Performance Lab Stim Review

Overall Rating



Performance Lab® Stim is smarter and cleaner. With Natural Caffeine 50 mg + Suntheanine® 100 mg, it delivers greater dosing precision, fewer side effects and superior performance-tuned stimulation.

Caffeine is a leading natural performance enhancer. However, while it has its perks when taken correctly, too much of it can lead to jitters, crashes, and anxiety concerns.

So, to enjoy the benefits of this nootropic, individuals should determine their optimal caffeine dose. Unfortunately, this can be hard for most people who rely on caffeine every day to perform optimally.

But what if we told you that it doesn’t have to be that way? Thanks to Opti Nutra’s Performance Lab Stim, you don’t have to worry about managing your caffeine intake.

This supplement claims to deliver greater dosing precision of caffeine with fewer side effects for a cleaner, calmer stimulation. But can Opti Nutra really substantiate this claim? And what else can this supplement do? Read our review to find out.

What is Performance Lab Stim?

stim NEW

Simply put, it’s a dietary supplement that claims to deliver balanced, optimized and productive caffeine stimulation. Apparently, it contains natural caffeine in the right dosage to help reduce some of the negative effects associated with caffeine overstimulation.

What’s more? This supplement claims to help restore caffeine-depleted chemicals for superior performance.

So, who makes this supplement? Well, the stack is made by Opti Nutra which is based in the U.K. This company is known to produce some of the best nootropics in the market, including their flagship product, Mind Lab Pro.

But did you know that this supplement is the very first product from Opti Nutra to contain caffeine or stimulants? Yeah, that’s true! Over the years, the manufacturer has built a brand around 100% natural non-stimulant products.

They designed this product to help improve caffeine’s performance-enhancing effects without having to worry about overstimulation. But does it even work? If yes, then how?

How Does It Work?

This stimulant works by enhancing your overall performance in a healthier way. It does this by combining natural caffeine with vitamins and essential amino acids.

According to the manufacturer, the supplement has been shown to raise Alpha brainwaves and replenish depleted brain chemicals. This helps in balancing caffeine energy with clarity, relaxation, and creativity.

Additionally, it may help promote:

  • Alertness
  • Revitalized performance especially when multitasking
  • Reduction in stress and fatigue
  • Superior athletic and thermogenic performance

Ingredients List

stim ingredients

This product appears to have a pretty clean and clever list of ingredients. It combines caffeine with an innovative dual-stack formula to deliver cleaner stimulation. That said, let’s take a closer look at each of its ingredients to understand better how exactly it works.

1. NutriGenesis Caffeine Balance B-Complex

According to a 2014 study published on ResearchGate, researchers linked over-consumption of caffeine with depletion of water-soluble vitamins. These include vitamins like B12, B6, Riboflavin (B2), and Folate (B9).

This is because caffeine has a mild diuretic effect that leads to increased urination. Consequently, this leads to the vitamins being depleted as a result of fluid loss.

And since these B-vitamins have been shown to perform essential functions within the body, Performance Lab Stim made sure to include them. What’s more, the vitamins have been complexed with cofactors to ensure better absorption.

2. Natural Caffeine

Derived from Coffea robusta seeds, the caffeine in this supplement comes from natural sources. So, it’s not anhydrous caffeine.

Being a popular stimulant around the world, caffeine is known to support several key aspects of performance. However, too much of it can cause overstimulation which paradoxically worsens performance.

As such, individuals need to take an optimal dose. Stim from Opti-Nutra contains 50 mg of caffeine per serving which we think it’s a relatively low dose. This is because some products contain up to 300 mg of caffeine.

However, the manufacturer claims that the dosage is enough to supply equivalent caffeine between a cup of green tea and coffee. And with this approach, it may help you identify and even manage your optimal dose.

3. Suntheanine L-Theanine, 100 mg

L-Theanine is an amino acid that is naturally found in green tea. This ingredient has been shown to enhance alpha brain waves which are associated with various cognitive benefits. Some of them include reduced anxiety, wakeful relaxation, enhanced creativity, and mood balanced.

When taken with caffeine, it may help reduce the side effects of caffeine like anxiety, jitters, headaches, and nausea. Simply put, this ingredient enhances caffeine to promote cleaner and calmer stimulation for peak performance.  

