Thymine

Optimal result: 0 – 0.56 mmol/mol creatinine

- Slightly elevated urinary thymine has no clinical significance.
- High values are associated with inflammatory diseases and cancer. 

Elevated pyrimidines and elevated thymine have been reported in dihydropyrimidine dehydrogenase deficiency, a rare genetic disease, which has been associated with seizures and autism.

A pyrimidine (DNA building block) that is elevated in the genetic disease dihydropyrimidine dehydrogenase deficiency. In this genetic disease, the pyrimidine uracil is also elevated.

- Thymine is one of the five bases used to build nucleic acids.
- It is also known as 5-methyluracil or by the abbreviations T or Thy.
- Thymine is found in DNA, where it pairs with adenine via two hydrogen bonds. In RNA, thymine is replaced by uracil.

Thymine is one of the four Pyrimidines/nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T.

Uracil = 2,4-dioxy pyrimidine
Thymine = 2,4-dioxy-5-methyl pyrimidine
Cytosine = 2-oxy-4-amino pyrimidine
Orotic acid = 2,4-dioxy-6-carboxy pyrimidine

Cytosine is found in both DNA and RNA. Uracil is found only in RNA. Thymine is normally found in DNA. Sometimes tRNA will contain some thymine as well as uracil.

Thymine is also called 5-methyluracil or it may be represented by the capital letter "T" or by its three-letter abbreviation, Thy.

The molecule gets its name from its initial isolation from calf thymus glands by Albrecht Kossel and Albert Neumann in 1893. Thymine is found in both prokaryotic and eukaryotic cells, but it does not occur in RNA viruses.

Thymine
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 Thymine — 10,000+ markers explained
One Thymine 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