Reviews Stacks

Axon Labs’ NEXUS Nootropic Stack, My Experience (Review)

Formulating nootropic stacks can sometimes be a difficult or time-consuming process. While the research that goes into drug combinations and synergy can be rewarding and even enjoyable, sometimes it’s difficult to find the right information on specific nootropics. Even when the right ratios are figured out, making multiple capsules of a certain stack can be even more time-consuming than the research.

Although pre-made nootropic stacks can be more expensive than buying bulk powder, they are sometimes well worth the price. Nootropic blends can be specially formulated by individuals with a deep understanding of neuroscience, giving the best cognitive benefits possible. Axon Labs’ NEXUS Nootropic Stack is an encapsulated blend of aniracetam, CDP-choline, phosphatidylserine, and Pycnogenol. The serving size is two capsules, and each serving contains 1.250 mg of this nootropic blend. Although the amounts of each component are not specifically listed, we can make a plausible assumption based on standard dosages for these compounds.


The key component to this blend is aniracetam, a well-respected nootropic that is gaining popularity for its unique ability to improve cognition and reduce anxiety at the same time. A more detailed look at aniracetam’s mechanism can be found here on our site. Essentially, aniracetam modulates the action of glutamate (an excitatory neurotransmitter) by reducing glutamate receptor desensitization. [1] This, in theory, would improve memory and strengthen the connections between neurons. Aniracetam is also unique among racetams in the fact that it has the ability to reduce feelings of anxiety and depression. It most likely accomplishes this by means of serotonergic, dopaminergic, and cholinergic mediation. [2]

CDP-choline (also known as citicoline) is a source of choline that also serves as a prodrug to uridine, another nootropic supplement. Choline is essential for the production of the neurotransmitter acetylcholine in the body, which is the neurotransmitter thought to be closely involved with the regulation of cognitive processes. Aniracetam is partially cholinergic in its mechanism of action, as it potentiates the action of nicotinic acetylcholine receptors.[3] When aniracetam is paired with a choline source, the increase in acetylcholine will theoretically potentiate the cholinergic effects of aniracetam.

Phosphatidylserine is a naturally-occurring fatty acid derivative that helps comprise cell membranes. In 2003, the Food and Drug Administration (FDA) authorized sellers of phosphatidylserine to label their products with the claim that “consumption of phosphatidylserine may reduce the risk of dementia and cognitive dysfunction in the elderly.” [4] Various studies have indeed confirmed that supplementation of phosphatidylserine can improve cognition[5], memory[6], and processing speed[7], among other factors. Phosphatidylserine also has the potential to increase levels of acetylcholine in the brain, an effect that would work synergistically with aniracetam’s cholinergic mechanisms. [8]

Pycnogenol is a patented extract of pine bark, containing a number of antioxidant flavonoids known as procyanidins. Pycnogenol’s most notable effects include its ability to increase blood flow[9], while also improving attention and cognition.[10] Pycnogenol’s main mechanism seems to be its ability to increase concentrations of nitric oxide (NO). It does this by preventing NO from oxidizing while also inducing the Nitric Oxide Synthase (NOS) enzyme, which catalyzes the production of NO.[11]

My Experience

Note: When dealing with anecdotal experiences, it is difficult to completely rule out the placebo effect as the cause of certain perceived changes in cognition and mood. This is simply my own experience, and it is likely that every individual’s experience with these nootropics will vary. These are simply the effects I perceived.
Previous to this experience, I had taken aniracetam on a few occasions with modest success, taking it with a choline source.

My dosing regimen of Nexus consisted of taking 2 capsules in the morning after I woke up. I took another dose in the afternoon or evening if I was working on tasks that benefit from boosts in cognition (i.e. writing, analysis). During this time period, I was also taking fish oil, bacopa monnieri, and centrophenoxine, which I have been taking regularly for at least a month. I was thus familiar with their effects and would be able to perceive any changes brought on by adding this stack. I took Nexus regularly for about one month.
One of the most marked improvements I noticed was a modest reduction in anxiety that set in about an hour after taking Nexus. I am typically a fairly anxious person, both in general and in social situations. I felt more able to focus on important tasks, rather than focusing on anxious thoughts I was having. I also felt a noticeable clear-headedness and ability to think straight.

