Can You Get More Out Of Caffeine? Reviewing Smart Caffeine By Natural Stacks

by Alexandra R

In the world of nootropics, it increasingly seems like complexity is king: new, proprietary blends regularly come onto the market, and while many are very effective and rank among our favorite supplements, it can be refreshing to find a straightforward, simple formula. Smart Caffeine by Natural Stacks (click for best price) is almost as simple as they get, and its caffeine and l-theanine pairing (that’s basically it) have been gaining popularity on the web.

While we’re familiar with both of Smart Caffeine’s active ingredients, the proof is in the testing. Read on to find if this simple stack was enough to give the BrainWiz testers a mental boost.

Smart Caffeine By Natural Stacks Label

Smart Caffeine By Natural Stacks Label & Ingredients

The Ingredients

Natural Caffeine Anhydrous from Coffee Beans – 100 mg

The world’s most popular stimulant, caffeine actually works by preventing adenosine from acting on adenosine receptors in the brain. This inhibitory mechanism reduces feelings of drowsiness and sedation. Caffeine is a well-researched, well-known, and common ingredient in many brain supplements, and a big reason coffee is one of the world’s most in-demand commodities. Research suggests caffeine and l-theanine pairings boost alertness and cognitive performance.

L-Theanine – 200 mg

An amino acid that’s becoming an increasingly common ingredient in nootropics, l-theanine promotes relaxation without being a sedative, and research suggests it also helps the brain deal better with stress. Often paired with caffeine, l-theanine’s effects appear complementary to the world’s most popular stimulant. It may also increase brain activity and memory. L-theanine is commonly found in green tea, and a standard cup contains around 20 mg (so one pill of Smart Caffeine contains a high dosage relative to standard tea consumption).

Other Ingredients: Vegetable capsule, cellulose, vegetable stearate, silica.

Usage Guidelines

Suggested Use: take a serving of 1-2 capsules whenever focused energy is desired. Avoid use in the evening. Total daily dosage should not exceed 6 capsules.

What Our Testers Say

“I had to be careful with Smart Caffeine, because while 100 mg of caffeine isn’t much more than a cup of coffee (and less than some), it’s not something I’d want to take in addition to my normal morning coffee. But when the afternoon rolled around and I couldn’t step out of the office for another cup of coffee, I thought this was pretty handy. I didn’t feel any jitters at all, even when I took it on an empty stomach (though not something I’d recommend doing regularly).”

“As BrainWiz’s resident non-coffee fanatic, I wasn’t sure what to expect here; most supplements I’ve tried with stimulants, including coffee, make me at least a little jittery, so I normally opt for adaptogens like Rhodiola rosea. But Smart Caffeine worked for me about how the website said it would: reduced fatigue, no antsy feeling, and it wore off after a few hours a lot smoother than caffeine on its own ever does for me. I’m not sure I want to make caffeine a daily thing (I’m probably along there), but I’ll keep this one handy.”

“I thought this supplement was relatively mild. It’s caffeine with a cool l-theanine pairing that helps you stay relaxed and reduces the chance of a crash. That’s cool, but it’s not going to replace my coffee.”

“It’s a lot more accessible and quicker than a cup of coffee, which is why I had to be careful to stick to 1 or 2 capsules, tops. I’m not sure what else I’d stack this with, if anything, but I liked it and will keep it in my rotation.”

Smart Caffeine
4.4 / 5 Score
  • Easy to take
  • Fast acting
  • Simple formula
  • No crash
  • Cons
  • Caffeine heavy
  • Summary
    Smart Caffeine from Natural Stacks is one of the most straightforward, simple beginner stacks we've ever tested. It's the widely popular caffeine + l-theanine pairing in clear dosage, giving an energy boost with a reduced chance of crash or jitters.
    Beginner Friendly

    BrainWiz Tips

    • Take with breakfast to ease absorption, especially if you’re sensitive to caffeine.
    • Avoid taking with other stimulants or supplements containing stimulants like coffee or guarana.
    • Our testers who had the best results with Smart Caffeine took one or two capsules first thing in the morning and another one during the early afternoon to get through a post-lunch slump.
    • Cycle a few days on with a few days off to reduce the body’s natural inclination to build caffeine tolerance.
    • It’s always a good idea to talk to your doctor or a medical professional before starting a new supplement regimen. Though common, caffeine is still a stimulant, so start slowly if you’re sensitive to such substances.

    Supplement Summary

    If you’re not a coffee drinker, Smart Caffeine is an excellent option to get an energy and focus boost without the same level of jitters that comes along with many stimulatory supplements. None of our testers felt a significant crash as the supplement’s effects wore off. We also appreciate how transparent Natural Stacks is with the amounts of each ingredient in Smart Caffeine.

    If you are a coffee drinker, Smart Caffeine may not be the best option to pair with your morning cup, but we enjoyed it for an incredibly convenient early or mid-afternoon energy boost.

    DISCLAIMER: We are not doctors. The opinions on this website are not to be taken as medical advice. None of these opinions have been reviewed by the FDA. Consult your doctor before taking any supplements. We receive free products to review and participate in affiliate programs, where we are compensated for items purchased through links from our site (at no cost to the buyer). See our disclosure page for our list of comped products and affiliate programs. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to

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