For serious athletes looking for a more potent, performance-enhancing pre-workout, Cellucor’s C4 Ultimate Strength may be just the thing you need to reach your loftiest fitness goals. With a powerful combination of stimulating and muscle-building ingredients backed by research, this product may help boost your workout.
Our nutrition and fitness experts focused on Cellucor’s C4 Ultimate Strength pre-workout, paying close attention to ingredients, efficacy, research supporting product claims, pricing, and more. In full transparency, we spelled out the pros and cons so you can make a well-informed purchase.
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.
Key product features
What you should know
Cellucor’s C4 Ultimate Strength is the brand’s most powerful pre-workout supplement, designed to provide “next-level” energy, strength, endurance, and mental focus.
- C4 Ultimate Strength combines well-researched ingredients like amino acids, two forms of creatine, elevATP®, caffeine, and nootropics in a unique blend to give you maximum energy and strength-building potential.
- This product is pricier than average for pre-workouts, at $3.00 per serving, but also contains creatine, which you will not find in most pre-workout supplements.
- C4 Ultimate Strength is ideal for athletes looking for a big boost of energy and strength gains from their pre-workout supplement.
- Cellucor’s products are third-party tested and NSF Certified for Sport.
Cellucor C4 Ultimate Strength pre-workout overview
Cellucor C4 Ultimate Strength is an advanced pre-workout designed for athletes looking for big boosts in energy, endurance, and focus. It’s Cellucor’s most powerful pre-workout in their product line-up. It includes three sources of stimulants, along with amino acids, creatine, peptides, plant extracts, nootropics, B vitamins, and electrolytes.
Reviewers like the energy and focus C4 Ultimate Strength provides, leading to more productive workouts. Some mention the stimulant effects can be slightly overwhelming, especially for anyone new to taking a pre-workout or for those sensitive to stimulants. For this reason, multiple users recommend starting with a half scoop to test tolerance and increasing the dose from there as appropriate.
C4 Ultimate Strength comes in four flavors: Sour Green Apple, Orange Popsicle, Frozen Bombsicle, and Watermelon. They are flavored with natural and artificial flavors and sweetened with sucralose and acesulfame potassium. Some users note the flavor is very sweet and many prefer to add a bit more water than the label calls for to help dilute the flavor.
This product receives positive feedback in the mixability category, making it a convenient on-the-go option.
Cellucor products are made in GMP-compliant facilities in the United States, ensuring product manufacturing follows industry best practices.
C4 does have a higher price point than many other pre-workout products on the market, at $3.00 per serving. It might be worth it, though, especially for athletes who use creatine supplements as part of their regimen. C4 Ultimate Strength combines the two, adding a convenience factor for those users. Cellucor offers a 90-day money-back guarantee, so if you are on the fence, you may feel more confident in trying it.
C4 Ultimate Strength ingredients
Endurance and performance complex
C4 Ultimate Strength’s “endurance and performance complex” includes 3.2 grams of Carnosyn® beta-alanine, 3 g each of L-citrulline and L-arginine, 1.25 g of BetaPower® betaine anhydrous, and 200 mg of PeptiPump® bioactive lentil peptides.
