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Cellucor’s C4 Ultimate Pre-Workout is a well-known choice among athletes, bodybuilders, those looking to build muscle, or people aiming for weight loss, mostly because of its amped-up formulation. 

RELATED: Best Pre-Workout for Muscle Gain

You get effective dosages of several ingredients, plus 300 milligrams of caffeine per serving—the high end of the range for pre-workout powders. While everything looks good on paper, we had to test it ourselves to give our opinion on effectiveness, taste, and solubility, among other things. 

In this C4 Ultimate Pre-Workout Review, I—a certified nutritionist—will tell you the need-to-know info about the brand, highlight GGR expert tester, USAW-L2, and personal trainer Jacob Penner’s experience testing this powder, and who we recommend it for.

Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider. GGR also recommends choosing a product that has been third-party tested for quality.

We’re Pre-Workout Pros

Our team of GGR product testers is made up of personal trainers, certified nutrition coaches, weightlifting coaches, and elite-level athletes who have formally (and informally) tested dozens of pre-workouts. We put each one through a rigorous step-by-step supplement testing methodology that includes assessing taste, solubility, dosage, third-party testing, company policies, and customer service.

We also rely on registered dietitians and other subject-matter experts to help assess formulation, dosage, and potential side effects for any supplements we recommend. Most importantly, we never recommend anything that we wouldn’t use ourselves. 

C4 Ultimate Pre-Workout

C4 Ultimate Pre-Workout

GGR Score: 4.2 starstarstarstarstar

Product Highlights

  • Pre-workout supplement with 300 mg of caffeine
  • 4 available flavors
  • Contains beta-alanine, L-citrulline, creatine, and taurine
  • Claims to help improve alertness, muscular performance, and muscular endurance

Pros & Cons

Pros

  • 300 mg of caffeine
  • No artificial dyes or flavors
  • Subscription option to save
  • Contains beta-alanine and L-citrulline

Cons

  • Expensive price per serving
  • Not NSF Certified for Sport

Bottom Line

If you’re looking for a pre-workout to help you through low-energy days, C4 Ultimate Pre-Workout could be a good choice with a whopping 300 milligrams of caffeine per serving. At $45 for 20 servings, it’s a fairly pricey pre-workout, although there is an option to subscribe and save 30%---plus free shipping. Along with this, C4 Ultimate has pre-workout staples like beta-alanine, L-citrulline, and taurine. This pre-workout is available in four different flavors.

A Quick Look at C4 Ultimate Pre-Workout 

Cellucor is a sports nutrition company through and through. The company manufactures supplements focused on “maximizing your potential,” which, to them, really means improving endurance and efficiency for those with active lifestyles. 

They list six categories of supplements: amino acids/BCAAs, fat burners, sports nutrition, protein powders, testosterone boosters, and, of course, pre-workouts. (The company also offers zero-sugar energy drinks, aptly named C4 Energy.)

The C4 Ultimate Pre-Workout is one of 13 different types in the lineup. In addition to the C4 Original (check out our in-depth C4 Pre-Workout review), the pre-workout supplements are broken down into additional categories, like C4 Sport, C4 Ultimate Shred, and C4 Ripped. 

The Ultimate Pre-Workout is the next-level version of the Original Pre-Workout. It has a higher stimulant concentration and is made for advanced users. The brand says it’s formulated to enhance energy, alertness, pump, performance, and muscular endurance.

Before You Buy

  • This is a higher-stimulant version of the original pre-workout
  • It’s expensive, but you can save some money if you subscribe for recurring deliveries directly through the site
  • It contains artificial sweeteners and some dyes

Is C4 Ultimate Pre-Workout Worth It?

Whether or not the C4 Ultimate Pre-Workout is worth it really depends on where you are in your fitness (or supplement) journey and what you value in a pre-workout formula. Also, at $2.25 per serving, it’s definitely one of the pricier pre-workouts we’ve reviewed. 

A man opens up a can of C4 Ultimate Pre-Workout

Here’s who we think will love it and who should leave it.

