L-Theanine

Buy L-Theanine: the amino acid found in tea, available in capsules, tablets and powder

L-theanine is an amino acid that occurs naturally in the leaves of the tea plant (Camellia sinensis). Unlike most other amino acids, it is not a building block of proteins, but a so-called free amino acid that is best known for its presence in green tea. In supplements, L-theanine is usually extracted from green tea or produced through fermentation. No approved health claims have been established for L-theanine; therefore, this page explains what it is, where it comes from and what to consider when choosing a supplement.

This collection includes standalone L-theanine products, such as Vit4ever capsules containing 750 mg of green tea extract and NOW Foods vegetarian capsules containing 200 mg of L-theanine plus inositol. It also features combination products from LUTO Supplements containing L-theanine, such as GABA effervescent tablets with L-theanine and vitamin B6, and ESN Caffeine + L-Theanine capsules and Boostea drink powder with caffeine and L-theanine from green tea.

What is L-theanine?

L-theanine (chemically: gamma-glutamylethylamide) is an amino acid with a structure similar to glutamine and glutamate. It was discovered in green tea in 1949 and contributes to tea's distinctive umami flavour. The "L" in its name refers to the natural form of the molecule; this form is used in virtually all supplements.

Where is L-theanine found naturally?

The main natural source is tea: green, black and white teas all contain L-theanine, although the amount varies depending on the type and preparation. A cup of tea usually provides several tens of milligrams. L-theanine is rarely found in food outside of the tea plant; an exception is the edible Boletus badius mushroom. Those seeking a higher or more consistent daily amount than tea can provide often choose a supplement.

Is theanine the same as theine?

No, and the names are often confused. Theine is simply another name for caffeine found in tea. L-theanine is a completely different substance: an amino acid without caffeine. Both occur naturally in a cup of tea, but in supplements they are separate ingredients that can be purchased individually or in combination.

L-theanine and caffeine: a common combination

Because L-theanine and caffeine occur naturally together in tea, they are also frequently combined in supplements. This collection includes the ESN Caffeine + L-Theanine capsules and Boostea powder, which can be prepared as a hot or cold drink. With such combinations, pay attention to the amount of caffeine per serving and your total daily caffeine intake from coffee, tea and other sources.

What forms and combinations are available?

Standalone L-theanine is primarily available as capsules, with doses varying by brand from 200 mg to 750 mg per daily serving. There are also combination products in which L-theanine is one of the ingredients, for example with GABA and vitamin B6, with herbs such as valerian, or with caffeine. The vitamin B6 in the GABA effervescent tablets contributes to normal psychological function and the normal functioning of the nervous system.

How much L-theanine per day?

There is no official recommended daily amount for L-theanine. Supplements usually contain daily doses between 75 and 750 mg, depending on the product and the combination of ingredients. If you are new to L-theanine, increase the dose gradually and always follow the directions for use and the recommended dosage on the packaging.

When should you take L-theanine?

There is no fixed time that applies to everyone; when you take L-theanine depends on the product. With combination products containing caffeine, pay attention to your total daily caffeine intake. L-theanine can be taken with or without food. Always follow the directions on the packaging for the recommended time and frequency.

What to consider when buying L-theanine?

First, check the dose per capsule or serving and the number of servings per package; this allows you to fairly compare the price per daily serving. Also check the source (green tea extract or fermented L-theanine), whether the product is vegan or vegetarian, and which excipients have been used. If you prefer to use L-theanine on its own, choose a single-ingredient product; if you are looking for a complete formula, a combination product with, for example, GABA or caffeine may be more convenient.

Explore our related collections too: GABA, Caffeine, Amino Acids and L-Tryptophan.