L-Theanine & Caffeine


L-Theanine & Caffeine together form a synergistic combination without the unwanted effects of overstimulation.

In these times, when we are all looking for natural ways to improve our health and wellbeing, AvantVital offers the perfect combination of L-Theanine and Caffeine. This synergistic combination is also known as the ‘Beginner’s Stack’ among nootropic users.

Discover the benefits of L-Theanine & Caffeine from AvantVital

  • Optimal ratio of the two substances.
  • L-Theanine extracted from Green tea.
  • Suitable for vegetarians.
  • Free from unhealthy additives.
  • Easy to swallow capsule size.

Available in convenient resealable stand-up pouch with 90 capsules containing 200 mg L-Theanine and 100 mg Caffeine per capsule.

In stock

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What are L-Theanine & Caffeine?

L-Theanine is an amino acid primarily found in the leaves of green tea and in smaller amounts in black tea and certain mushrooms. This natural substance has been used for centuries in traditional Chinese and Japanese medicine.

Caffeine, on the other hand, is a well-known stimulant that is consumed worldwide, primarily in coffee, tea, chocolate, and energy drinks. Caffeine is extracted from coffee beans, tea leaves, and cocoa beans and has a long history in cultures around the world, including Ethiopian and South American traditions, where coffee and tea drinking is deeply embedded in social ceremonies.

While L-Theanine and Caffeine have a long tradition in traditional medicine, it’s important to note that this doesn’t automatically mean their health benefits are recognized according to EU regulations.

The combination of L-Theanine and Caffeine in supplement form is a modern usage of these ancient ingredients. This combination is valued for the unique way they complement each other: L-Theanine can take the edge off the stimulating effects of Caffeine, allowing the user to experience calm alertness without the jitters or restlessness often associated with Caffeine intake.

Discover the benefits of L-Theanine & Caffeine from AvantVital

Due to strict EU regulations, we can only provide limited information about this supplement. We are only allowed to mention claims that are officially approved and listed in the EU database. Unapproved scientific results may not be shared.

Available in a convenient resealable stand-up pouch with 90 capsules, each containing 200 mg L-Theanine and 100 mg Caffeine.


L-Theanine is one of many amino acids, but it is distinguished by not being involved in protein building, which most amino acids do. This type of amino acid is classified as a non-proteinogenic amino acid. It is primarily present in green tea and contributes to the unique flavor. In the human body, L-Theanine is involved in various processes and affects various body functions, consistent with the general properties of amino acids.

Caffeine, on the other hand, is a stimulating substance, specifically known as a xanthine alkaloid. This is a type of compound that occurs naturally in various plants and is known for its stimulating effects. In the human body, caffeine primarily works by blocking adenosine receptors, a process that can affect alertness and shorten reaction time.

Why buy L-Theanine & Caffeine from AvantVital?

Easy Intake: One capsule for the optimal ratio

The L-Theanine & Caffeine supplement from AvantVital makes intake easy by combining both substances in the optimal ratio in one capsule. Additionally, the L-Theanine is extracted from a natural source, namely green tea. It is available in a convenient, resealable stand-up pouch with 90 capsules, each capsule containing 200 mg L-Theanine and 100 mg Caffeine.

Suitable for vegetarians, easy to swallow & free from unhealthy additives

L-Theanine & Caffeine from AvantVital is encapsulated in vegan HPMC capsules. HPMC stands for hydroxypropyl cellulose and is made from cellulose. The substance is extracted from wood. Cellulose is actually an indigestible plant fiber and is recognized as such by our body. HPMC is similar to cellulose but is much more soluble and is considered safe for human consumption.

A commonly used capsule size is #00, which stands for 24 mm length, 9 mm diameter. There is a large group of people who find this capsule size difficult to swallow. The capsules we use for L-Theanine & Caffeine are size #1, 19 mm length, 7 mm diameter. By avoiding unnecessary additives and spreading the reference intake doses over more capsules, we can use this easy-to-swallow size.

AvantVital’s L-Theanine & Caffeine contains minimal amounts of gluten-free organic rice flour and magnesium stearate, used as filler and anti-caking agent, respectively, to ensure a consistent dosage in each capsule, free from unnecessary additives.