Great for:

  • Experienced pre-workout users (it’s high in stimulants)
  • People who crave the beta-alanine tingle
  • Those okay with spending a little more for a pre-workout with a stacked ingredient list
  • Folks who don’t mind a few artificial ingredients

Not recommended for:

  • Those who want a lower-stimulant or stimulant-free pre-workout
  • Anyone who’s caffeine/stimulant sensitive
  • People who prefer to stay away from artificial sweeteners
  • Those on a tight budget

C4 Ultimate Pre-Workout Specs

Price per serving$2.25
Servings per container20 servings (one scoop serving size)
Caffeine per serving300 milligrams
FlavorsStrawberry Watermelon, Arctic Snow Cone, Icy Blue Razz, Orange Mango
Active IngredientsCitrulline (L-citrulline citrulline nitrate, citrulline malate), Carnosyn beta-alanine, creatine HCl and creatine nitrate, taurine, caffeine anhydrous, choline, theacrine (as TeaCrine), toothed clubmoss, Rauwolfia vomitoria root bark extract 
SweetenersAcesulfame K, sucralose
Other IngredientsNatural and artificial flavors, calcium silicate, silicone dioxide, citric acid, malic acid, FD&C blue #1

Experience Using C4 Ultimate Pre-Workout

Jacob Penner, personal trainer, USAW-L2, and pre-workout expert, tested C4 Ultimate by using it before Olympic weightlifting and strength workouts (including several Squatober workouts). Here’s a breakdown of his experience with this potent pre-workout.

Price Per Serving

There’s no way around it: C4 Ultimate Pre-Workout is expensive. Because of this, Jacob gave it 1 star out of 5 for price.

If you buy directly from the website, it breaks down to $2.25 per serving. For reference, most pre-workout powders fall under $2 per serving, but some can be as much as $3. So it’s not the most expensive, but it’s certainly not cheap either. 

If you sign up for a subscription through the site, the price does drop considerably. You’ll get 30% off your first order and then 20% off each order after that. 

RELATED: Best Cheap Pre-Workout

Formulation

“This feels like a natural progression from C4 that a lot of us have been looking for,” Jacob says. “The regular C4 is a good starter pre-workout for beginners. Ultimate feels like a good fit for those who maybe got used to doing multiple scoops of C4 or who are ready for more caffeine,” giving C4 Ultimate a 4.5 out of 5 for formulation.

A can of C4 Ultimate Pre-Workout sits next to a shaker cup with the Supplement Facts label displayed

It has research-based doses (and then some) of various pre-workout ingredients, including:

It’s a bit lower in creatine than we’d like to see; it has 1 gram of creatine nitrate and 1 gram of creatine HCl. Typically, we recommend pre-workouts that have at least 3 grams per serving (even better if it’s 5 grams, but most pre-workouts don’t contain that much), so it’s not too far off, but still worth nothing.

In addition to these main ingredients, there are also supportive ingredients like taurine, which has been shown to improve exercise performance and reduce soreness4.

Taste and Solubility 

C4 Ultimate earns perfect scores—5 out of 5—for taste and solubility (how quickly it dissolves). Jacob tried the “Sour Batch Bros,” which is no longer available but tastes just like Sour Patch Kids.

“It was so good. C4 always does a good job with flavors. I’ve been using C4 variations for more than a decade and I always like the flavor,” he adds.

At the time of writing, you can choose from four in-stock flavors: Strawberry Watermelon, Arctic Snow Cone, Ice Blue Razz (blue raspberry), and Orange Mango.

Side Effects

As for side effects, there was nothing out of the ordinary. Because this is a very stimulating pre-workout, Jacob notes that it is a “little tingly,” so be aware if that isn’t something you enjoy. It’s also worth noting that Jacob is an experienced pre-workout user, so beginners may find it more than a little tingly. If high-stim pre-workouts make you nervous, you may want to consider one of the best stim-free pre-workouts.

A person drinks a shaker cup of C4 Ultimate Pre-Workout in a kitchen with nice granite counters

Outside of that, there were only positives: Jacob said it made him feel more enthusiastic about lifting, and it only took about 15 minutes to kick in.

Third-Party Testing 

Unfortunately, C4 only third-party tests its sports line, which is all NSF-Certified for Sport. The other products aren’t third-party tested, but they are made in cGMP facilities, which means the manufacturing process follows rigorous guidelines verified by FDA reps. This is a nod to quality and purity, but ideally, we would like to see additional third-party testing.

