Is C4 Bad For You? An Ingredient Analysis

Is C4 Bad For You? An Ingredient Analysis

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Disclaimer: None of the information in this article constitutes medical advice. All statements are merely the opinion of the writer(s). We recommend that individuals follow their doctor’s guidance in regard to energy drinks

C4 is a popular energy drink brand. The company sells both canned drinks and pre-workout powder, and claims that their product line “fights fatigue with clinically studied ingredients.”

But does C4 contain ingredients shown in research studies to improve energy levels, or are these just marketing claims? Does the brand use any potentially unhealthy additive ingredients? What do medical experts have to say about energy drinks? And how do real users rate and describe the effects of C4 energy drinks?

In this article we’ll answer all of these questions and more as we analyze the ingredients in C4 based on medical studies to give our take on whether or not the popular energy drinks are bad for you.

We’ll share YouTube videos on C4 from credentialed medical professionals, and feature unsponsored customer reviews.

Ingredient Analysis

C4 ingredients

The ingredients in C4 Original, Frozen Bombsicle flavor are shown above.

Caffeine is one of the most effective compounds for enhancing energy, and is included in most commercial energy drinks. C4 contains 200 milligrams (mg) of caffeine, which is an effective dose.

Caffeine is clinically shown to improve both mental and physical energy (source 1, source 2).

Beta-alanine was shown in a 2012 medical review to reduce fatigue, although the dose doesn’t appear to be published on C4’s website.

Betaine was shown to improve muscular endurance in a 2009 clinical trial, which suggests that it supports physical energy improvements.

While there are some research-backed ingredients in C4 for supporting energy, there are also some inactive ingredients that may be questionable from a health perspective.

Sucralose is an artificial sweetener that was shown to worsen insulin function in a clinical trial published in the Nutrition Journal.

Citric acid can cause whole-body inflammation in some individuals, as documented in a medical review published in the Toxicology Reports journal.

Natural flavors may be a healthier alternative to artificial flavors, but we still consider it to be a questionable ingredient given the current state of research, as we discussed at length in our Energy Renew reviews article on another energy supplement containing this ingredient.

Potassium sorbate is a preservative, and acesulfame potassium is another non-caloric sweetener.

Overall, we consider C4 likely to improve energy levels, and from a strictly energy perspective, it’s a great formulation. Most energy drinks that we’ve reviewed on Illuminate Health contain only one active ingredient supporting energy (typically caffeine), while C4 contains several.

We don’t necessarily consider C4 to be bad for you in moderation, but we would not call this drink healthy, given the additive ingredients highlighted above.

But do medical experts consider energy drinks to be dangerous? We’ll discuss that and more in the next section.

Do Energy Drinks Even Work?


A YouTube video from the “Buzzfeed Multiplayer” channel tested the effects of three popular energy drinks on reaction time and more to see if they actually work:

Is C4 Healthier Than Other Energy Drinks?

C4 has a somewhat similar formulation to other energy drinks we’ve recently reviewed. The ingredient list for Red Bull is shown below:

Red Bull ingredients

We consider C4 to be healthier than Red Bull because it’s sugar-free and free of artificial dyes. 

Another huge benefit of C4 over other energy drinks we’ve reviewed is that the brand is NSF Certified for Sport. This certification program ensures that products are accurately labeled and free of contaminants.

For this reason alone, we consider C4 to be healthier than pretty much any other commercial energy drink, because we have not come across any with third-party certifications for product purity.

We Tried C4 Ourselves

C4 Energy UGC

One of our product testers named Jodie Steinberg tried a C4 Energy Drink. Here's her experience: 

Packaging was simple and convenient, as this was a standard metal can that was easy to open.

It was not overly sweet or artificially flavored where you could not enjoy it.

The taste was surprising in a good way. I expected it to be too sweet but it was just sweet enough. Given there is no actual sugar in it, I was impressed with the taste.

The product is an energy drink, so I drank it when I was quite tired during the day-time and had been quite anxious over recent personal events.

This drink woke me up without adding any anxiety from being overstimulated. It lasted for eight hours.

This product didn't cause any side effects, and I would consider purchasing it again.

Overall, I would rate C4 Energy Drink 10 out of 10.

Real People Try C4

A YouTube creator named “IAmTheJuanAndOnly” rated all C4 flavors from best to worst:

A YouTube creator named Cole Baker shares his first time ever trying C4’s powdered energy supplement:

Our Clean Energy Picks

Pique Breakfast Black Tea Sticks is our top whole food energy pick.

Black tea consumption is "associated with rapid increases in alertness and information processing capacity" according to a clinical trial, and Pique's tea is organic and comes in convenient stick packs that can be mixed into water, so a teapot or kettle are not needed.

Performance Lab Energy is our top multi-ingredient energy supplement.

This supplement contains acetyl-l-carnitine which can "improve energy status" according to a medical review published in the Neurochemical Research journal, as well as CoQ10 which "is an effective and safe treatment for reducing fatigue symptoms" according to a 2022 meta-study.

Illuminate Labs Panax Ginseng Extract is our top herbal energy pick.

Panax ginseng extract has been clinically shown to reduce mental fatigue and reduce physical fatigue, and our supplement is third-party tested to ensure its purity and potency.

All of the products recommended in this section are entirely free of ingredients we consider to be unhealthy.

Stay up-to-date on our research reviews


C4 is not healthy in our opinion.

While it does contain some effectively dosed active ingredients and should support both physical and mental energy levels, it also contains artificial sweeteners, flavoring additives, a preservative and citric acid.

Health-conscious consumers may wish to choose an energy product without these additive ingredients.

We do consider C4 to be healthier than most commercial energy drinks, given its lack of artificial dyes and flavors, and given its NSF certification that guarantees the purity and label accuracy of the product.

Most customer reviews we came across while researching this article had favorable things to say about the taste and energy-boosting effects of C4.