L-Theanine - The hidden treasure of green tea
L-theanine powder from RawSeries is a dietary supplement based on green tea.
The green tea extract used as the raw material source of the theanine has been processed to the point of purifying 100% of its L-theanine amino acid content, without residues or collateral nutrients from the tea leaf at origin. Theanine is an amino acid with enantiomerism, with only its Levo- (L-) stereoisomeric configuration being nutritionally relevant. Its behavior as a non-proteinogenic amino acid capable of crossing the blood-brain barrier, structurally similar to glutamine, has sparked scientific interest to understand the extent of its properties.
If you’re looking for pure theanine, you won’t find a better option.
What properties does green tea theanine have?
L-Theanine as an amino acid has gained great interest in recent decades, since green tea is a traditionally used plant, and science tries to understand what elements it has to exert those properties in the human body. Among its compounds, caffeine and catechins stand out, but L-theanine also received special attention due to its structural characteristics and high presence in the leaves.
Since it is very water-soluble and stable at high temperatures, narrative reviews suggest that much of the properties of tea infusions could be due to the large amount of theanine infused in the water. On the other hand, theanine is especially concentrated in the matcha variety of green tea, which in turn has different uses and nutritional implications compared to traditional tea leaves. It has been hypothesized that this difference between matcha green tea and regular green tea may be due to its higher L-theanine content (which is essentially why matcha tea has a more umami flavor, thanks to theanine).
The theanine stimulates alpha brain waves, which is associated with a relaxed but alert mental state. That’s why it promotes rest with a relaxed state.
How does HSN turn an amino acid into something unique?
1. Origin and purity
The most classic way to obtain L-theanine is through synthesis. In a lab, through fermentation or chemical intervention, a theanine molecule can be created. But why synthesize something that nature offers us? Doesn’t it make more sense and align better with our responsibility as people to use the natural sources of the amino acid we’ve been using for centuries? At HSN, we believe so, we advocate for natural options, and that’s what we show in our L-theanine. Let us explain the process!
Green tea is naturally grown, like the green tea leaf powder you can buy to prepare infusions, but in our case, we take more care in selecting which leaves we want, choosing only the young leaves, which are richest in L-theanine. Once harvested, we dry and grind them to make the extraction more efficient.
The dry green tea leaf powder is mixed with hot water, but in our case, we don’t use boiling water because although L-theanine can theoretically withstand it, we prefer to use milder protocols to avoid any degradation. Since theanine is very water-soluble, it transfers quickly to the water, resulting in a extract of water-soluble green tea compounds.
We separate the elements that remain in the water; in this case, we want only a pure presentation of theanine, so polyphenols, catechins, and caffeine are unwanted. For this, we follow filtration procedures that, thanks to differences in the molecules of each compound, allow us to separate them until we maximize theanine concentration. After this, we perform a specific purification using more precise technologies, taking advantage of electrical charge and affinity for compounds to isolate 100% pure theanine.
Simply after that, we have a pure theanine solution, which we crystallize, recrystallize, spray dry, and analyze for purity so you receive at home a presentation of pure theanine powder, with no blends or residual elements.
2. Particle size
L-Theanine powder has a specific particle size, and this is something not all companies control; in many cases, as long as it’s 'powder,' it’s fine and no mesh controls are done to determine particle size. At HSN, we do, because while this doesn’t significantly impact the properties of L-theanine, it does affect the experience you get when using it; different particle sizes dissolve and feel different in the mouth.
In our case, we have micronized the powder to guarantee a finer appearance and therefore maximum solubility, instantly, without lumps, making it comfortable to use whether you want to mix it simply in water and take it alone, or combine it with other compounds like caffeine or melatonin. Its finer pulverization makes the flavor of theanine more noticeable due to its greater surface area, which is why at HSN we purify our raw material to the max, because theanine naturally has a mild taste, tending to neutral and very easy to take; if you’ve come across theanine powders with a characteristically bitter or acidic taste, they’re not pure theanine.