Comparison to Kaged Pre-Kaged  

Kaged Pre-Kaged

Kaged Pre-Kaged Pre-Workout

GGR Score: 4.16 starstarstarstarstar

Product Highlights

  • Contains research-backed dosages of key ingredients like caffeine, creatine, and citrulline
  • Informed Sport-certified, meaning it’s been tested for quality assurance and banned substances. 
  • 7 flavors are available

Pros & Cons

Pros

  • Good formulation of research-backed ingredients
  • Label transparency
  • 7 flavors and users overwhelmingly like the taste

Cons

  • Big serving size
  • Expensive

Bottom Line

Kaged Pre-Kaged is expensive, but is formulated with research-backed dosages of key ingredients like caffeine, creatine, beta-alanine, and citrulline.

Kaged Pre-Kaged is another amped-up pre-workout powder boasting 274 milligrams of PurCaf® organic caffeine per serving. They’re similar in price and have a comparable active ingredient list.

The biggest callout here is that the Pre-Kaged has only 1.6 grams of beta-alanine compared to C4’s 3.2 grams, making it a better fit for those who don’t like the tingly sensation that can come with pre-workouts; you can thank (or curse) beta-alanine for that.

Kaged Pre-Kaged also contains betaine anhydrous, which C4 is missing. Betaine helps increase muscle endurance5 and helps you push through high-intensity workouts, so the Kaged may be a better option if HIIT is your jam.

Another difference is that Kaged Pre-Kaged has an ORAC blend—a mix of fruit and vegetable powders that provide antioxidants that can help support overall health. It also has coconut water powder for some added electrolytes to aid hydration.

If you want to learn more, check out our Kaged Pre-Kaged review.

C4 Ultimate Pre-WorkoutKaged Pre-Kaged 
Price per serving$2.25$2.25
Servings per container20 servings20 servings
Caffeine per serving300 milligrams274 milligrams
FlavorsStrawberry Watermelon, Arctic Snow Cone, Icy Blue Razz, Orange MangoFruit Punch, Berry Blast, Cherry Bomb, Pink Lemonade, Grape, Krisp Apple, Orange Krush
Active IngredientsCitrulline (L-citrulline citrulline nitrate, citrulline malate), Carnosyn beta-alanine, creatine HCl and creatine nitrate, taurine, caffeine anhydrous, choline, theacrine (as TeaCrine), toothed clubmoss, Rauwolfia vomitoria root bark extract L-Citrulline, BCAAs, betaine anhydrous, beta-alanine, creatine HCl, taurine, tyrosine, organic caffeine
SweetenersAcesulfame K, sucraloseStevia, sucralose
Other IngredientsNatural and artificial flavors, calcium silicate, silicone dioxide, citric acid, malic acid, FD&C blue #1Natural flavor, malic acid, citric acid, beet root powder, sea salt, silicon dioxide, calcium silicate

Customer Experience 

Jacob gave Cellucor a 4.5 out of 5 for customer service because the company has a generous return policy. You have 90 days to return the pre-workout for a full refund if you don’t like it, which applies even if you don’t purchase from their website directly, as long as you buy your pre-workout from an authorized retailer.

Ordering C4 Ultimate Pre-Workout

Ordering is straightforward. You have the option for a one-time purchase or a recurring subscription. 

A shaker cup is next to a well-posed can of C4 Ultimate Pre-Workout  with the front label displayed prominently

If you opt for the subscription, you’ll get 30% off your first order and 20% off all your following orders. So you can save a significant amount of money. All subscriptions ship free regardless of spend, while you’ll have to spend $55 to get free shipping on a single purchase without a subscription.

You can also find C4 Ultimate on Amazon, but be aware that there are often counterfeit sellers, so you want to be sure you’re buying from an authorized, reputable retailer.

Customer Reviews

Overall, customers are happy with C4 Ultimate. The pre-workout powder has an average 4.7-star rating on the brand’s site and a 4.4-star rating on Amazon with over 3,500 reviews.

Some common themes are that customers think the pre-workout is really effective and gives them enough strength and endurance to get them through strenuous workouts. While some call out the tingle, those who are used to caffeine say it doesn’t give them the jitters.