Use & Ingredients

The ideal dosage of L-Theanine & Caffeine can vary depending on personal needs; generally, a dosage of 200 mg L-Theanine and 100 mg Caffeine per day is recommended. Since our capsules contain this exact ratio, we advise using one capsule daily, fitting your individual needs and lifestyle.

L-Theanine & Caffeine can be taken with or without food. However, some users prefer to take it with food to prevent any stomach upset. It’s important to listen to your body and adjust intake to what feels best for you.

The timing for taking the capsule is flexible; you can take the capsule in the morning, afternoon, or at any other time that fits best with your daily routine, depending on how your body responds to the supplement.

Continuous use of L-Theanine & Caffeine is possible, but it may also be beneficial to take a break after several months of consistent use. This can help to maximize effectiveness and give your body time to rest.

Before starting to use L-Theanine & Caffeine, especially if you are pregnant, breastfeeding, taking medication, or have an existing health condition, we recommend consulting with a healthcare professional to avoid potential negative interactions.

Pay attention to how your body reacts to the supplement. If you experience any undesirable side effects, stop using it and consult a healthcare professional.

The supplement should be stored in a cool, dry place and kept out of reach of children to maintain quality and prevent unintended use.

Side Effects

L-Theanine & Caffeine is generally considered safe when used within the recommended dosages. However, as with all supplements, some users may experience mild side effects. With caffeine use, some people might experience mild stomach or intestinal discomfort, such as bloating, diarrhea, or stomach cramps. In addition, caffeine in higher dosages can cause insomnia or nervousness.
These side effects are generally mild and not everyone experiences them. However, if you experience severe side effects, it is advisable to stop intake and seek medical advice. It is also wise to consult a healthcare professional before starting L-Theanine & Caffeine, especially if you are pregnant, breastfeeding, taking medication, or have a medical condition.


Interactions between L-Theanine, Caffeine, and medications are not extensively documented. Therefore, people taking medication should be cautious and consult a healthcare professional before starting new supplements, including L-Theanine & Caffeine. This is particularly important for people taking medication that affects blood pressure, blood sugar levels, or sleep patterns, as caffeine can potentially interact with these medications. A consultation with your doctor or a qualified healthcare professional can help ensure safe and appropriate use of L-Theanine & Caffeine in your specific situation and prevent potential negative interactions with medications.


This product is not intended to diagnose, treat, cure, or prevent any diseases. This supplement should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Do not exceed the recommended daily dosage. Keep out of reach of children. Consult your doctor or healthcare provider before using this supplement, especially if you are pregnant, breastfeeding, taking medication, or have a medical condition.

When sharing information about well-being and health, we encounter limits set by European and Dutch regulations. These restrictions are there to protect you and ensure that we do not make unfounded health claims. It is important to note that, although traditional or non-Western medical practices have their own place and respect, EU legislation requires that health claims must be based on recognized scientific evidence. Within these frameworks, we strive to be as informative as possible, without crossing the boundaries of the law.


Content: 90 capsules
Daily dosage: 1 capsule
Ingredients per capsule
RI %
200 mg
100 mg
*Reference intake not established

Do not exceed the recommended daily intake. Food supplements are not a substitute for a varied diet and healthy lifestyle. Store in a dry, cool place and keep out of reach of children.
Batch - 240220
Best before end - 2026/08/14


Daily Recommended Dosage: 1 capsule

Ingredients per 1 capsule

100 mg Caffeine Anhydrous
200 mg L-Theanine (from green tea extract)

Gluten-free organic rice flour (filler)
Magnesium stearate (anti-caking agent)
Hydroxypropylmethylcellulose (Vegan/ HPMC) capsule

Instructions for use

High caffeine content. Do not use if you are under 18, or if you are pregnant or breastfeeding. Do not use if you have high blood pressure or medical complications. Always consult an expert before using new food supplements. A healthy lifestyle is important, as is a varied and balanced diet for which supplements are no substitute. Do not exceed recommended dosage.

Recommended Dosage: As a dietary supplement for adults, 1 capsule daily.

Keep cool, dry and closed.