I've been taking Natural Stacks Smart Caffeine for a little over a month, and the stack is great! Good smooth energy and focus with no crash, and you can take it later on during the day and still be able to sleep well at night. Great supplement. Thank you Natural Stacks!

2019-04-28

The smart caffeine is great. I was using energy drinks that had all sort of preservatives and artificial ingredients. Now I am off of those and enjoying the focused energy I get from Natural Stacks Smart caffeine!

2020-11-15

Smart Caffeine is my favorite quick and easy pick me up! With just the right amount of caffeine, I can take this in the morning and in the afternoon without any crappy after affects; I never get jittery! It makes traveling easy too, no need to worry about finding the next $5 coffee, just pop one of these and be on your way!

2019-09-01

Smart caffeine gives me that boost of focused energy when I need it. After long hours of studying and you need to keep going to get your project submitted on time ... this comes highly recommended

2019-06-28

This is an a great supplement to add to natural stacks Ciltep stack! And once again, their products never cease to amaze me!!!! And the people behind it are awesome!!!!

2019-03-23

I have noticed an increase in alertness and memory since starting this a few months ago.

2026-02-03

Works great. You feel the energy from the caffine like you do from an energy drink but you don't get an jitters or heart beating to fast like you get from some drinks

2026-01-06

Consistent energy and focus gain every time. I take 1 of these with 3 Neurofuels for maximum productivity. No crash or jitters. Great prouct.

2025-11-20

Great supplement for traveling. I traveled to Ohio a lot and it’s a great pick me up early in the afternoon without feeling jittery.

2025-06-13

I was skeptical about how well this would work but I was pleasantly surprised! Well worth the purchase.

2025-05-12

I use Smart Caffeine almost everyday! It keeps me alert and focused throughout without any crash or jitters.

2024-11-18

It’s not overpowering but you can tell it’s working.

2024-09-17

It is a fantastic product. Sustained energy and focus without jitters or crash. Highly recommended!

2024-08-21

I use this supplement absolutely every day. I have appreciated this supplement for several years now. It goes with me everywhere I go. One a day first thing in the morning.

2024-07-16

I love is product and take it in the morning with my mushroom coffee.

2024-07-08

For once! A product that works as advertised! Truly, a smart version of caffeine👌

2024-06-12

I took it in the morning and while I didn't have jitters I couldn't fall asleep until after 4am

2024-06-05

I love this product. I've always wanted caffeine pills that were 3rd-party tested, and also pills that contain theanine, which does a GREAT job of keeping the jitters away while maintaining the alertness and focus you want. Highly recommend this for all folks wanting to get away from drinking coffee, or folks who want to try out caffeine pills.

2024-04-29

I'm very impressed with this product and is way better than energy drinks plus no crash later in the day. I would highly recommend it!

2024-04-23

it kept me focused and gave me that little boost you need in the mornings without the gitters.

2024-04-15