There was also a subtle improvement in being able to pick up on new concepts more easily. During college courses, I felt very engaged in the materials being presented, even in the classes, I do not normally find very interesting. I also found it easier to contribute to the discussion.
Taking another dose before working on writing essays and papers seemed to help a great deal with my cognition. Aniracetam has anecdotally been touted to improve holistic and collective thinking, and that seemed to be the case in my experience. It was much easier to weave different concepts and themes together in a way that presented a coherent bigger picture.

Again, when it comes to nootropics, it can be difficult to differentiate legitimate effects from placebo. However, many of the effects I experienced were extreme enough that I am fairly convinced that they were effects of this stack.


Everyone is likely to react differently to a nootropic like aniracetam. There are some people I know who experience little to no effect from taking it. For others, the effects seem to be almost life-changing. However, I do feel like the additional ingredients in Nexus’s blend contribute a good deal to its effects. It seemed to have greater effects than just aniracetam alone.

This being said I can definitely recommend trying Nexus out. It is a good stack for those who are fairly new to nootropics and aren’t sure how to formulate their own stacks, but for the expert nootropic user, it is definitely overpriced. That said, I would definitely like to use it again in the future.

Axon Labs' NEXUS
Reviewer 7.1
I would recommend this stack to anyone who is into experimenting with nootropics. It gave me a clear cognitive boost while simultaneously reducing anxiety.

References   [ + ]

L-Theanine Nootropics Stacks

Caffeine & L-Theanine: The Beginner’s Nootropic Stack

Caffeine: it’s everywhere. Apart from alcohol, no other substance is as widely used and accepted by society as caffeine. From traditional sources like tea and coffee to energy drinks, to supplements found in the supermarket, caffeine is affordable, convenient, and effective. It has permeated the lives of the majority of people in the world – 90% of the world’s population consume some form of caffeine on a daily basis.[1]

Caffeine, mainly in its beverage form of coffee, is used en masse by society, so much so that it is hardly even thought of as a drug. It is so casually consumed by most people that not much thought is given to how it works, how it can be beneficial, and how it can be potentially harmful.

It is well known that caffeine can carry with it several unpleasant side effects. Certain individuals can be more sensitive to caffeine than others, and some are more susceptible than others to these side effects. The most commonly reported side effects of caffeine include increased blood pressure [2], anxiety, jitters, and insomnia. [3] Luckily, many caffeine users have found a potential way in which these uncomfortable effects can be prevented. The answer comes in the form of one non-essential amino acid: theanine.


Theanine chemical formulaTheanine is a naturally-occurring amino acid found in various plants, mainly certain types of green tea. Only the L (“levo”, left)-enantiomer of theanine has been extensively researched for its effects in humans, and references to “theanine” typically imply only L-theanine.

The compound itself was first isolated from tea leaves in 1950 and has since gained widespread popularity as a dietary supplement. In the United States, it has been approved for over-the-counter use. Response to L-theanine in Europe has not been as favorable. The European Food Safety Authority (EFSA) has objected to claims of L-theanine being beneficial to cognition and stress, and it is not sold under any kind of health claims.

