# L-theanine: what the research tells us

Canonical source: https://www.trynula.co/blogs/reset-library/what-l-theanine-actually-does

July 2, 2026

updated September 13, 2026

L-theanine is one of the ingredients in Nula Calm Gum. It is an amino acid found in tea, and researchers have studied it separately from this product.

## A closer look at one trial

In a [2019 randomized, placebo-controlled crossover trial by Hidese and colleagues](https://pmc.ncbi.nlm.nih.gov/articles/PMC6836118/), 30 adults took L-theanine or placebo for four weeks each. Some sleep measures improved more during the L-theanine period, but not every comparison with placebo was statistically significant.

That small study is a reason to keep researching the ingredient. It does not establish a guaranteed result for everyone, an immediate effect, or how Nula is absorbed.

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## Ingredient research and product evidence

The trial did not test Nula Calm Gum. Different amounts, formulations, and study settings cannot be assumed to produce the same experience.

For context on the format, read [why Nula comes in gum form](https://www.trynula.co/blogs/reset-library/why-gum-works-faster-than-a-pill). The [ingredient overview](https://www.trynula.co/science) explains what is in Nula.

_100mg per serving._ [calm gum →](https://www.trynula.co/products/calm-gum)

what's your stress type?

[take the 60-second quiz →](https://www.trynula.co/quiz)

## Nula Calm Gum

100 mg L-theanine + 50 mg GABA in every piece. caffeine-free. chew 1–2 pieces for at least three minutes.

[shop calm](https://www.trynula.co/products/calm-gum)

## More from the Reset Library

- [Why Nula comes in gum form](https://www.trynula.co/blogs/reset-library/why-gum-works-faster-than-a-pill)