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CILTEP By Natural Stacks: Review & Buyer’s Guide

By on August 7, 2018 in Focus Supplements with 0 Comments

CILTEP By Natural Stacks Supplement Review

Supplements with purported mind-sharpening properties represent the fastest growing segment of a multi-billion dollar nutraceutical industry. All over the world companies have piqued the interest of consumers searching for a mental edge at work, at school, or in day-to-day life.

Combating fatigue, improving concentration, and searching for a lift in motivation, or even mood, are some of the most common goals of these individuals.

In this review, we tackle the important questions: what does the available scientific evidence have to say about this nootropic? Are supplements like CILTEP worth the investment at all? And what options for cognitive optimization available today represent the best value for money?

After first examining Natural Stacks (the manufacturer) and their philosophy toward formulating their product, we will move into a systematic analysis of each ingredient in the blend. However, with a nootropic ‘stack’ like CILTEP, it is also important to consider the product as a whole — is it more or less than the sum of its parts?

Multiple online communities have sprung up dedicated to crafting situationally appropriate nootropic stacks but in practice, great nuance is needed to understand the interactions and synergies at work that combine to create an overall experience, good or bad.

This review takes a scientific, fact-based approach but we will also draw occasionally on field-tested reports from users with first-hand experience using the product on a regular basis.

Natural Stacks and their Approach To Formulation / Customer Service

Scientist handles a supplement capsule

Natural Stacks are a Seattle based company and CILTEP is manufactured in the USA. They retail a range of other supplements and, although their primary focus appears to be mental performance (mood/focus/sleep), they also offer a range of vitamins, as well as whey protein and creatine.

The company philosophy appears to place a heavy emphasis on formulating natural products. A common marketing tactic, this so-called ‘appeal to nature‘ is of limited meaning beyond its use as a sales ploy. Nevertheless, some customers will be pleased to know that CILTEP is gluten-free, non-GMO, and vegan-friendly.

A highly refreshing element of the Natural Stacks approach is their transparency with regard to the sourcing and purity of their ingredients. Independent third parties are employed to conduct regular batch tests and the results are posted frequently.

The exact contents of the blend are openly revealed and the suppliers from which they source their raw ingredients are also listed. In an industry where guarded behavior is the norm, Natural Stacks deserve credit for removing any veil of secrecy.

The instructions for use for CILTEP contain a convenient upsell for another product in the range: Smart Caffeine. This supplement is a simple blend of ‘natural’ caffeine and the amino acid L-Theanine (from green tea). This extra stimulation allegedly helps to extend and optimize the effects of CILTEP. L-Theanine is a worthwhile addition to the caffeine blend if only for its capacity to promote relaxation (1).

Before we launch into a detailed analysis of CILTEP’s ingredients it’s worth briefly touching on the company’s approach to customer service. For the purposes of this review, we will ignore customer reviews posted directly to the retailer’s website because of the clear potential for bias.

Natural Stacks retail all their products on Amazon on an FBA basis (fulfilled by Amazon). This virtually guarantees hassle-free delivery because Amazon themselves dispatch orders from their own warehouses. The company also offers a 30-day money-back guarantee on all purchases made through Amazon or through their own website.

Reverse-Engineering The Product

CILTEP ingredients label

Included in the CILTEP ‘recipe’ is:

  • Artichoke Extract
  • Forskolin
  • Acetyl-L-Carnitine
  • L-Phenylalanine
  • Vitamin B6

We will explore the overall scientific evidence available for each ingredient before looking more closely at the blend as a whole.

Artichoke Extract

Artichoke extract capsules

CILTEP contains 900mg of an artichoke extract. Along with forskolin, this extract is central to the guiding principle of the supplement and its patented methodology.

In short, synapses in your brain act as junctions. Through these junctions, neurons are able to send signals to each other and indeed other cells (including those in muscles).