Research supports the use of beta-alanine supplementation to improve performance, especially during high-intensity activities. However, when paired with creatine, it may provide even greater results to physical and cognitive performance. Some users may experience paresthesia, a prickling or tingling sensation from this dose of beta-alanine. However, there are no reported safety concerns when taken in doses of less than 6.4 grams daily over four weeks. (1, 2)
L-citrulline and L-arginine are amino acids that are proven to boost nitric oxide levels and may improve performance by decreasing feelings of fatigue and muscle soreness post-workout. Research suggests that regular supplementation with L-citrulline, particularly in doses of 3.4-6 grams per day, may enhance endurance and boost aerobic capacity. These effects may help athletes perform at higher intensities during training and recover more effectively after each workout. Studies suggest supplementing arginine at 1.5-2 grams per day for four to seven weeks to enhance aerobic performance and 10-12 grams per day for eight weeks to improve anaerobic performance. (1, 3, 20)
Betaine anhydrous is an amino acid derived from sugar beets that is a potential nitric oxide and creatine booster. It may play a role in increasing strength and maintaining hydration. Furthermore, it might decrease symptoms of fatigue, which could lead to more productive sessions. However, most studies test doses ranging from 2-5 grams per day, while C4 Ultimate Strength gives you 1.25 grams. (1, 4)
Lastly, C4 Ultimate Strength includes PeptiPump®, which is a patented blend of lentil proteins with antioxidant, antihypertensive, and antidiabetic properties. More research is needed to determine its effectiveness in pre-workout supplements. (5)
Muscle and strength matrix
You’ll find two forms of creatine in C4 Ultimate Strength pre-workout. You get 4 grams of creatine monohydrate along with 1.5 grams of creatine nitrate.
Creatine is one of the most well-researched and safest ergogenic aids on the market. Evidence supports its potential to improve strength, power, sprinting, and even hasten recovery time after a workout. Supplementation recommendations vary, but studies show that 3-5 grams per day over a four week period leads to increased creatine stores and improved muscle performance, recovery, and growth. It does not appear useful for endurance sports and may lead to water weight gain in those athletes. (6, 1)
C4 Ultimate Strength also includes 2.4 grams of PeptiStrong® fava bean peptides that may enhance muscle recovery, improve muscle conditioning, and decrease fatigue, which may allow a faster return to training. (7)
The formula also includes ElevATP®, a blend of trace minerals and apple extract. One 2016 study showed improvement in exercise capacity after a single dose of 150 mg of ElevATP®. With continued daily ingestion over a 12 week period, it led to muscle hypertrophy. (8) However, more current research would be useful in determining whether or not this continues to be a valuable addition.
Ultimate energy, focus, and stimulant matrix
Included in their energy, focus, and stimulant blend is L-tyrosine, which is an amino acid involved in the production of neurotransmitters like dopamine and norepinephrine. Supplementation may be beneficial in improving cognitive performance, especially during stressful situations, but more research is needed to determine if this could be a beneficial supplement. (9)
C4 Ultimate Strength gives you a tri-stim blend of 300 mg of caffeine anhydrous, 50 mg of Dynamine®, and 10 mg of TeaCrine® to give you a powerful energy boost.
Caffeine is known for its ability to increase mental focus, acuity, and athletic performance. Men experience its beneficial effects while performing both aerobic and anaerobic activities, while women see less benefit with anaerobic activities. (10) Some users may experience negative side effects, especially with this large dose. Common side effects of caffeine ingestion include headache, nausea, restlessness, racing heart, and more. (10, 1) Athletes who are sensitive to caffeine, or prefer to avoid it, may benefit from a non-stim pre-workout supplement.
Dynamine® and TeaCrine® are added to this formula at doses of 50 mg and 10 mg respectively. They are alkaloid compounds similar to caffeine that are found in the leaves and seeds of the Coffea plant. It’s believed they offer similar stimulative effects to caffeine, but with fewer negative side effects. These ingredients are paired with caffeine to increase energy and mental focus. While there is limited research available to date, one 2020 study showed that supplementation in young, healthy individuals appears safe and without any negative effects on heart rate or blood pressure that some experience with caffeine intake. (11)
You also get 5 mg of toothed clubmoss, known as Huperzine A. It’s been shown to improve cognitive performance in certain populations and is a common addition to pre-workout supplements. However, the data to support this ingredient, especially for athletes, is lacking; therefore, it doesn’t seem to add much benefit to the supplement. (12)
Lastly, this blend includes 1 mg of Rauwolfia vomitoria root bark extract. It’s unclear why this is needed, as we were unable to find any studies involving this root bark extract on exercise, cognition, or physical performance, and very few recent research studies at all. Additionally, it appears that it may cause unwanted side effects such as blood pressure changes, depression, tremors, and more. (13)
B vitamins
Vitamins B6 and B12 are featured in this formula, which makes sense, as studies show these nutrients may improve exercise performance in relation to endurance and recovery outcomes. This is due to their role in energy metabolism, DNA synthesis, tissue repair, and red blood cell production. Athletes with diets low in B vitamins may especially benefit from this addition. (14, 15)
Electrolytes
Like many pre-workouts, C4 Ultimate Strength also includes a dose of essential electrolytes like calcium, phosphorus, magnesium, chloride, sodium, and potassium. Electrolytes are beneficial in maintaining proper hydration status by replenishing any potentially lost through sweat. When dehydrated, athletes may experience fatigue, headaches, muscle cramping, nausea, and more, which can impact recovery. (16, 17)
How long does C4 Ultimate Strength take to kick in?
