C4 Vs. Amin.O Energy – Which Is Better?

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By Thomas Youngerman

Reviewed by Juliana Tamayo, MS, RDN - Last Updated

C4 Vs. Amin.O Energy

Ask me which is better, C4 or Amin.O Energy, and my initial response is that they are both good – but they’re different products with different intended uses and benefits.

Both products come from excellent sports nutrition companies: C4 from Cellucor/Nutrabolt and Amin.O Energy from Optimum Nutrition/Glanbia. Cellucor is the largest privately held business in the space, and Glanbia is the biggest sports nutrition company in the world.

C4 defined the pre-workout segment and is still the best-selling product in the category. Optimum Nutrition’s Amin.O Energy, initially an intra-workout product, is one of the company’s flagship brands and is now positioned as an “anytime energy booster” and pre-workout supplement.

We compare the products in this article, both the powdered varieties and the ready-to-drinks, providing our assessment of which is best. 

Spoiler alert: you may be surprised, as the answer depends on your reason for using the product and the benefits you seek. Our opinion of which is more appropriate may differ from powders to ready-to-drinks. Looking for a quick answer and don’t need to learn about pre-workout or intra-workout products – scroll down to the “which is better” segments below.

Before we start the head-to-head comparison of C4 vs. Amin.O Energy, let’s spend a few paragraphs defining a pre-workout versus an intra-workout product and what you can expect from each.

What Are Pre-Workouts?

Pre-workout products are dietary supplements consumed before training to provide energy, endurance, and improve performance. The NCBI, National Center for Biotechnical Information, defines these products as “multi-ingredient products (MIPS) used pre-training to enhance strength, shorten reaction time, and elicit focus.”

A typical pre-workout supplement features multiple ingredients designed to increase energy, buffer lactic acid to train longer and harder, increase strength and performance, enhance blood vessel function to improve blood flow to working muscles, and provide focus. A quality pre-workout supplement supplies more than just energy and focus – an energy drink can do that. A comprehensive pre-workout also promotes muscular endurance, stamina, vasodilation, and recovery – they aid in muscle and strength gains, having an ergogenic effect.

One key element of the pre-workout is motivation. Once you drink your pre-workout, the launch sequence has started. Knowing that enhanced energy and laser-like focus will follow, you have the discipline and motivation to hit the gym and complete a quality workout.    

What is an Intra-Workout?

An intra-workout supplement is typically designed to be consumed while working out, allowing you to train harder and longer and recover faster. Many brands include energy, hydration, and performance-enhancing components in addition to their amino acid profile. The amino acids replace essential nutrients to increase protein synthesis in the muscles, prevent the breakdown of muscle tissue, and reduce recovery time. There are two schools of thought regarding the amino acid component: BCAAs (branched-chain amino acids) or EAAs (Essential Amino Acids). Your body requires twenty different amino acids to function properly. Nine of these are considered essential since they are not produced in your body, and you must get them through diet or supplementation.

BCAAs, leucine, isoleucine, and valine are three of the nine essential amino acids and those most crucial for muscle development. Leucine, in particular, stimulates protein synthesis and supports your body by reducing the rate of protein breakdown. The accepted ratio for a BCAA is two parts leucine to one part isoleucine and one part valine (2:1:1).

More recently, companies have included the other six essential amino acids in their formulations as they contend the full spectrum works more efficiently than BCAAs alone. 

C4 vs. Amin.O Energy: The Powders

As indicated in our opening, our opinion of which brand is best depends on what you want to accomplish with your supplement and which form of C4 or Amin.O Energy you are considering, powdered or ready-to-drink (cans).

We start our comparison with the powdered format. In both instances, the powdered varieties were introduced first and led to ready-to-drink line extensions only after the brands were firmly established. You’ll notice that the formulas in the powders are more elaborate and that the RTDs are simpler versions designed to capture a share of the vast energy drink category in convenience stores, specialty shops, and big box retailers.  

C4 Original Pre-workout Powder

Although Dan Duchaine’s Ultimate Orange was the first pre-workout powder, C4 was an early pioneer, and today is the number one selling brand globally. What began as C4 Original, with a limited number of flavors, is today a complete product line with 87 different flavors and variations, from Original to Sport, Ultimate, Extreme, Ready-to-drinks, and so on. 