“I usually take two-thirds of a scoop and the pumps are incredible. It doesn’t give me jitters because I’m used to being caffeinated, but you may get tingly if you don’t have a tolerance to beta alanine. Definitely would recommend!” writes an Amazon reviewer.

A person stands in a kitchen preparing a dose of C4 Ultimate Pre-Workout

Taste is hit or miss. Some say it’s terrible, others say it’s okay, and others describe it as wonderful. Basically, this subjective measure will really come down to personal preference. 

“I don’t like the taste of this, but it isn’t horrible. [The taste] is something you can survive, but I don’t crave it,” writes one Amazon reviewer.

Final Verdict of Our C4 Ultimate Pre-Workout Review

We think the C4 Ultimate Pre-Workout is an excellent option for advanced pre-workout users who aren’t sensitive to caffeine (and don’t mind the price tag). It has research-backed doses of most major pre-workout ingredients and got high marks for formulation, taste, and solubility during our testing. 

If it’s your first time taking a pre-workout or you want a stim-free version, we recommend you check out our roundup of the best pre-workouts for more options that are better suited to you.

  • Great for advanced users; beginners should skip it
  • There are more budget-friendly options out there, but we think the list of pros for this one outweigh this particular con
  • If you want a lower-caffeine version, check out the C4 Original instead.

Full Rating

C4 Ultimate Pre-Workout

If you’re looking for a pre-workout to help you through low-energy days, C4 Ultimate Pre-Workout could be a good choice with a whopping 300 milligrams of caffeine per serving. At $45 for 20 servings, it’s a fairly pricey pre-workout, although there is an option to subscribe and save 30%---plus free shipping. Along with this, C4 Ultimate has pre-workout staples like beta-alanine, L-citrulline, and taurine. This pre-workout is available in four different flavors.

Product Brand: C4

Product Currency: $

Product Price: 44.99

Product In-Stock: InStock

Editor's Rating:
4.2

C4 Ultimate Pre-Workout Rating

Price per serving – 1
Formulation – 4.5
Taste – 5
Solubility – 5
Side effects – 4
Third-party testing – 5
Customer service – 4.5
Customer reviews – 4.7
Buy Now

C4 Ultimate Pre-Workout: FAQs

How much caffeine is in C4 Ultimate?

There are 300 milligrams of caffeine per serving. That’s equivalent to about three 8-ounce cups of brewed coffee.

What are the negatives of C4 Pre-Workout?

This particular C4 pre-workout is high in caffeine, which can be a negative for those who are sensitive and feel jittery when taking a pre-workout, even in lower amounts. It also has artificial sweeteners and dyes, which can be a con for those looking for a more natural option. Lastly, C4 Ultimate is considered expensive at $2.25 per serving but does have highly effective doses.

Who should not take C4?

Because C4 Ultimate is high in caffeine, those sensitive to caffeine’s effects may want to avoid it. This also goes for those with anxiety, who may be even more affected. Women who are pregnant or nursing should also avoid stimulant-based pre-workouts.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.

References

1. Fiani, B, Zhu, L, Musch, BL, et al. The Neurophysiology of Caffeine as a Central Nervous System Stimulant and the Resultant Effects on Cognitive Function. Cureus. 2021;13(5):e15032. doi:10.7759/cureus.15032

2. Gonzalez, AM, Trexler, ET. Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. J Strength Cond Res. 2020;34(5):1480-1495. doi:10.1519/JSC.0000000000003426

3. Hobson, RM, Saunders, B, Ball, G, Harris RC, Sale C. Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012;43(1):25-37. doi:10.1007/s00726-011-1200-z

4. Kurtz, J.A., VanDusseldorp, T.A., Doyle, J.A. et al. Taurine in sports and exercise. J Int Soc Sports Nutr. 2021;18(39). doi: 10.1186/s12970-021-00438-0

5. Arazi, H, Aboutalebi, S, Taati, B, Cholewa, JM, Candow, DG. Effects of short-term betaine supplementation on muscle endurance and indices of endocrine function following acute high-intensity resistance exercise in young athletes. J Int Soc Sports Nutr. 2022;19(1):1-16. doi:10.1080/15502783.2022.2041988

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