In neuroscience, long-term potentiation (LTP) refers to the 20th-century discovery that activity or stimulus in the brain can increase or decrease the effectiveness of these synapses. Stronger synapses improve signaling between neurons. Long-term depression (LTD), on the other hand, is a state of reduced effectiveness of the brain’s synapses.

Luteolin is a flavonoid contained naturally in artichoke and other vegetables, including celery and broccoli. In theory, by inhibiting an enzyme responsible for the breakdown of the molecule cAMP in the brain, luteolin supports long-term potentiation.

Artichoke extract has been shown to inhibit the activity of the enzyme responsible for breaking down cAMP molecules (2).

Higher levels of cAMP within the brain are associated with improved cognition and memory as well as other markers of brain functioning of interest to the nootropic community (3,4,5).


  • CILTEP is the first nootropic supplement to specifically target the cAMP pathway as a means of improving cognition.
  • Artichoke extract is combined with forskolin (see below) to increase the potency of the supplement in increasing cellular cAMP levels.
  • A strong body of research highlights the role of cAMP in long-term potentiation and subsequent cognitive benefits.


  • It is still too early to say whether orally ingested luteolin (from artichoke extract) at the dosage offered by CILTEP is actually effective at significantly increasing cAMP levels in the brain.
  • We can’t say for sure whether the cognitive benefits experienced by some users of CILTEP are truly a result of increased cAMP levels, or whether another mechanism is responsible.


Forskolin is perhaps more popularly known as the herb used by many dieters to help induce fat loss. Commonly employed in traditional medicine, forskolin is also thought to possess cognitive enhancing properties.

Unlike artichoke extract, which inhibits the enzyme responsible for the breakdown of cAMP molecules, forskolin appears to act on a separate enzyme — adenylyl cyclase — which in turn increases cAMP levels within cells (6).

The two-fold action of artichoke extract and forskolin in promoting cAMP and slowing its degradation is hypothesized to support long-term potentiation (the strengthening of synapses).

CILTEP contains 20mg of Coleus forskohlii root extract. This provides a total of 4mg of the active ingredient forskolin.


  • Forskolin offers a second and separate route when combined with artichoke extract to increased levels of cAMP molecules within cells.
  • This two-pronged approach may be responsible for improved cognition and memory.


  • It is difficult to gauge the extent to which the forskolin dosage in CILTEP is capable of elevating cAMP levels in the brain. Forskolin increased cAMP levels by a third in rat brains but the dosage and method of delivery (injection) were different from what is offered by an oral supplement (7).


Acetyl-L-Carnitine (ALCAR) is the form of L-Carnitine most commonly utilized in cognitive enhancers and nootropic supplements. The standard dosage is 500mg-2,500mg and therefore the quantity of 750mg present in CILTEP is within the therapeutic range.

L-Carnitine is made in the body and is also obtained from dietary sources including meat and dairy products. It has an important role in energy metabolism.

When compared to placebo (dummy pill), ALCAR supplementation appears to boost cognition in patients with mild cognitive impairment and mild Alzheimer’s disease. Measured by both psychometric testing and clinical scales, these improvements were seen after 3 months of supplementation and continued to increase over time (8).

In a study of 13 boys with ADHD, most ‘responded’ to L-Carnitine dosed at 4,000mg/day and these improvements included significantly lowered aggression and increased attention (9).

ALCAR decreased mental fatigue and improved concentration in participants (chronic fatigue syndrome (CFS) patients) in a 24-week trial (10). The dosage used in the trial was 2,000mg/day.


  • ALCAR supplementation is largely safe and trials conducted to date have revealed very few side effects.
  • Trials in specific populations (ADHD, CFS, cognitive impairment) have yielded highly positive results in various areas of cognition.
  • L-Carnitine exhibits a protective effect on neurons. It appears to offset oxidative stress while helping maintain healthy levels of the chemical ATP in the brain (11). ATP depletion has been linked to Alzheimer’s disease (12).


