Drug & supplement interaction

L-tryptophan + Aripiprazole Lauroxil

Aripiprazole Lauroxil brand names: Aristada, Aristada Initio Kit.

Major Interaction
Medically reviewed by · Updated September 2026
The bottom line Major

Aripiprazole Lauroxil falls into 2 drug categories that L-tryptophan can interact with; the most serious is rated major. Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.

Read the full interaction report
SeverityMajor
LikelihoodProbable
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

L-tryptophan and Aripiprazole Lauroxil

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

L-tryptophan interacts with whole categories of medication. Aripiprazole Lauroxil falls into 2 of those categories, so it can interact with L-tryptophan in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Major).

Major

CNS DEPRESSANTS

1 of 2

Why this applies to Aripiprazole Lauroxil

Aripiprazole Lauroxil falls under CNS DEPRESSANTS — the group L-tryptophan interacts with.

Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Clinical research shows that L-tryptophan can cause fatigue and drowsiness.
Severity Major Likelihood Probable Evidence B

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Aristada is a long-acting injectable form of aripiprazole that your doctor gives every few weeks to help manage schizophrenia. On its own, it can sometimes make people feel sleepy or slowed down. L-tryptophan can also cause fatigue and drowsiness, so taking the two together may add up and leave you feeling more tired, foggy, or sluggish than usual.

This isn't about one changing the other's levels in your blood. It's simply two things that can both calm the nervous system, so the sleepiness can stack. The concern here is mostly theoretical and based on limited research, so don't panic. Just be cautious about driving or doing anything that needs full focus, and check with your pharmacist or doctor before adding tryptophan.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lieberman HR, Corkin S, Spring BJ. The effects of dietary neurotransmitter precursors on human behavior. Am J Clin Nutr 1985;42:366-70. PubMed
Moderate

SEROTONERGIC DRUGS

2 of 2

Aripiprazole Lauroxil also falls under SEROTONERGIC DRUGS.

Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
L-tryptophan is a precursor to serotonin. Theoretically, combining serotonergic drugs with L-tryptophan might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thinking behind this one. Aripiprazole lauroxil (Aristada) is a long-acting injection that nudges serotonin and dopamine signaling as part of how it treats schizophrenia. L-tryptophan is a building block your body turns into serotonin. Put the two together and, in theory, you could stack a little extra serotonin activity on top of what the medication already does.

I want to be honest about the strength of this: it's theoretical, based on how these substances work rather than reports of it actually happening. The concern would be rare but serious serotonin syndrome, which can show up as agitation, fast heartbeat, sweating, shivering, muscle twitching, or confusion. Since the injection stays in your body for weeks, please check with your pharmacist or prescriber before adding tryptophan, and don't change your shot schedule on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Messiha FS. Fluoxetine: adverse effects and drug-drug interactions. J Toxicol Clin Toxicol 1993;31:603-30. PubMed
  2. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

L-tryptophan Also Interacts With Other Medications

L-tryptophan has 247 major, 146 moderate known drug interactions in our database — the Aripiprazole Lauroxil one above is among them. If you take anything else, check it against the full list below.

Major 247 Moderate 146 No known interaction 2,437 (incl. Aripiprazole Lauroxil)
Taking anything else?

Check Another of Your Medications Against L-tryptophan

Covers the 2,830 medications we’ve checked against L-tryptophan. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Aripiprazole Lauroxil

This page covers L-tryptophan only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aripiprazole Lauroxil page lists 233 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 16 major · 187 moderate · 30 minor.

From our pharmacist’s overview on the Aripiprazole Lauroxil page

“Aripiprazole lauroxil (Aristada) is a long-acting antipsychotic injection, and because each dose keeps working for weeks, a bad supplement pairing cannot be undone by skipping a pill. So the 16 major-rated entries among its 233 interactions on file deserve to be understood first.”

Reviewed by 2 · Jul 18, 2026

Open the Aripiprazole Lauroxil interaction page

One more smart check

Taking L-tryptophan as Part of a Dietary Supplement Product? Check It for Interactions

We hold 5 real supplement products containing L-tryptophan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-tryptophan. Your product may carry other ingredients that interact with Aripiprazole Lauroxil too, on top of L-tryptophan — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where L-tryptophan and Aripiprazole Lauroxil Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement L-tryptophan
Steady interest

#917 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Aripiprazole Lauroxil
Top half

#709 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About L-tryptophan

What is L-tryptophan?

L-tryptophan
  • Sleep problems
  • Low mood and depression
  • Anxiety
  • Premenstrual symptoms
  • Appetite and food cravings

L-tryptophan is an essential amino acid the body uses to make serotonin and melatonin, and people take it to support sleep and mood. The evidence for supplement use is limited and mixed, and there are real safety concerns, so talk to a pharmacist or doctor before trying it.

Read the full L-tryptophan monograph & all interactions
Medication

About Aripiprazole Injection

What Is Aripiprazole Injection Used For?

Brand names: Aristada, Aristada Initio Kit

Aripiprazole injection is used to treat schizophrenia and to provide maintenance treatment for bipolar I disorder in adults. Different injectable products carry these approvals.

Abilify Asimtufii is approved for the treatment of schizophrenia in adults and as maintenance monotherapy for bipolar I disorder in adults. Aristada is approved for the treatment of schizophrenia in adults, with Aristada Initio used specifically to help start Aristada therapy.

See full Aripiprazole Injection drug information
Keep checking

Other Drugs & L-tryptophan

Browse every other medication we’ve checked against L-tryptophan — both the ones with a known interaction and the ones without. Select any drug for the full detail.

247Major
146Moderate
0Minor
2,436No known interaction
247 Major 146 Moderate 2,436 No interaction
Major

247 interactions

Showing 60 of 247 major interactions — see all 247 on the L-tryptophan page.

Moderate

146 interactions

Showing 60 of 146 moderate interactions — see all 146 on the L-tryptophan page.

No interaction 2,436 drugs checked — show the list

We also checked L-tryptophan against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,436 medications checked with no known interaction — see the full L-tryptophan list.

See the full L-tryptophan interactions page
See every supplement checked against Aripiprazole Lauroxil, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
L-tryptophan monograph › Uses, safety, and every drug interaction in one place Aripiprazole Lauroxil supplement interactions › Every supplement checked against Aripiprazole Lauroxil, ranked by severity Aripiprazole Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking L-tryptophan and Aripiprazole Lauroxil Together: Common Questions

Can you take L-tryptophan with Aripiprazole Lauroxil?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for L-tryptophan and Aripiprazole Lauroxil?
Aripiprazole Lauroxil belongs to more than one drug category, and L-tryptophan interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the L-tryptophan and Aripiprazole Lauroxil interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.