Login Pro Login Sign Up
Sign Up
Home › Research › ZRT Laboratory (Urinary Neurotransmitters): Tryptophan
ZRT Laboratory (Urinary Neurotransmitters)

Tryptophan

Optimal result: 3970 – 8450 µg/g creatinine
ZRT Laboratory
By Healthmatters Editorial Team
Peer-reviewed sources

Tryptophan is high with tryptophan supplementation and in some individuals with a high protein diet. Clinically, high tryptophan is associated with headaches and selective serotonin reuptake inhibitor treatment.

Tryptophan excretion is low in patients with autism spectrum disorder, and in some individuals with a low protein diet.

Clinically, low tryptophan is associated with aggression, depression, impulsivity, with fructose malabsorption, Alzheimer’s disease, Crohn’s disease, multiple sclerosis, pain disorders like fibromyalgia, and diabetes.

Tryptophan is an amino acid that generates serotonin, melatonin, and kynurenine derivatives.

Tryptophan is an amino acid that generates serotonin, melatonin, and kynurenine derivatives.

Organize and understand all your lab results

$15 /month
or $79/year — for your whole history →
Every marker charted over time
Any lab — with custom ranges
Export & share with your doctor
Add unlimited reports — free
★★★★★

“Once I could see all my markers trending together instead of one number in isolation, everything finally made sense.”

Barbara · Member since 2023
Start organizing — $15/mo → See all plans →
Secure checkout via Stripe · GDPR & HIPAA
For Health Professionals Healthmatters Pro Multiple clients’ results in one dashboard. See Pro plans →
Tryptophan
Healthmatters dashboard showing biomarker trend graph

Every lab result you’ve ever had, charted and explained.

Healthmatters is a tracker for your lab results. Upload a report from any lab, any country — every marker charted and explained.

Start with my report →
Beyond Tryptophan — 10,000+ markers explained
One Tryptophan result tells you where you are. Your history tells you where you’re heading. Upload your past lab reports and see this marker — and every marker on them —every marker charted against your own lab’s ranges.
Start with this report →
Healthmatters timeline preview showing biomarker trends over time
Clinical Sources & References

All our content is backed by peer-reviewed studies, academic research, and trusted medical sources. We’re committed to accuracy and transparency — see our editorial policy for details.

Article Review Log
Written by Healthmatters Editorial Team
Healthmatters Lifetime Plan

Pay $250. Track your health forever

One payment. No renewals. Yours for life.

10,000+ biomarkers explained · trends over time

See other plans →
Secure checkout via Stripe · GDPR & HIPAA
We accept results from any lab
LabCorp Quest Diagnostics Genova Diagnostics DUTCH Test Doctor's Data Vibrant America ZRT Laboratory Cyrex Labs + any other lab

What members are saying

★★★★★ 10,000+ happy members
★★★★★

"Watching my numbers move over the years — instead of forgetting last time's results — completely changed how I manage my health."

Daniel
Member since 2022
★★★★★

"Living across several countries made keeping my lab results organized a real challenge. Healthmatters brought my results from the USA, Spain, and Germany together — 20 years of history, with long-term trends instead of scattered reports."

Ben
Member since 2021 · tracks across countries
★★★★★

"Standard lab ranges are too wide for how I practice — 'normal' isn't optimal. I set my own bands, so a client sees yellow before a marker goes officially out of range. That's the conversation I want to be having."

Dr. Alexandra
Functional medicine · 6 yrs on Pro