Cellucor C4 Ultimate pre-workout review

Cellucor C4 Ultimate is considered the premium and ‘strongest’ pre-workout available from Cellucor.

At a first glance at the ingredients list, you will probably see that it looks more advanced than the previous supplements of this variety from the manufacturer. But how does it perform?

In this review, I will take an in-depth look at this product and share my experience after taking it. I will also compare it to my previous experience with other pre-workout supplements in the C4 range so you can find out if it is worth its higher price tag.

C4 Ultimate container


In the manufactures marketing material, they break down the ingredients into 4 groups. These are:

  • Energy – Caffeine, theacrine, and a tiny dose of a West African shrub
  • Performance – Beta-alanine and 2 types of creatine
  • Pumps – A mixture of 3 citrulline varieties
  • Focus – 4 ingredients that are shown to help mental performance

C4 Ultimate ingredients

Here are my thoughts on the ingredients in detail:

Caffeine – 300mg

There is a large amount of caffeine anhydrous per serving. The included amount of 300mg is around the equivalent of 2 cups of coffee. This should scare off any newbies to pre-workouts or those with a low caffeine tolerance straight away.

caffeine formula

Whilst this isn’t the highest amount of caffeine in a pre-workout on the market, it definitely more than average. It is also getting close to the 400mg daily intake recommended by the FDA.

Here is the caffeine content compared to other Cellucor products:

Pre-Workout Caffeine Per Serving
C4 Ultimate 300mg
C4 Original 150mg
C4 Sport 135mg
C4 Ripped 150mg
C4 Ripped Sport 135mg
C4 Ultimate Shred 300mg
C4 Extreme 200mg
C4 Dynasty 350mg

A chart comparing the caffeine content per serving across Cellucor C4 supplements is below:

C4 pre-workout caffeine chart

Theacrine – 62.5mg

This is a naturally occurring caffeine that is said to be less toxic than regular caffeine. The inclusion of this ingredient is probably there to add an even more stimulating effect without going over the top with the caffeine amount.

Rauwolfia Vomitoria – 1mg

This is a West African shrub that has therapeutic uses. It is used in medicine as a sedative, tranquilizer, stimulant, and for the treatment of anxiety. There isn’t much scientific research backing the use of this substance for sports performance.

C4 Ultimate close up

The inconsistency of this ingredient and the fact that such a small amount has been added, makes me believe that it is there just to make the ingredients list more impressive.

Beta-alanine – 3.2g

This is a naturally occurring substance that reduces lactic acid build-up in the muscles. This ingredient is common in pre-workouts and it is one of the main ones responsible for improving muscular endurance and helps to push out a few extra reps.

A high amount of CarnoSyn beta-alanine has been included per serving which is around double that of most pre-workouts. This resulted in a substantial amount of skin-tingling sensation for me.

Here is the beta-alanine content compared to other Cellucor products:

Pre-Workout Beta-Alanine Per Serving
C4 Ultimate 3.2g
C4 Original 1.6g
C4 Sport 1.0g
C4 Ripped 1.6g
C4 Ultimate Shred 3.2g
C4 Extreme 2g
C4 Dynasty 6.4g

Creatine – 2g

The creatine in this supplement is a mixture containing 1g of creatine nitrate (just like in C4 Original) and 1g of creatine HCL which is a patented version by CON-CRET. This is marketed as the #1 bioavailable creatine.

creatine formula

A study found that Creatine HCL is 38 times more soluble than creatine monohydrate. So the assumption can be made that is absorbed better by the intestines although there are no human studies on this form of creatine yet.

Here is the creatine content compared to other Cellucor products:

Pre-Workout Creatine Per Serving
C4 Ultimate 2g (Hydrochloride & Nitrate)
C4 Original 1g (Nitrate)
C4 Sport 3g (Monohydrate)
C4 Extreme 1g (Nitrate)
C4 Dynasty 5g (Monohydrate, Hydrochloride & Nitrate)

Citrulline Complex – 6g

The mixture of the non-essential amino acid citrulline in various forms. It boosts nitric oxide levels in the body and therefore enhanced blood low and muscle pumps. There is 4g of l-citrulline which is a common additive in pre-workouts.