3. Quality guarantees
At HSN, we manufacture our own products, which is why we can guarantee premium quality at a fair price that defines us.
Instead of outsourcing manufacturing responsibility to external companies, which can always have production process issues you can’t control internally, we handle everything 'in house.' Thanks to this, we have absolute custody from the arrival of raw 'bulk' material at our warehouses to the shipment of the packages you receive at home.
The manufacturing process is certified by companies that guarantee our procedures follow the best quality and safety manufacturing controls. You’ll find all this in HSN products.
Powder vs capsules. Which to choose?
At HSN, you can find different presentations for the same compound. You’ll find L-Theanine in capsules from HSN, here.
Capsules have the advantage of being predosed, so you don’t have to fuss with measurements; each capsule contains the amount of theanine indicated. On the other hand, they’re easy to carry since they don’t stain and can be stored in a pillbox or any container conveniently. However, powder is ideal for:
- Customizing the dose: Thanks to the powder format, you can split your daily dose however you prefer.
- Versatility: Capsules are designed to be taken as is; if you want to combine theanine with other compounds, powder is the best option.
- Transparency: We know some people still doubt the transparency of supplement companies. Powder format lets you see for yourself that the theanine you buy is 100% L-Theanine, no tricks.
L-Theanine vs D-Theanine
Theanine exists in two different chemical forms: L-Theanine and D-Theanine. Both are enantiomers, meaning molecules with the same composition but different spatial arrangement, like mirror images. This difference, though it may seem minimal, is crucial for the body because it determines whether the molecule 'fits' into biological structures that allow it to have an effect.
L-Theanine is the form naturally found in green tea leaves. Our body is adapted to recognize and use this version, just like all amino acids that make up human proteins, which are always of the L series. In contrast, D-Theanine is not naturally found in tea. It only appears when theanine is chemically synthesized without proper process control, resulting in mixtures of both forms (called a racemate or DL-Theanine). The problem is that D-Theanine doesn’t fit into receptors or transporters in our body, so it doesn’t produce the effects that L-Theanine does. Practically, it’s considered inactive biologically.
For all these reasons, when looking for a quality dietary supplement, it’s essential to check that it’s formulated with pure L-Theanine. If the label only says “theanine” without specifying the form, there’s a chance the product contains some D variant, reducing its real effectiveness. This distinction isn’t just a technical detail: it’s the key that determines if the product is optimal or not. At HSN, we have 100% L-Theanine.
What to combine theanine with?
Theanine is an amino acid that, depending on your interest in it, has some well-known and quite standard combinations with other dietary supplements.
- Caffeine: Caffeine is undoubtedly the compound most used together with L-theanine. This is due to studies evaluating the positive effects of combining both nutrients in the same intake.
- GABA and Melatonin: Many people who use theanine take it at night, specifically combined with these compounds.
- Evoptogen: HSN’s adaptogenic formula, a classic combination.
Don’t forget you can find L-Theanine as part of the Smart Caffeine and Stress Care formulas.
What does L-Theanine powder taste like?
L-Theanine powder has a neutral taste.
Scientific studies to learn more
- Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience, 13(6), 283–290.
- Hidese, S., Ogawa, S., Ota, M., Ishida, I., Yasukawa, Z., Ozeki, M., & Kunugi, H. (2019). Effects of L-Theanine administration on stress- related symptoms and cognitive functions in healthy adults: A randomized controlled trial. Nutrients, 11(10), 2362.
- Kimura, K., Ozeki, M., Juneja, L. R., & Ohira, H. (2007). l-Theanine reduces psychological and physiological stress responses. Biological Psychology, 74(1), 39–45.
- O’neill Rothenberg, D., & Zhang, L. (2019). Mechanisms underlying the anti-depressive effects of regular tea consumption. Nutrients, 11(6).
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