In the realm of the best pre-workout supplements, there are different formulations for practically every need — some can be quick pick-me-ups, some are best for in-gym focus, and others are high-octane sparks of energy to increase power output. Building off Cellucor’s C4 Original platform, C4 Ultimate pre-workout is a caffeine-rich blend to help you charge through even the toughest reps and sets. However, while this high-stim caffeine content may be beneficial to some, does this supplement live up to its “Ultimate” moniker?
After testing this pre for multiple weeks, I think it can be a good introduction to high-stim pre-workouts. The caffeine content is there, but you aren’t overloaded with other sensations brought on by loads of other ingredients like beta-alanine. In this Cellucor C4 Ultimate pre-workout review, we’ll investigate the powder’s formulation as well as its performance in regard to taste, solubility, side effects, and more. For more information on how we test supplements for our content, be sure to read our BarBend supplement testing methodology page.
As a high-stim version of C4 Original pre-workout, C4 Ultimate from Cellucor packs in 300 milligrams of caffeine per serving. The eight available flavors are also inviting, giving you the power to take your energy stores to the next level with each workout.
Medical disclaimer: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. It’s always a good idea to talk to your doctor before beginning a new fitness, nutritional, and/or supplement routine. Individual needs for vitamins and minerals will vary.
Main Takeaways
- C4 Ultimate is available for roughly $2 per serving — a reasonable price point considering the increased caffeine dosage per scoop.
- While high on caffeine, our experts have noted that C4 Ultimate is underserved when it comes to other key pre-workout ingredients such as beta-alanine and citrulline.
- C4 Ultimate is available in eight flavor offerings, which can be ideal for mixing tastes up every now and again.
Cellucor C4 Ultimate Pre-Workout Specs
| Price Per Serving | $2.00 |
| Caffeine Per Serving | 300mg |
| Key Ingredients | C4® Super Citrulline Pump Matrix, L-citrulline, citrulline nitrate, citrulline malate, CarnoSyn® beta-alanine, CON-CRET® creatine HCl, creatine nitrate, taurine, caffeine anhydrous, AlphaSize® alpha-GPC, theacrine, toothed clubmoss, rauwolfia vomitoria root bark extract |
| Sweeteners Used | Acesulfame K, sucralose |
| Available Flavors | Arctic Snow Cone, Bare Knuckle Blood Orange, Freedom Ice, Icy Blue Razz, Mango Foxtrot, Nectarine Guava Knockout, Pomegranate PileDrive, Strawberry Watermelon |
| Third-Party Testing | None |
C4 Ultimate is yet another pre-workout powder from Cellucor, joining the likes of C4 Original and C4 Sport stables along with pre-canned C4 energy drinks. In addition to the baseline C4 Ultimate formulation, Cellucor also offers C4 Ultimate Shred and Strength renditions, which vary up dosages of key ingredients to better support fat burn or muscle growth. For the sake of this review, though, we’re focusing on the OG C4 Ultimate.
Each container of this popular pre-workout contains 20 servings, which equates to roughly $2 per dosage. Additionally, you can opt into “Subscribe & Save” services on select retail sites that can drop this cost even lower.
What places C4 Ultimate among the strongest pre-workouts, though, is its heightened caffeine dosage per serving. The 300 milligrams butts right up against the recommended daily allowance of 400 milligrams, so it’s safe to say this is a high-octane formulation that’s best reserved for seasoned pre-workout users. (1) For reference, C4 Ultimate is the equivalent of over three cups of coffee. (2)
In addition to the caffeine, C4 Ultimate features common pre-workout ingredients often found in different pre-workout formulations including beta-alanine, creatine, and citrulline nitrate, among others. That said, “It’s not about quantity, but quality and proper dosages of evidence-backed ingredients,” says Amy Goodson MS, RD, CSSD, LD — and unfortunately, many of these ingredients fall below recommended serving sizes.
