Granite Supplements ARC REACTOR Pre-Workout Review


  • Optimal dosage of L-Citrulline
  • Caffeine can raise energy levels
  • Beta-Alanine can enhance muscular endurance


  • Caffeine slightly over-dosed (increased risk of jitters)
  • Beta-Alanine also causes itchy & tingly skin
  • Missing key pre-workout ingredients (eg. Creatine Monohydrate)
  • Betaine can cause your breath & sweat to smell fishy

See Your Best Options In Our
Top 3 Pre-Workouts Page


About The Product

Arc Reactor is a pre-workout supplement made by Granite Supplements. It costs $48.99 for 20 serving containers, making it one of the most expensive pre-workouts we’ve reviewed.

From first glance, we’re happy to see that Granite Supplements has added an optimal 6,000mg dosage of L-Citrulline. We’ll also acknowledge that Beta-Alanine is able to enhance your muscular endurane, and we’re very happy that no ingredients are hidden in any proprietary blends.

However, the bad news is that Arc Reactor is missing some key pre-workout nutrients, such as Creatine Monohydrate.

Well expand on this as we analyze Arc Reactor’s nutrient profile in the next section. But first, we’ll tell you more about the company behind it.

Who are Granite Supplements 

We first saw this product through a Facebook advertisement, so we thought we’d click through and see what it’s all about.

Granite Supplements are a USA-based supplements company; from their website, we believe that their HQ is in California.

This company makes a variety of products, so we’re sure that we’ll get around to reviewing them another time. One thing we want to praise, is their great blog – it’s rare to see a company offering high-value content like Granite Supplements, so we were impressed by this.

Arc Reactor Ingredients Explained

Arc Reactor contains 10 main ingredients overall, which is a good number to have; we always prefer products containing under 10, as this gives the company a better chance of dosing nutrients better within budget.

As we mentioned, there’s a mix of ‘good’ and ‘bad’ things; L-Citrulline has been dosed optimally, while the slightly high dosage of Caffeine Anhydrous might cause those sensitive jittery side effects.

We’ll take you through each ingredient in Arc Reactor. By the end of this review, you’ll have a good idea of how safe and effective this pre-workout really is.


Here’s Everything You Need To Know:


We’re glad that Granite Supplements has added a big 6,000mg dosage of L-Citrulline in Arc Reactor.

What does it do? Well, L-Citrulline raises your nitric oxide levels, which increases your blood flow – enhancing your muscle pumps in the gym.

For us, improved muscle pumps are one of the main benefits of buying pre-workouts, so Granite Supplements has done well here. Great start.

But one tiny criticism we would make, is that we prefer Citrulline Malate; this is simply L-Citrulline bound with Malic Acid, which has shown to increase your ATP levels as well as enhance your muscle pumps, giving you improved strength and endurance too.

As we mentioned, though, Granite Supplements have done well by adding L-Citrulline anyway.

VasoDrive AP 

We’re not sure why Granite Supplements has added VasoDrive AP in alongside L-Citrulline; they’re both believed to offer the same benefit (enhanced muscle pumps), but L-Citrulline is much more reliable.

Why? Because we personally don’t believe that there’s any reliable clinical studies proving that VasoDrive AP works yet. Now, this might change in the future, so keep an eye on this section.

For now, it’s clear that L-Citrulline is much more reliable and effective, which isn’t a problem as there’s an optimal dosage in Arc Reactor.

Betaine Anhydrous 

Betaine Anhydrous is a fairly common addition to pre-workout supplements. So you might be worried to hear that it’s not shown to be very effective at improving your gym session.

But the bad news is that studies show Betaine Anhydrous to be capable of causing your breath and sweat to smell fishy; you can check out this clinical study for more details –

For this reason, we personally prefer to avoid Betaine Anhydrous in pre-workouts. We would have much preferred to see something tried-and-tested, such as Creatine Monohydrate instead.



Beta-Alanine has mixed reviews from most people. This is because it’s shown to be both beneficial and cause a side effect; studies show it can boost your muscular endurance, but also cause itchy & tingly skin too.

As a result, we personally prefer to avoid Beta-Alanine, as we don’t like the side effect (but in fairness, it is a completely harmless side effect that’ll only distract you, without causing any damage at all).

Consequently, we’ll leave the analysis of Beta-Alanine up to personal preference, as it does deliver a benefit to improve your gym session.

But we will remind you that Creatine Monohydrate offers the same benefit without causing any side effects.


L-Tyrosine is known for being a ‘brain booster’ ingredient, as it’s shown to improve your cognition. This can be useful, as an increase in focus an strengthen your mind-muscle-connection.

However, Arc Reactor contains Caffeine Anhydrous, which is usually enough to boost your cognition for the purposes of a gym session enough.

For this reason, we believe L-Tyrosine to be more useful in a nootropic supplement. But as we mentioned, it’s a great ‘bonus’ in Arc Reactor too.

Lion’s Mane Mushroom Extract 

Also known as Yamabushitake, this is another ‘brain booster’ that’s been used to enhance cognition. Again, this is another ‘bonus’ addition to Arc Reactor, but there’s no real need for it here.

Overload of Stimulants 

We mentioned at the start of this review that Arc Reactor contains a slightly over-dosed amount of Caffeine Anhydrous; we usually advise you to consume under 200mg per serving to stay safe.

However, the worst part is that Granite Supplements has also added 2 other stimulants (Theacrine and Theobromine). This simply increases your risk of jitters, so we recommend anyone with a low tolerance to choose a pre-workout containing less stimulants.

Ginseng Extract 

All you’re shown on the nutrient profile for Arc Reactor is ‘fermented ginseng extract’, so we’re not sure what type of ginseng this is.

If it’s Panax Ginseng, then we’re not sure why it’s been added; Panax Ginseng is better known for its ability to improve your testosterone levels when dosed higher (at least 100mg).

As a result, this is simply another ‘bonus’ addition to Arc Reactor here.


See Your Best Options In Our
Top 3 Pre-Workouts Page

Side Effects

The main concern we have with Arc Reactor, is that it contains an overload of stimulants (Caffeine Anhydrous, Theacrine and Theobromine). This might be an issue for those with a low tolerance to stimulants, and potentially might cause jitters and energy crashes.

However, we’ll also point out that Betaine Anhydrous can cause fishy odors in your breath and sweat. Beta-Alanine is known for causing itchy & tingly skin too (a side effect officially known as paresthesia).

Here are the potential side effects of taking Arc Reactor: 

  • Jitters (Overload of Stimulants)
  • Energy Crashes (Overload of Stimulants)
  • Fishy Breath & Sweat (Betaine Anhydrous)
  • Itchy & Tingly Skin (Beta-Alanine)

Arc Reactor Review Conclusion

Arc Reactor is a respectable product that has many good features; our favorite is the great 6,000mg dosage of L-Citrulline, which will reliably enhance your muscle pumps.

However, there has been small mistakes made, such as the overload of stimulants. As a result, we believe that there are better pre-workouts available for a similar price-tag.


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