Cellucor C4 Supplement

C4 Original is a powdered dietary pre-workout supplement formulated with four vitamins, each at more than 100% of the recommended DV, an energy/focus blend including 150 mg of caffeine and TeaCrine, and three ergogenic components for strength, endurance, and muscle pumps. 

  • CarnoSyn Beta-alanine, 1.6 grams, for enhanced endurance and power output during your workout by buffering lactic acid
  • NO 3 T Creatine Nitrate, 1 gram, combines the benefits of creatine and nitrates for strength, vasodilation, and muscle pumps. 
  • Citrulline Malate, 1 gram, is a precursor to nitric oxide (NO) for vasodilation, improving blood flow to the muscles. 

All Cellucor products are made in GMP-compliant facilities, and C4 Sport products are also certified as Safe for Sport by third-party NSF.  

Those seeking a more natural product should know that C4 Original uses artificial sweeteners, sucralose, acesulfame potassium, and artificial coloring, FD&C Blue #1.

Dosage & How to Take C4 Original                                                                    

Take one serving (1 level scoop, 6 grams) of C4 Original with six fluid ounces of water about 20-30 minutes before training. The company notes some users may experience a “harmless” tingling sensation – attributable to the CarnoSyn patented beta-alanine.  

Essential Amin.O Energy Powder

Ironically, the first major intra-workout brand was Xtend BCAA powder, now owned by Cellucor/Nutrabolt. Essential Amin.O Energy is a leading brand for Optimum Nutrition, available in fifteen varieties of powder and nine ready-to-drinks, including line extensions with added Electrolytes and UC II Collagen. 

essential amin.o energy

Amin.O Energy is a powdered dietary supplement featuring an energy component, caffeine, green tea leaf, and green coffee bean at 160 milligrams, a small amount of sodium (less than 1% of the daily value), and a 5-gram blend of micronized amino acids, containing fourteen different aminos for muscle recovery. The company positions Amin.O Energy as supporting energy, focus, and muscle. 

The amino acid blend contains eight of the nine “essential amino acids” (highlighted), including all three BCAAs. 

  • Leucine
  • Isoleucine
  • Valine
  • Histidine
  • Lysine
  • Phenylalanine
  • Threonine
  • Methionine
  • Taurine
  • Glutamine
  • Arginine
  • Beta-Alanine
  • Citrulline
  • Tyrosine 

Other amino acids of note in the blend are Glutamine – great for gut health, aids in recovery, and addresses training-induced muscle soreness. Arginine and citrulline are converted to nitric oxide in the body for vasodilation. Beta-alanine helps to buffer lactic acid. Given that the blend is 5 grams in total, these aminos would be severely underdosed compared to the effective recommended dosages.

Considered initially an intra-workout product, the company now features Amin.O Energy as applicable before training along with its more pre-workout dedicated product, Gold Standard PRE Advanced. Note: PRE Advanced contains a much higher dose of caffeine, 300 mg, and although Amin.O Energy contains beta-alanine and citrulline, as noted above, PRE contains a full 6 grams of citrulline and 3.2 grams of beta-alanine. 

All Optimum Nutrition products are manufactured in cGMP (Good Manufacturing Practices), Informed Sport, and Informed Choice registered facilities. Like C4, Amin.O Energy uses natural and artificial sweeteners, flavoring, and coloring. 

Dosage & How to Take Amin.O Energy Powder  

In another bit of irony, the company recommends taking Amin.O Energy pre- or post-workout but doesn’t mention intra-workout.

“Consume one or more servings first thing in the morning and/or between meals. For pre-workout energy: take 1-3 servings 20-30 minutes before training. For post workout recovery: Take 1-2 servings immediately after training”.  Note: the serving size is 9 grams, about two scoops.

C4 vs. Amin.O Energy: Which Powder is Better?

Typically, when comparing supplements, we consider the following:

  • The companies’ practices, such as cGMP compliance and third-party testing. Cellucor and Optimum both get excellent marks.
  • Products that contain patented, trademarked ingredients, with clinical studies to validate their structure/function claims – at the appropriate dosages. C4 contains three patented compounds; however, CarnoSyn and TeaCrine are at somewhat lower doses than recommended or used in clinical trials.
  • Transparency in labeling – both products use proprietary blends, Amin.O Energy in its Amino Blend and C4 in its Energy/Focus Blend.
  • Products certified by USP, NSF, or Safe for Sport – both products qualify.