The beta-alanine content, for example, is listed at 3.2 grams per serving. “Much of the research surrounding beta-alanine recommends a dose between 4 and 6 grams,” notes Chelsea Rae Bourgeois, registered dietitian nutritionist and our expert reviewer. (3) The citrulline complex is also underserved at 6 grams of L-citrulline, citrulline nitrate, and citrulline malate. Studies report that this metric should be closer to 8 grams for optimal blood flow benefits. (4)
Despite the shortcomings with some ingredient dosages, C4 Ultimate does feature a robust flavor roster of eight unique tastes. There are classics from the brand such as Icy Blue Razz and Strawberry Watermelon as well as adventurous palate pleasers including Arctic Snow Cone, Bare Knuckle Blood Orange, and Nectarine Guava Knockout. As is the case with most pre-workouts — even the best natural pre-workouts — the flavors often favor a sweet or citrusy profile, but we’re happy with the array of options.
Finally, C4 Ultimate does not feature third-party testing and certification. For those looking for formulations tested and approved by outside entities, you’re best off with Cellucor’s C4 Sport and C4 Sport Ripped pre-workout varieties, which are NSF Certified for Sport.
Who Should Use / Who Shouldn’t Use Cellucor C4 Ultimate Pre-Workout
Naturally, not every pre-workout is going to jive with every athlete, and C4 Ultimate is no different. Below are a few groups we feel could benefit from this Cellucor supplement, as well as some that may be better off steering clear of the caffeine-rich formulation.
Recommended for:
- Individuals wanting an affordable pre-workout close to the average $1.85 cost per serving
- Caffeine-tolerant athletes looking for higher doses within their pre-workout powder
- Those wanting to avoid the heavy “skin tingles” associated with optimal beta-alanine dosages
Not Recommended for:
- Individuals sensitive to excessive caffeine consumption
- Strength athletes that require a third-party tested pre-workout
- Those looking for a pump-centric pre-workout with citrulline dosages in line with the daily recommended allowance
Our Experience Using Cellucor C4 Ultimate Pre-Workout
At BarBend, we’ve tested over 100 different pre-workout supplements through the years covering the gauntlet from the best pre-workouts for weight loss to the best beta-alanine-free pre-workouts, best high-stim formulations, and more. We applied our tried-and-true testing methodologies to C4 Ultimate, too, examining the supplement’s formulation and ingredients as well as its taste, solubility, post-consumption effects, and more. We then rated our findings on a scale of 1 (lowest) to 5 (highest). Here are some of our findings.
Ingredients and Formulation
When it comes to the ingredients, I was happy to see there was a sense of transparency in dosages, meaning every included component featured a measurable serving across the ingredients list. This can be helpful when trying to establish just how much of a vitamin or nutrient you’re consuming and how the supplement as a whole fits into your daily routine. Other pre-workouts I’ve trialed do feature proprietary blends, giving you plenty of room to question just how much of a key ingredient you’re actually consuming.
I also appreciate the heightened caffeine serving of 300 milligrams. I, admittedly, am tolerant to caffeine, so I need more of a spark to get my body charged up. You definitely feel the effects after 20 minutes, and I felt as if my energy levels were maintained throughout the course of my training.
However, we rate the formulation at 3.75 out of 5 given that multiple key pre-workout ingredients are underdosed. “C4 Ultimate contains many of the prominent pre-workout compounds, but the dosing for some may not hit all the marks, according to the latest research,” notes Chelsea Rae Bourgeois, our expert reviewer.
This underserved notion is most prominently showcased with the beta-alanine found in C4 Ultimate. Listed under the branded CarnoSyn beta-alanine moniker, this pre-workout features 3.2 grams of the compound. Current studies recommend between 4 and 6 grams of beta-alanine. (3) This translates to a lower sense of muscular endurance during workouts, which I notice toward the end of my sessions. Those last few reps and sets are more of a struggle and you get a sense of depletion that can overwhelm your in-gym focus.
