned, the risk of any interaction occurring between Lexapro and a collagen supplement that contains added tryptophan is quite unlikely due to the small amounts added. You generally would be consuming no more tryptophan than you would be in your normal diet.

There is more concern with the amount of tryptophan combined in stand-alone dietary supplements, and even then, the risk of serotonin syndrome occurring is low. 

Nevertheless, it is important to always monitor for side effects when you take medication, and always speak with your doctor before combining new supplements with your existing prescription medication so you can be appropriately monitored.

Final Words

Thanks for reaching out and I hope this was helpful!


  • Effects and side effects associated with the non-nutritional use of tryptophan by humans, PubMed
  • The Antidepressant Effect of L-Tyrosine-Loaded Nanoparticles: Behavioral Aspects, PubMed
  • Significant Amounts of Functional Collagen Peptides Can Be Incorporated in the Diet While Maintaining Indispensable Amino Acid Balance, PubMed
  • Lexapro Prescribing Information, AccessFDA
  • Selective Serotonin Reuptake Inhibitors (SSRI) Pathway, PubMed
  • L-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications., PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at Hello@HelloPharmacist.com! You can also connect with Dr. Brian Staiger on LinkedIn.

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