Drugs & toxicology

Lamotrigine unit converter

Anticonvulsant/mood-stabilizer drug level for therapeutic drug monitoring

Also known as: Lamictal, LTG

Converter

Enter a value in any unit and all other units fill in.

µg/mL µmol/L mg/dL µg/dL µg/L

Worked example

9 µg/mL (middle of the reference range) = 35.1 µmol/L

Conversion formulas

µmol/L	µmol/L = µg/mL × 3.905	µg/mL = µmol/L × 0.2561
mg/dL	mg/dL = µg/mL × 0.1	µg/mL = mg/dL × 10
µg/dL	µg/dL = µg/mL × 100	µg/mL = µg/dL × 0.01
µg/L	µg/L = µg/mL × 1000	µg/mL = µg/L × 0.001

Reference range

Unit	Adults
µg/mL	3 – 15
µmol/L	11.71 – 58.57
mg/dL	0.3 – 1.5
µg/dL	300 – 1500
µg/L	3000 – 15 000

Source: Reference ranges for antiepileptic drugs revisited (ILAE ranges), Drug Des Devel Ther 2018 · Last reviewed: 2026-10-14

Note from the source: ILAE 2008 range 3-15 mg/L (10-60 µmol/L); some centres use 3-13 mg/L

Frequently asked questions

How do I convert Lamotrigine from µg/mL to mg/dL?

mg/dL = µg/mL × 0.1. In the other direction: µg/mL = mg/dL × 10.

What is the reference range of Lamotrigine?

For adults the range is 3 – 15 µg/mL (Reference ranges for antiepileptic drugs revisited (ILAE ranges), Drug Des Devel Ther 2018). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for Lamotrigine?

Common units are µg/mL, µmol/L, mg/dL, µg/dL, µg/L.