The lower beta-alanine counts aren’t all negative, though. Given the lower dose, you don’t feel as much of the all-too-common “skin tingles.” This could be a blessing for athletes who typically opt for some of the best pre-workouts without beta-alanine, provided they’re willing to pair that with a higher caffeine serving.
Taste
Like the best-tasting protein powders, having a flavorful pre-workout can go a long way in ensuring you’re energized for workouts each day. I’ve always been a fan of Cellucor C4 pre-workout flavors and am pleased the tradition continues with C4 Ultimate. I sampled the Strawberry Watermelon flavor for this testing cycle, although Icy Blue Razz still holds a special place in my palate from years gone by.
The taste itself is sweet, but I’m not overwhelmed by the sugary sensations. The strawberry and watermelon notes combine in an appealing manner, and I wouldn’t put it past people to sip this rather than pound it down in just a few gulps.
I score the taste at 4.5 out of 5, too, since I like the recommended 12 fluid ounces of water to balance out the potency. Some pre-workouts call for 8 ounces of liquid, which, in my opinion, creates too rich of a flavor and leaves you overstimulated. Plus, the larger beverage size lends itself to pacing through the blend rather than trying to quickly down your mixture before hitting the gym.
Solubility
As enjoyable as this C4 Ultimate is when it comes to taste, I do wish Cellucor paid a little more attention to the powder’s mixability. I typically use a BlendJet for my supplement mixtures, which is a cross between your standard countertop blender and some of the best shaker bottles out there. I just press a button and the concoction is mixed, keeping my arm workouts reserved for the gym.
Unfortunately, this Cellucor offering required some extra pulses to get all the powder mixed with the allotted water, as seen in the residue that collects at the bottom of your cup. This is a minor inconvenience, especially when my BlendJet keeps blending procedures convenient, but it is a noteworthy negative when compared to other pre-workout powders on the market. Overall, I’d rate the solubility at 3.5 out of 5 and recommend athletes take their time when mixing up a serving for themselves.
Price Per Serving
C4 Ultimate comes in at roughly $2 per serving, which is slightly higher than the average $1.85 price of other pre-workouts. However, I still score this Cellucor offering at 4 out of 5 for the category given that you’re receiving more caffeine per dose than you would with other powders. Stronger pre-workouts typically cost more, regardless, so I’m willing to pay the extra $0.15 for the sake of a better energy jolt.
[Related: Best Cheap Pre-Workouts]
Additionally, you can find this C4 Ultimate formulation on multiple third-party retailers offering “Subscribe & Save” services. These purchasing platforms can be great for lowering overall costs while also keeping you well-stocked with go-juice. If you’re looking for a convenient way to keep your pre-workout reserves in check throughout the year, this could be a worthwhile shopping experience.
Third-Party Testing
Unfortunately, C4 Ultimate does not carry any third-party certifications, leading us to score the pre-workout at 2 out of 5 for the category. That said, this supplement is processed in a cGMP facility, meaning the manufacturing protocols follow strict guidelines set forth by FDA representatives. This does offer some positive notes regarding Cellucor’s product quality and purity, but it would be nice to see some additional accreditation across the packaging.
What to Consider Before Buying Cellucor C4 Ultimate Pre-Workout
When choosing a pre-workout to support your fitness goals, there are multiple factors to consider prior to finalizing your cart. This is especially true when searching for high-stim pre-workouts carrying heightened caffeine counts. Below are some points of emphasis we recommend you ponder over when looking for your next supplement of choice.
- Ingredient Dosages: Every common pre-workout ingredient — even the best natural pre-workout ingredients — has a recommended daily allowance assigned to it, and if you’re underserved, you could be missing out on the benefits of each compound. Do some research (or let us do it for you!) prior to purchase to confirm your daily serving of pre-workout is in-line with these measurements.
- Available Flavors: Having a pre-workout that offers multiple flavors can be great over time. Having different tastes of the (relatively) same formulation can help defend against flavor fatigue, or, when you tire of a specific profile and are searching for something new and exciting.