Other considerations include:

  • Price – as the Price Comparison below shows, neither product has a distinct advantage. 
  • Accessibility – both products employ omni-marketing strategies, with the products broadly available online and in stores.
  • Convenience – Cellucor holds a slight edge here, with one scoop representing a serving versus two scoops for Amin.O Energy – not a significant issue or advantage. 
  • Taste – Amin.O Energy has more flavors, eleven, versus C4’s nine varieties. No advantage as there are ample options for everyone’s taste. 

As you can see from the above, our standard criteria fail us in this comparison. Both are good products from highly respected companies, following best-in-class practices. 

So, which is right for you? It all depends on what you are seeking in these products. 

Essential Amin.O Energy may be right for you if you want a gentle energy drink to supplement your amino acid intake across a broad spectrum. The 160 milligrams of caffeine in Amin.O Energy equates to about a cup and a half of coffee. You will benefit from muscle recovery but don’t expect Amin.O Energy to majorly contribute to muscle-building, increasing stamina, or vasodilation for muscle pumps.  

If you want a product with a modest energy component that will provide focus, enhance strength and performance, increase vasodilation for blood vessel function, and help reduce muscle fatigue, a dedicated pre-workout supplement, like C4, is the better option. 

To optimize your supplement regimen, we recommend a pre-workout product, such as C4 Original, and an intra- or post-workout, such as Amin.O Energy.

Note: there are better options than C4 Original as a pre-workout, (even within the C4 brand) with more effective ingredients at efficacious dosages, and we’d prefer at least 6 grams of BCAAs in your intra- or post-workout. 

C4 vs. Amin.O Energy: Ready-to-Drink Cans

If powders are designed for the performance-oriented user, ready-to-drinks target the energy crowd.

For good reason, the global energy drink business was more than $91 billion in 2022, nearly four times the size of the pre-workout category. Although C4 and Amin.O Energy powders enjoy broad distribution in specialty shops, online, and even the big box stores, ready-to-drinks live there and in C-stores, gyms, and virtually any retailer with a refrigerated section. 

Ready-to-drinks are also classified differently than powdered supplements.  Pre-made drinks, i.e., our ready-to-drinks, are regulated by the FDA as beverages, not supplements, and there are different beverage regulations. You’ll notice that the C4 and Amin.O Energy RTDs have a Nutrition Facts label, not a Supplements Facts panel. 

A Nutrition label tells us Calories per serving, Total Fat, Total Carbs, Sugar, and Total Protein, with a separate ingredients list. The dosage of the ingredients is not stated. A Supplement Facts panel also lists the macronutrients plus the other compounds in descending order, listing each dosage – except in a proprietary blend. 

C4 Carbonated

C4 Carbonated is a “performance” energy drink.

c4 smart energy

The Nutrition Facts label doesn’t tell us much; each 12-ounce serving provides five calories but zero Fat, Sodium, Carbs, Sugar, and Protein. The label does show us Potassium, Niacin, and Vitamin B12.

Other ingredients are listed in descending order by volume, starting with carbonated water. CarnoSyn Beta Alanine (detailed in the powder segment above) is next, followed by L-Citrulline, Malic Acid, Betaine Anhydrous, Caffeine (200 mg), Sucralose, and N-Acetyl-L-Tyrosine.

Note: there is no NO 3 T Creatine Nitrate in C4 Carbonated, the strength and nitric oxide component in the powder. Until recently, it has been difficult, if not impossible, to make creatine effective in an RTD. 

Betaine Anhydrous substitutes for the NO 3 T in C4 Carbonated, and N-Acetyl-L-Tyrosine replaces the TeaCrine for focus.

The company advertises “explosive energy” (notice the RTD has more caffeine than the powder), less muscle fatigue, and increased endurance, attributable to CarnoSyn. C4 is NSF-certified Safe for Sport – free of any banned substances.                                                                                                                                                                

Amin.O Energy + Electrolytes Sparkling

The Optimum Nutrition entry into the energy market is Amin.O Energy + Electrolytes, for anytime energy and hydration.

Each 12-ounce can, available in nine different fruit flavors, delivers the same 5 grams of amino acids; however, only eight aminos are in the blend. Three essential aminos are present, versus eight in the powder, and Leucine is the sole BCAA in the formula. 

Like C4, the Nutrition Facts panel indicates only five calories per serving, with zero Fat, one Carbohydrate, no Sugar, and no Protein. After carbonated water, the amino blend is the next component listed in the ingredient panel.