  • Cognitive benefits in trials to date have mostly been proven in specific population groups, including those deficient in carnitine and the elderly (13,14). These results offer great promise but it is clear that more research is needed. In particular, we need to see more trials involving young and otherwise healthy adults.


Phenylalanine is an amino acid. L-Phenylalanine can be contrasted with DL-Phenylalanine (another common nootropic ingredient) in that the latter combines L-Phenylalanine with a synthetic version of the amino acid produced in labs.

The decision by Natural Stacks to opt for L-Phenylalanine is most likely one made in line with their policy of selecting natural ingredients. Nevertheless, both forms are safe for human consumption.

Phenylalanine is a precursor for tyrosine as well as the neurotransmitters dopamine and (nor)epinephrine.

Dopamine and norepinephrine play an important role in mood regulation and various other cognitive processes. In fact, these two neurotransmitters are the target of several anti-depressant drugs (including bupropion, which is marketed as Wellbutrin).

While recent research is lacking, a couple of small, older studies have established a promising link between DL-Phenylalanine and the alleviation of depression. One trial involving patients with treatment-resistant depression produced improvements in many within a short timespan (15).

Another study with 20 patients found reduced levels of depressed mood and anxiety in 12 patients, with a further 4 showing “mild-to-moderate” responses (16).

Meanwhile, L-Tyrosine (to which phenylalanine is a precursor) has stress-reducing and cognitive-enhancing properties. In a trial involving military personnel, a 100mg/kg dosage was associated with significant improvements in mood and cognitive function when subjects were exposed to cold and altitude. No changes in blood pressure or heart rate were detected between the groups receiving L-Tyrosine and a placebo (17).

Tyrosine also appears to preserve cognitive performance in states of sleep deprivation (18).

Vitamin B6

Vitamin B6 Dietary Sources

Vitamin B6 is one of 8 essential water-soluble B-vitamins. Although Vitamin B6 is present in foods such as meat, beans, and nuts, cognition can be negatively affected by the deficiency.

Although deficiency is considered to be relatively rare in the United States, there are some important caveats of which to take note. “Normal” ranges as defined by labs can be wide, leading to some individuals with a mild (yet still sub-optimal) deficiency being classified as having healthy levels of the vitamin.

Deficiency is also much more common in certain “at risk” groups. These include:

  • Women of child-bearing age, in particular, those using oral contraceptives
  • African-American men
  • Male smokers
  • People aged over 65

Vitamin B6 is a necessary enzyme in the brain’s synthesis of a myriad of neurotransmitters: dopamine, norepinephrine, serotonin, melatonin, and GABA.

Research has demonstrated that even mild B6 deficiencies can interfere markedly with optimal neurological functioning (19).

Exploring Synergies / Limitations

Artichoke + Forskolin

The patented and novel approach to cognitive enhancement used by Natural Stacks is largely premised on the combination of these two natural ingredients.

The supplement acts on cAMP levels in the brain through two separate mechanisms: luteolin (in artichoke extract) inhibits the activity of an enzyme that breaks down cAMP molecules, and forskolin activates an enzyme which increases levels of cAMP within cells.

By simultaneously boosting cAMP levels and inhibiting the breakdown of the molecule, CILTEP aims to improve long-term memory and alertness.


Some members of the nootropic community have taken aim at Natural Stacks in an effort to debunk claims regarding long-term potentiation arising from increased cAMP.

For instance, concerns have been expressed regarding the actual bioavailability of luteolin when absorbed (20).

Nevertheless, many positive anecdotes have arisen from members of nootropic and biohacking communities.

What is absolutely clear at this stage is there remains a relative paucity of high-quality research regarding so-called Chemically-Induced Long-Term Potentiation (AKA CILTEP).

cAMP is an exciting and promising target for nootropics and artichoke extract and forskolin are both areas of active ongoing research.