Most users take this up to 30 minutes before they hit the gym to get the maximum benefit. Some may feel the energizing effects kick in a bit sooner. Other athletes enjoy sipping the pre-workout drink throughout their workout for a slower release of energy. There’s no right or wrong way to enjoy this supplement. It’s all a matter of personal preference here.
Customers note the boost in energy lasts about an hour and a half and then gradually wears off without that dreaded crash.
What customers are saying
This product has just 22 reviews on Amazon and averages 4.2 out of 5 stars. Most users agree that it provides a powerful burst of energy and endurance to help power through their workout.
“This C4 gives you the pump and energy you need without the jitters. It easily dissolves in cold water, and the taste is great. I recommend using 16 oz. of water rather than 12 oz., as it is a bit on the sweeter side,” wrote an Amazon customer with the username “EyE6SoLoMoN.”
“This is some of the most effective pre-workout I have ever taken, maximum effectiveness. The taste goes down well, and you will feel it kicking in. The value for money is good when you consider all of the other ingredients, and the high energy level it gives you during your workouts .”
Adam Brown, Amazon
However, some customers make note of the higher price point and high caffeine content as drawbacks to the supplement. Additionally, multiple reviews mention taking half a scoop at first until you know how your body will react to the stimulants in C4 Ultimate Strength.
Another Amazon customer states, “The taste is not bad, but I find this pre-workout powder to be too pricey for my budget and the caffeine in it is a bit much, okay a lot much. Less caffeine and a lower price tag would be nice.”
Specs
| Key ingredients | CarnoSyn® beta-alanine, L-citrulline, L-arginine, betaine anhydrous, lentil peptides, creatine monohydrate, fava bean peptides, creatine nitrate, elevATP®, L-tyrosine, caffeine, Dynamine™, TeaCrine®, toothed clubmoss, Rauwolfia vomitoria root bark extract, B vitamins, and electrolytes |
| Flavors | Sour green apple, orange popsicle, frozen bombsicle, and watermelon |
| Caffeine per serving | 300 mg |
| Serving size | 1 scoop (27.9 grams) |
| Servings per container | 20 |
| Price per serving | $3.00 |
| Third-party testing | Yes |
We’ve featured C4 Ultimate Strength pre-workout in:
Compare Cellucor C4 Ultimate Strength
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| Cellucor C4 Ultimate Strength | Transparent Labs Bulk Black | Nutricost Pre-X Xtreme | Legion Athletics Pulse | Kaged Pre-Workout Elite | |
| Rating | |||||
| Cost per serving | $3.00 | $1.83 | $0.63 | $2.25 | $3.00 |
| Caffeine per serving | 300 mg | 275 mg | 300 mg | 350 mg | 388 mg |
| Servings per container | 20 | 30 | 30 | 20 | 20 |
How we test pre-workout supplements
The nutrition and fitness experts at Fortune Recommends thoroughly research all products and evaluate them against high standards for ingredients, endurance, lean muscle support, focus, third-party testing, price, and more. Products are scored in each category, weighted based on their importance, and then averaged to give you a cumulative score of up to five. For a more detailed explanation check out our full pre-workout testing and rating system.