Amin.O Energy delivers 100 mg of caffeine from natural sources, coffee beans or tea leaves. The electrolyte/hydration component is comprised of minerals like potassium, sodium, and magnesium, which help support fluid balance and muscle function. 

Although the Optimum manufacturing facilities are Informed Sport and Informed Choice registered, we do not know if the specific product is certified. 

So, Which RTD is Better?

We reviewed corporate practices in the powder discussion, and the same data applies regarding GMP facilities, third-party testing and certifications, label transparency, and trademarked ingredients. C4 Carbonated uses CarnoSyn (Beta-Alanine) and BetaPower (Betaine Anhydrous), while Amin.O Energy uses Sustamine (a combination of L-glutamine and L-Alanine). 

Amin.O Energy uses caffeine from natural sources compared to C4’s caffeine anhydrous. Some consider anhydrous a purer and more potent form of caffeine, while others contend naturally sourced is gentler on your body. For the naturalists, both products contain natural and artificial flavors and sweeteners, including sucralose. 

essential amin.o energy bottle

As to accessibility and convenience, both products enjoy broad distribution and are available online and in stores – Optimum even mentions its single cans are available at most 7-11 stores on its website. Both products are pre-made, ready to drink, and in 12-ounce cans. 

Once again, price is not a major consideration as the two brands are priced similarly for their RTD offerings. With eight flavors of C4 Carbonated, not to mention the other thirty varieties of C4 RTDs, and nine flavors of Amin.O Energy + Electrolytes, we’re sure you can find one to suit your taste.

So, which is better? In this instance, considering where and when you might buy an RTD, Amin.O Energy + Electrolytes is the clear winner.

In addition to the benefit of electrolytes for hydration in the Optimum product, the best times to supplement with amino acids are between meals and following a workout. Yes, the Cellucor product may contain more caffeine, but the 100 mg in Amin.O Energy will give you a nice gentle boost. Unless you’re heading directly to the gym, the performance ingredients in Cellucor aren’t really necessary. 

Now, as promised, let’s look at pricing:

C4 vs. Amin.O Energy: Price Comparison

C4 Original Pre-workout Powder

The 6.1-ounce, 30-serving container retails for $29.99 on the website. With a subscription (monthly auto-ship), the price is $20.99, and shipping is free. The one-time purchase price equates to $1.00 per serving.

Cellucor C4 Website

The same 30-serving C4 Original is $29.50 at, and they also offer subscription savings. Pricing is $34.99 at specialty retailers such as GNC and Vitamin Shoppe.

C4 Carbonated

A twelve-pack of 16-ounce C4 Carbonated in cans retails for $27.99 on the website – the cost per serving is $2.33.

C4 Non-Carbonated 

The non-carbonated version is 12 ounces per serving and comes in a bottle versus a can. A case of twelve sells for $29.99 on the company website or $2.50 per serving. 

Amin.O Energy Powder

A 9.5-ounce, 30-serving container retails for $27.99 on the company website, $.93 per serving. There are additional quantity discounts, yet we did not see a subscription service offered. 

essential amin.o energy website

The same product sells for $24.98 on, $26.99 at Vitamin Shoppe, and $29.99 at GNC. 

Amin.O Energy + Electrolytes Sparkling

A twelve-pack of 12-ounce cans sells for $29.88 on the company website or $2.50 per serving. 

In Summary: C4 vs. Amin.O Energy

Where, when you are buying the product, and the benefits you seek were key considerations in our analysis. Optimum Nutrition and Cellucor are highly respected in the natural products space, and the products reviewed are viable options. As indicated in our opening, our preferences differed by delivery format, powder versus pre-made. That said, more comprehensive and potent pre-workout and intra-workout products are available for the more hardcore athlete. 

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Thomas Youngerman

Thomas Youngerman is an entrepreneur and author in the health and wellness space with extensive experience in the supplement industry. He has owned multiple sports nutrition stores and served as the Category Manager and Director of Business Development for a regional chain of nutrition stores. Thomas created a successful line of men’s healthy aging supplements that was distributed in GNC, The Vitamin Shoppe, and Kroger, and later sold to a West Coast corporation. Thomas was previously a certified nutrition coach. He has a strong understanding of nutrition, supplement formulations, DSHEA, cGMP, and FDA regulations.