- Third-Party Testing: Amy Goodson MS, RD, CSSD, LD tells BarBend, “Opt for products that are third-party tested for quality, potency, and purity, ensuring they are free from banned substances and contaminants. Reputable certifications include NSF Certified for Sport and Informed Choice.”
- Caffeine Content: The recommended daily allowance for caffeine is 400 milligrams, so be sure your pre-workout doesn’t exceed this measurement. This also means adding up your daily caffeine intake from, say, your morning coffees and midday energy drinks — adding a high-stim pre-workout to this regimen could place you over the edge. If you absolutely can’t part with your morning coffee, you might want to choose one of the best non-stim pre-workouts instead of this blend to ensure you’re not exceeding the 400 milligram daily recommended limit.
Cellucor C4 Ultimate Pre-Workout Vs. Competitors
As we’ve established, there are a ton of pre-workouts on the market, each with its own perks, formulations, and flavor notes. Narrowing your search down to just a single product can be difficult because of this large field, so it helps to compare products side by side whenever possible. Below, we’ve outlined two popular pre-workout options similar to Cellucor C4 — Transparent Labs BULK Black and Jacked Factory Wick Mode.
| Cellucor C4 Ultimate Pre-Workout | Transparent Labs BULK Black | Jacked Factory Wick Mode | |
| Price Per Serving | $2.00 | $1.67 | $2.00 |
| Caffeine Per Serving | 300mg | 200mg | 300mg |
| Key Ingredients | C4® Super Citrulline Pump Matrix, L-citrulline, citrulline nitrate, Citrulline malate, CarnoSyn® beta-alanine, CON-CRET® creatine HCl, creatine nitrate, taurine, caffeine anhydrous, AlphaSize® alpha-GPC, theacrine, toothed clubmoss, rauwolfia vomitoria root bark extract | Citrulline malate, beta-alanine, BetaPure™ betaine anhydrous, taurine, L-tyrosine, AlphaSize® alpha-GPC, PurCaf® organic caffeine, L-theanine, theobromine, Senactiv®, Bioperine®, boron citrate | L-citrulline, beta-alanine, L-tyrosine, caffeine anhydrous, Cognizin® citicholine, Infinergy™ caffeine malate, L-theanine, theobromine, Astragin® |
| Sweeteners Used | Acesulfame K, sucralose | Stevia extract | Sucralose |
| Available Flavors | Arctic Snow Cone, Bare Knuckle Blood Orange, Freedom Ice, Icy Blue Razz, Mango Foxtrot, Nectarine Guava Knockout, Pomegranate PileDrive, Strawberry Watermelon | Strawberry Lemonade, Blue Raspberry, Peach Mango, Tropical Punch, Watermelon, Strawberry Kiwi, Sour Grape, Black Cherry, Pineapple Coconut | Osaka Cherry Blossom, Baba Yaga Blue Razz, Last Tropical Sunrise |
| Third-Party Testing | None | Informed Choice | None |
When it comes to some of our favorite pre-workouts, the Transparent Labs BULK series continues to earn high marks. Transparent Labs BULK Black is the brand’s high-stim rendition delivering 200 milligrams of caffeine per serving along with a properly dosed formulation free of artificial sweeteners or colorings. BULK Black is also cheaper than C4 Ultimate at $1.67 per serving and is third-party certified by Informed Choice. However, This TL offering doesn’t feature creatine within its makeup — a helpful additive when looking to build muscle and promote strength increases in training. (5)
Jacked Factory Wick Mode features the same caffeine content and price point as C4 Ultimate, and our testers have said the effects are practically immediate, noting increased energy stores and heightened focus within 15 minutes post-consumption. We feel C4 Ultimate is a more approachable high-stim pre-workout, though, given the amount of powder in each dose. The 16.4 grams of C4 Ultimate creates a nice consistency with the recommended 12 fluid ounces of water, while Wick Mode’s 19.6 grams can be somewhat potent with its recommended 10 to 14 fluid ounces.