Testing criteria
Stimulant ingredients–35%
Pre-workouts are prized for their ability to give you energy and endurance to make it through tough workouts. Most pre-workout supplements contain stimulants like caffeine to create this desired effect. B vitamins and plant extracts are commonly found in the non-stim versions.
- Caffeine anhydrous
- PurCaf
- Di-caffeine malate
- Theobromine
Non-stimulant ingredients–10%
For athletes taking non-stim pre-workout supplements, vitamins and extracts may help provide that extra boost of energy to power through. We look at the research behind each ingredient and evaluate if its addition may potentially help athletes meet their fitness goals. Common non-stimulant ingredients include:
- Taurine
- Vitamins B12 and B6
- Niacin
Endurance–10%
Another perk of taking a pre-workout is its ability to improve physical and mental endurance, which in turn helps you crush your fitness goals.
You will likely find some of these common, well-researched players on the ingredient list:
- Beta-alanine
- Ancient peat and apple extract
- Rhodiola rosea
- L-carnitine
- Eleuthero root
- Astragalus root extract
- Astragin
- Senactiv
Nitric oxide production–10%
Nitric oxide production improves blood flow and nutrient delivery to skeletal tissue which may decrease muscular fatigue. Citrulline malate and beetroot both may play a role, but products with citrulline malate score a bit higher.
- Citrulline malate
- Beetroot
Lean muscle support–10%
Building muscle and improving strength are key benefits of pre-workout supplements. We look for 11 key nutrients that may play a role in contributing to strength gains.
- Creatine
- Betaine
- Leucine
- Taurine
- Isoleucine
- Valine
- Zinc
- Vitamin D
- BCAAs
- Boron
- Calcium
Sweeteners–10%
It’s important to pay attention to added sugar and sweeteners. We prefer products that are naturally sweetened and provide a minimal amount of added sugars per serving. Here’s how we rate each sweetener:
- Sugar–3%
- Honey, agave–3%
- Maltodextrin–3%
- Dextrose–3%
- Sucralose, aspartame, acesulfame–10%
- Erythritol, xylitol–5%
- Stevia–10%
- Monk fruit–10%
Focus–5%
Staying focused at the gym can make a huge difference in the quality of workout you receive. While there is emerging evidence on many nootropics, more research is needed on others to determine the extent of their efficacy and usefulness. Well-researched nootropics score higher than those with limited or conflicting scientific data to support claims.
- L-theanine
- Alpha GPC
- Tyrosine
- Huperzine A
- Choline bitartrate
Hydration–5%
You’ll also find electrolytes in most pre-workout products. That’s because proper hydration can positively impact workout performance and recovery efforts. We prefer products that contain the following ingredients:
- Sodium
- Potassium
- Coconut water powder
Cost per serving–5%
Recommending high-quality products that fall within a variety of budgets is something we aim to do. Because price doesn’t always reflect quality, this category carries less weight in the overall score.
We rate each product based on the following price ranges:
- Less than $1.00 per serving
- $1.00-$1.49 per serving
- $1.50-$1.99 per serving
- More than $2.00 per serving
Certifications
Companies that take the extra step to get their products third-party tested, ensuring purity, safety and quality of ingredients are recognized. Start-ups may not be able to afford the high price of third-party testing so this category carries less weight.
The certifications we look for include:
- Third-party testing
- Informed Choice (ICFS)
- NSF
- U.S. Pharmacopeia (USP)
- USDA Certified Organic
Bonus points
Bonus points may be awarded to companies that go above and beyond compared to industry standards. We think innovation and healthy competition among brands should be encouraged. Any bonus points awarded are equally weighted and may slightly improve overall product ranking.
Bonus points are given for the following:
- No proprietary blends
- Sustainable packaging
- Added antioxidants
- Organic ingredients
- Non-GMO ingredients
FAQs
Is C4 pre-workout bad for you?