CILTEP vs Alpha Brain

 CILTEPAlpha Brain
Manufacturer:Natural StacksOnnit Labs, Inc.
Monthly Price (when taken as recommended):$42.95 (2 capsules per day)$50.90
Serving size:1-3 capsules per day.2 capsules per day.
Advantages:Exciting and novel approach to cognitive enhancement. Useful for people who've failed to see results from other mainstream manufacturers who follow the same formulas as each other.Offers good value for money. Contains numerous adaptogens, amino acids, and nootropics.
Disadvantages:User reports suggest a hit-and-miss success rate with CILTEP. Some consumers report great results while others fail to see any meaningful benefit.Lacks the punch of formulations with more ingredients.

Is it worth the money?

Verdict: Yes, it’s definitely worth a try.

At a relatively low price point compared to rivals such as Mind Lab Pro and Qualia, CILTEP is a good choice for introductory and serious nootropic consumers alike. Natural Stacks’ 30-day money back guarantee offers added peace of mind.

The cAMP pathway of cognitive enhancement is a novel and highly creative approach, and deserves serious examination, even as large-scale scientific evidence struggles to keep up with innovation in this field.

Other ingredients like Acetyl-L-Carnitine and L-Phenylalanine may offer serious benefits to mood, stress-resistance, and alertness.

How to buy

CILTEP is available on the website of Natural Stacks as either a one-off order or on a subscription delivery service. Discounts over the single-bottle price are available on these subscriptions and also on multi-bottle orders.

In addition, CILTEP is retailed on Amazon and is eligible for rapid, Amazon Prime delivery. As of writing, the single-bottle price is $2 lower on Amazon than on the Natural Stacks website.

How to take

Take 1-3 capsules first thing in the morning on an empty stomach. You can experiment with dosage to find the optimal amount for your needs within this range.

The manufacturer also recommends trying CILTEP with moderate doses of caffeine to further enhance focus and alertness. This can be obtained through tea or coffee, or the Smart Caffeine product retailed by Natural Stacks.

Smart Caffeine is a simple combination of caffeine and L-Theanine, both of which are present in green tea, so we recommend saving some money by simply sipping a refreshing cup instead of parting with additional money for supplements.

To maintain sensitivity to the effects of the product, it is also advisable to follow a weekly cycle of approximately 5 days on, 2 days off. The 2 days off needn’t necessarily be consecutive days of the week. However, many users opt to take weekends off to save their regular dosage for work days.

Minimizing side effects

Side effects appear to be minimal. If you do experience any stomach discomfort or nausea when taking CILTEP, try consuming the capsules with food instead.

Conclusion — Does it work?

This review has placed heavy emphasis on a detailed scientific examination of each ingredient in CILTEP.

Crucially, unlike most reviewers, we largely eliminate first-hand user reports because these are notoriously prone to bias. We hope that by grounding our review in impartial facts you’ll get the fairest view of the advantages and disadvantages of each supplement.

Here is another look at the pros and cons of CILTEP:


  • Targeting cAMP elevation in the brain is an exciting and highly promising approach to cognitive enhancement. As noted earlier, increased cAMP within brain cells is associated with improved cognition and memory (3,4,5).
  • When reading nootropic labels you’ll often find the differences between leading brands to be virtually indistinguishable. The patented combination on offer in CILTEP offers a new avenue for nootropic users who’ve failed to see results with other brands.
  • The pricing of CILTEP is reasonable and lower than many rival brands including Qualia, Alpha Brain, and Mind Lab Pro.


  • More research is needed before we truly understand the role of artichoke extract and forskolin in boosting cAMP levels. Study design should focus on large-scale human trials.

More opinions / Further viewing

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About the Author

About the Author: Tom Andrews BSc is the editor of He devotes his time to psychology and mental health research and also enjoys climbing, hiking, and team sports. Tom is a contributor to several other highly regarded health magazines and blogs.


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