Places to Buy Cellucor C4 Ultimate Pre-Workout
Cellucor C4 Ultimate pre-workout can be purchased online directly from the brand’s retail site as well as from popular third-party retailers including Amazon, Walmart, GNC, The Vitamin Shoppe, and others.
Customer Experience and Brand Reputation
Cellucor has been a popular sports nutrition brand for over 20 years churning out some of the best BCAA supplements, fat burners, testosterone boosters, and (of course) pre-workouts. To reach Cellucor with any inquiries, you can use the Live Chat feature located at the bottom right of the brand’s retail site. You can also speak to a customer service representative via phone at (866) 927-9686 or email at support@c4energy.com.
C4 Ultimate has earned an average 4.5 out of 5 rating based on over 2,500 reviews on Amazon. “I’m very satisfied with this pre-workout. You don’t crash or lose energy with it, and it tastes great,” says one positive customer response.
Our Final Verdict on Cellucor C4 Ultimate Pre-Workout
If you’re interested in dipping your toes in the high-stim pre-workout category, C4 Ultimate may be a good option to start with. You do feel a good surge of energy from the 300 milligrams of caffeine and the (admittedly) underserved ingredients like beta-alanine and citrulline aren’t overwhelming when it comes to side effects. Naturally, there are better-dosed formulations on the market, but it can be best to take one high-stim response at a time rather than trying to manage skin tingles, amped blood flow, and a heavy caffeine rush simultaneously.
Regardless of your aspirations, it’s always wise to read through your pre-workout ingredients list prior to purchase. Look and research to ensure you’re getting proper dosages of key ingredients while also keeping your personal sensitivities top of mind. From there, you can simply narrow it down to an appealing flavor at an approachable price point.
Cellucor C4 Ultimate Pre-Workout FAQs
How much caffeine is in Cellucor C4 Ultimate pre-workout?
C4 Ultimate pre-workout contains 300 milligrams of caffeine per serving.
How much does Cellucor C4 Ultimate pre-workout cost?
Cellucor C4 Ultimate is available online in 20-serving tubs at roughly $2 per serving.
How long before a workout should I take Cellucor C4 Ultimate?
Per the packaging, Cellucor recommends taking one level scoop of C4 Ultimate pre-workout with 12 fluid ounces of water 20 to 30 minutes prior to training. In my experience, you can begin to feel the pre-workout’s effects between 20 and 25 minutes post-consumption.
References
- Mayo Foundation for Medical Education and Research. (2022, March 19). Caffeine: How much is too much?. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678
- Bjarnadottir, A. (2024, October 14). How much caffeine in a cup of coffee? A detailed guide. Healthline. https://www.healthline.com/nutrition/how-much-caffeine-in-coffee
- Trexler, E. T., Smith-Ryan, A. E., Stout, J. R., Hoffman, J. R., Wilborn, C. D., Sale, C., Kreider, R. B., Jäger, R., Earnest, C. P., Bannock, L., Campbell, B., Kalman, D., Ziegenfuss, T. N., & Antonio, J. (2015). International Society of Sports Nutrition Position Stand: Beta-alanine. Journal of the International Society of Sports Nutrition, 12(1). https://pmc.ncbi.nlm.nih.gov/articles/PMC4501114/
- Gough, L. A., Sparks, S. A., McNaughton, L. R., Higgins, M. F., Newbury, J. W., Trexler, E., Faghy, M. A., & Bridge, C. A. (2021). A critical review of Citrulline Malate Supplementation and Exercise Performance. European Journal of Applied Physiology, 121(12), 3283–3295. https://pmc.ncbi.nlm.nih.gov/articles/PMC8571142/
- Hall, M., Manetta, E., & Tupper, K. (2021). Creatine supplementation: An update. Current Sports Medicine Reports, 20(7), 338–344. https://pubmed.ncbi.nlm.nih.gov/34234088/