Perhaps the most alluring aspect of L-theanine comes with its ability to promote relaxation without being sedating. This property has led to its widespread use alongside caffeine. Potentially, the relaxing effects of L-theanine “take the edge off” of caffeine use by mitigating the jitters that come with caffeine, all while working alongside caffeine to improve cognition and alertness.[4] It has also been found to reduce blood pressure, which is especially helpful for those who experience high blood pressure from caffeine use. [5]

After ingestion, L-theanine crosses the blood-brain barrier (BBB) with relative ease.[6] Its effects set it within an hour from ingestion, and effects last for about 5 to 6 hours after administration. [7]

Theanine does not have a significant impact on increasing the levels of monoamines (i.e. serotonin) or catecholamines (i.e. norepinephrine) in the bloodstream. [8]

Because theanine is structurally similar to the neurotransmitters glutamate and glutamine, it competes with them at their transporters, which can reduce synaptic levels of glutamate, a dangerous neurotransmitter that causes neurotoxicity in high levels. [9]

Additionally, administration of L-theanine has been found to increase GABA levels in the cerebrum by nearly 20%.[10] GABA is an inhibitory neurotransmitter, and this is largely thought to be a major contributor to Theanine’s anxiolytic and relaxing effects. However, research has not yet provided a conclusive answer to L-theanine’s exact mechanism of action.


While L-theanine is a respectable anxiolytic and cognitive enhancer in its own right, most users find it most effective when paired with caffeine, as mentioned above. To understand the power of stacking caffeine with L-theanine, it’s also important to know the way in which caffeine operates.


Caffeine’s stimulant properties come mainly from its action as an adenosine receptor antagonist. When adenosine receptors are activated by adenosine, it causes drowsiness in the individual. Adenosine accumulates naturally in neuronal synapses, and lower levels of adenosine translate to feelings of alertness and wakefulness. Because caffeine binds to adenosine receptors competitively, it inhibits adenosine from binding to the adenosine receptors, which in turn makes the body feels more awake.[11] Of course, when caffeine is eliminated from the system, adenosine is once again free to bind to its natural receptors, returning the body to feelings of drowsiness.

Even though caffeine’s main effects are due to its adenosinergic mechanism, caffeine consumption also has an impact on other neurotransmitters. Caffeine (particularly in high doses) reduces the conversion of tryptophan to serotonin and this may exacerbate depression, especially if caffeine use is suddenly stopped.[12] Therefore, 5-HTP, a serotonin precursor, can be used to counteract Caffeine withdrawal symptoms.

Stacking Caffeine & L-Theanine

Theanine and Caffeine have powerful synergistic effectsThe simultaneous use of caffeine and L-theanine appears to be the most common combination or “stack” of substances utilized by users of nootropics. Because both caffeine and L-theanine are cheap, well-studied, and generally accessible, it is a good starting point for those who are just getting into nootropics and cognitive enhancement. If you already use caffeine in any form, it wouldn’t hurt to see how L-theanine works for you.

Common combinations of caffeine and L-theanine are a 1:1, 1:2, 2:1, or 2:3 ratio of caffeine to theanine. The effectiveness of each ratio varies widely among individuals, so some trial and error might be necessary to find the right amounts. If you do not use caffeine regularly, it would be wise to start with a 1:2 ratio – that is, 100 mg of caffeine with 200 mg of theanine – and adjust from there. There is no “correct” way to stack the two, and it is mainly a matter of preference and personal brain chemistry.

Multiple studies using about 100 mg of L-theanine alongside 50 mg of caffeine demonstrated that the combination of the two had a fairly significant impact on cognition, even more so than either substance by itself. [13] [14] L-theanine use in combination with caffeine also helps users remain focused on single tasks without being distracted by outer stimuli. [15]


Many nootropics are most effective when combined with other complementary substances. Researching different nootropics and their effects and benefits can be both fun and rewarding. However, sometimes the amount of information available makes it difficult to find a starting point. A combination of caffeine and L-theanine is the perfect starting point for anyone who is interested in nootropic supplementation and increasing their cognition. Because both compounds are well-studied both separately and in combination, it is a safe starting point for introducing people into the world of cognitive enhancement.

For those of you who don’t like messing up with powders (or just like the convenience of pills), try premixed Caffeine and Theanine caps

References   [ + ]