C4 workout contains many well-studied ingredients, as well as some that are less understood at this point in time. It also contains several nutrient blends, a generous dose of caffeine, and artificial colors and flavors. These factors may play a role in determining if this is the right product for you and your health goals. Anyone considering adding a pre-workout supplement to their fitness regimen should consult their healthcare provider to ensure it’s the right choice.
C4 Ultimate caffeine content
C4 Ultimate Strength contains 300 mg of caffeine, a fairly standard dose for pre-workout supplements. The caffeine content may cause some users to experience restlessness, GI upset, and a racing heart. Certain individuals, such as teen athletes, pregnant and lactating women, and people with certain health conditions, are typically advised to avoid or limit caffeine intake.
Is C4 good?
There are mixed reviews on the taste of C4 Ultimate Strength. Some mention it is very sweet and prefer to add additional water to help tone down the flavor, making it more enjoyable. Despite the varied opinions on taste, many consumers agree that the product delivers on its promise of providing a strong energy boost and enhancing workout performance.
Does C4 have taurine?
C4 Ultimate Strength does not contain the amino acid taurine. Taurine may improve cognitive function, strength, and recovery, but more research is needed to know for sure. (18)
The good news is that incorporating high-taurine foods like lean meats and seafood into your diet is typically adequate in maintaining appropriate levels. (19)
Is C4 safe?
It’s important to remember that dietary supplements are not regulated by the FDA. Some ingredients may interfere with medications and certain medical conditions, so it’s best to discuss any supplement use with your healthcare provider.
However, Cellucor’s products are made in a GMP-certified facility.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any diseases.
Our experts
Pete Nastasi, CPT, CSNC
Pete Nastasi is a NASM-certified sports nutrition coach, personal trainer, and the owner of N2 Nutrition and Performance. Pete helps individual clients achieve their sports performance and weight-loss goals through a personalized approach centered around diet optimization, easy-to-follow workout routines, and healthy lifestyle habits.
Jessica Coulon
Jessica is a contributing editor and writer who specializes in fitness, health, nutrition, and science content. Previously, she was an editor for Popular Mechanics and Bicycling, where she covered pro cycling news, wrote how-to guides, and tested all the latest and greatest bike gear. She was also a regular shoe tester and contributor for Runner’s World. You can often find her skiing or riding her mountain bike, and racing with the F1RE female enduro team.
Joana Neziri, M.S., NASM CPT
Joana is a writer, editor, and content strategist focusing on nutrition, fitness, and all things health. After earning a master’s degree in business from the University of North Florida, she began a career in research and digital marketing.
Kelly Uhler
Kelly has a multifaceted background in elder care, health care, and copywriting. She has worked for organizations such as A Place For Mom and Homecare.com, which gave her the opportunity to work closely with families, providing reliable information to help them make informed decisions about their loved one’s health, safety, and quality of life.
Katie Drakeford, MA, RD, CSP, LD, CLC
Fortune Recommends Nutrition Writer
About Author
Katie Drakeford, MA, RD, CSP, LD, CLC, is a board-certified pediatric dietitian and certified lactation counselor. Katie has been a registered dietitian for more than 12 years, providing nutrition therapy to all ages across the lifespan, but found her passion in pediatrics. She has specialized in pediatric nutrition for the past 7 years.
Additionally, Katie earned her certified lactation counselor (CLC) certification. She enjoys working with parents, helping them meet their breastfeeding goals and ultimately leading to improved infant nutrition.
References
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- Samadi, M., Askarian, A., Shirvani, H., Shamsoddini, A., Shakibaee, A., Forbes, S. C., & Kaviani, M. (2022). Effects of Four Weeks of Beta-Alanine Supplementation Combined with One Week of Creatine Loading on Physical and Cognitive Performance in Military Personnel. International journal of environmental research and public health, 19(13), 7992. https://doi.org/10.3390/ijerph19137992
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