But there is also 1g of citrulline malate which is a combination of l-citrulline and malic acid. This is believed to have a better absorption rate and bioavailability than plain old l-citrulline. So the question is why wouldn’t the manufacturer just use citrulline malate instead of l-citrulline?

C4 Ultimate container top view

I personally believe that this is to make the ingredients listing appear more impressive to the consumer and perhaps to save on cost. The same goes for the added 1g of citrulline nitrate in the mixture which is another more efficient form of l-citrulline.

Taurine – 1g

While it is an essential amino acid, Taurine is also well-known in the fitness community to offer many performance benefits. Studies have shown that it can improve anaerobic performance, VO2 max and reduce muscle damage.

But 1g of Taurine is a low dose for improved physical performance. There are mental benefits from taking a low dose like this but there is not a lot of scientific research to back it up.

N-Acetyl L-Tyrosine – 400mg

Studies show that L-tyrosine has an improvement on brain function including memory and mental focus at 500mg to 2000mg. So while this is slightly below the recommended amount, it should provide some benefit.

Alpha GPC – 200mg

This is a nootropic that improves focus and cognitive performance. The AlphaSize brand of Alpha GPC brand is used as an ingredient. I have taken this myself and can confirm that it works. One study also suggests that it can increase power output when taken before exercise at a higher dose.

Huperzine A – 50mcg

Studies suggest that huperzine A can improve memory and may be a useful treatment for Alzheimer’s. However, there isn’t a lot of evidence of its benefits in sports performance.

Dosage & Servings

A single serving scoop is 16g. That’s quite a lot bigger than other pre-workout supplements. In comparison, C4 Original has a serving size of 6.5g which shows just how much more is in C4 Ultimate.

C4 Ultimate benefits

This means that you won’t get as many servings per container as you would other pre-workouts. That makes this supplement dramatically more expensive to use regularly.

It takes a little longer to mix with water than other pre-workouts but it’s not overly difficult to do so. Due to the high volume of stimulants in the formula, I wouldn’t recommend taking it in the evening.

My Experience


I managed to try out all 5 flavors of C4 Ultimate. Here are my favorites:

I liked the sour taste of the Sour Batch Bros flavor the most. But if I used this pre-workout flavor every day, I think that I may get tired of the taste.

C4 Ultimate side view

Blue Raspberry is always a safe go-to for me and this tasted similar to most other ‘blue’ flavored supplements, so no complaints here. Although, I think the Blue Raspberry version of C4 Sport tasted better. The Cotton Candy flavor was similar to the Blue Raspberry but slightly sweeter with a hint of strawberry, which I was a fan of. The Cherry Limeade flavor was OK too.

My least favorites were the Strawberry Watermelon and Orange Mango flavors. While the Strawberry Watermelon tasted better than the Watermelon flavor from the C4 Original, it wasn’t as good as the other flavors. The Orange Mango flavor tasted a bit too like an artificial flavor for me.


I took C4 Ultimate before heavy weightlifting sessions. It generally took around 20 minutes for me to start feeling the effects. It started with a warm feeling on my face and a tingling sensation in my skin.

This is a normal effect of beta-alanine but the skin tingling was more pronounced than in other pre-workouts that I’ve tested, probably due to the high amount of beta-alanine in the formula.

Drinking pre-workout supplement

There is definitely an energetic feeling created by this supplement and I powered through my workouts taking it. Cellucor claims that Ultimate will provide ‘extreme focus’. While I pushed myself harder than I do usually, I feel that having this amount of caffeine and other stimulants in a serving is overkill.

I was still feeling the ‘buzz’ long after my workout and sometimes had trouble getting to sleep in the night after taking it. Therefore, I wouldn’t recommend this to people with a low tolerance to caffeine and I probably wouldn’t recommend it to beginners to pre-workout supplements.

Final Verdict

C4 Ultimate has a potent pre-workout formula that may be too strong for some people. If you are hitting the gym in the evening, you may want to give it a miss. The formula also has some unnecessary ingredients that I feel have been added merely for marketing reasons. Some of the ingredients

It has some great flavors and some that are average.

If you have a low tolerance to caffeine or have not used a pre-workout supplement before, it may be best to look for a product that is not so strong. If you are set on getting C4 Ultimate as your first pre-workout, then I would recommend starting at half serving and seeing how your body reacts to it.