In a 2018 study conducted in the U.K, L-Theanine and caffeine combination was shown to improve the performance of cognitively demanding tasks. It is worth noting that this study compared 50 mg caffeine and 100 mg L-theanine.

5. Ajipure L-Tyrosine, 250 mg

Similar to L-Theanine, L-Tyrosine is an amino acid that is directly involved in the production of neurotransmitters like dopamine and epinephrine. These neurotransmitters are part of a family of hormones called catecholamines.  

And as it turns out, caffeine stimulation may lead to low levels of the aforementioned neurotransmitters. This may eventually lead to mood imbalance, long-range exhaustion, attention problems, and short-term crashing.

So, according to Opti Nutra, the addition of L-Tyrosine in this formula helps restore the caffeine-depleted neurotransmitters. This results in better working memory, reduced fatigue, quicker thinking, and enhanced multitasking performance.

Try This Nootropic Supplement!

How to Take It

The recommended dosage of Performance Lab Stim is one capsule per day. According to the official website, this serving size is effective for most individuals.

However, people with higher optimal caffeine dose or greater tolerance can take up to five NutriCaps per day. This is equivalent to 250 mg caffeine.

What’s more? You can choose to take the supplement solo or stack it with other Performance Lab formulas to enjoy a clean, balanced stimulation.

Any Potential Side Effects?

Like most Opti Nutra’s products, Stim is designed to be safe, especially for long-term and daily use. This is because it contains minimal caffeine dose which is all-natural. Besides, it incorporates ingredients that are designed to minimize the common side effects associated with caffeine.

On top of that, the product is free of banned substances, GMOs, gluten, allergen, soy, and synthetic additives. As if that’s not enough, it is GMP certified and the capsules are vegan-friendly as well as 100% plant-based.

However, if you happen to take more than 5 capsules in a day, then you may experience mild side effects. These include upset stomach, insomnia, nausea, anxiety, and jitteriness. Therefore, it is advisable that you stick to 50 mg caffeine and gradually increase the dosage only if necessary.

Where to Buy, Pricing, Shipping, & Return Policy

Currently, you can only buy Performance Lab Stim at Opti Nutra’s official website. The manufacturer offers this product in three packages including a month supply, two month supply, and three month supply.

Generally, a month supply containing just 30 NutriCaps costs $39. A two month supply, on the other hand, includes two bottles with both going for $78. Therefore, it’s clear that this product does not really come cheap.

However, if you choose a three month supply, you will get three bottles of Stim and an extra one for free. This supply will cost you $117 only. So, it is evident that you get to save more money if you opt for the three month supply package.

As far as shipping and handling are concerned, it is free for the three month supply package. However, for the other two packages, shipping is not free.

But here is the best part; Opti Nutra offers you a 30-day satisfaction guarantee. This means you can try this supplement for 30 days and if you don’t see results, you’ll get a refund. You can return the empty bottle and any other unused bottles. This promise only covers up to a maximum of three products per order.

Who Should take these Pills?

Stim is a natural and safe way to stimulate both body and mind. Therefore, anyone looking to enhance their overall performance and life vitality can take this dietary supplement. These include gym freaks, students, professionals alike, and even nootropic geeks.

And as a clean source of caffeinated energy, this product may also work well for all types of competition including mental and physical.

Additionally, Stim could potentially benefit anyone seeking to lower their alternative caffeine intake. Also, individuals who don’t habitually use caffeine may experience superior results.


  • Contains a modest amount of natural caffeine
  • The manufacturer has fully disclosed the amount of each ingredient
  • Free from synthetic flavors, colors, and preservatives
  • Delivers cleaner stimulation with fewer side effects
  • Can be taken by anyone looking to enhance their overall performance
  • Safe for daily and long-term use
  • Made from patented ingredients that counterbalances caffeine demands
  • Inexpensive if you buy in bulk
  • Can be safely stacked with other Performance Lab’s products
  • Offers empty bottle, 30-days money-back guarantee


  • You may need to take two servings or more for maximum benefits
  • At $39 per bottle of 30 capsules, it doesn’t come cheap, especially if you’ve to take more servings
  • You can only purchase the supplement on their website. It’s not available on sites like Amazon.

Final Thoughts

Overall, there aren’t as many benefits to taking caffeine pills. However, if you choose to take them with the kind of formula Performance Lab Stim provides, then it can make the difference. This is because this product appears to deliver clean energy on demand, balanced mood, less anxiety, and enhanced creativity.