Is C4 bad for cardiovascular health?

C4 is one of the most popular pre-workout supplements on the market. But is it bad for your heart? And can you take it every day?

Cardiac issues are often associated with stimulants. Pre-workouts can have high amounts of these types of ingredients. They can increase your energy for short amounts of time. But they also increase blood pressure and heart rate.

You may have heard about the cardiovascular issues caused by pre-workout supplements in the past. Many of these supplements are now banned or now have very different ingredient lists.

By the end of this article, you will have a better idea if Cellucor C4 could lead to cardiac issues.

Cellucor C4 Main Ingredients

C4 contains many ingredients commonly found in pre-workouts:


Creatine is a type of amino acid. It can be found in meat and fish and is made in your body by the liver. Creatine helps your muscles store more energy when it’s time to train. Creatine does not contribute to heart issues.

creatine powder

In fact, it may even help cardiovascular system health. In one study, the combination of weight lifting and creatine helped lower cholesterol and fat in the arteries. Studies have also been conducted on the use of creatine for patients with chronic heart failure.


Beta-alanine is the amino acid that makes up carnauba-seed oil. It increases the strength of your muscles during exercise by improving muscle endurance, which is how much muscle can be used before fatigue.

Arginine alpha-ketoglutarate

Arginine alpha-ketoglutarate is an amino acid that helps muscles release lactic acid. When you lift weights, your muscles work so hard they can become acidic. You can’t push anymore because it hurts.

Caffeine Anhydrous

This is dehydrated caffeine found naturally in coffee beans.


When you consume caffeine in a pre-workout, a small amount stays in your body longer and prolongs the effects. This is because your body absorbs only a small amount.

Vitamin C

Vitamin C is an antioxidant that supports your immune system. Studies show it can lower your risk of heart disease by preventing harmful cholesterol from building up in the arteries.

Vitamin B

Vitamin B is used in the production of energy. A lack of vitamin B can cause fatigue and achy muscles.

L-Citrulline (C4 sport version only)

L-Citrulline has been shown to improve blood flow in studies. This is done by causing a widening of the arteries which can also help to lower blood pressure.

Taurine (C4 sport version only)

Taurine is a chemical that occurs naturally in the body called amino sulfonic acid. It is mainly produced in the liver but also used in other tissues such as the pancreas, brain and testes. It has been shown to increase muscle strength. Some studies suggest that it benefits people with heart failure by reducing blood pressure.

Ingredients That Risk Heart Issues

Some pre-workout supplements can be bad for the heart with long-term use or when excessive amounts are consumed. Caffeine is the main ingredient that will affect cardiovascular health in C4. A moderate amount of caffeine (usually 4 or 5 cups of tea or coffee) is fine for most people. But caffeine does release hormones that increase blood pressure and heart rate. It can also cause the cardiac muscle to contract with more force.

Stimulants in general are considered to give potential cardiac issues. While many believe that excessive caffeine can also lead to issues, the actual studies show minimal risk. Caffeine does increase the heart rate when taken but scientists disagree on its long-term effects on the cardiovascular system.

heart rate chart

Overall, caffeine does not increase the risk of stroke or heart disease in the majority of people. However, someone with a pre-existing condition might experience problems. This risk is not for everyone. It also depends on the amount of caffeine you take, the type of stimulant (caffeine vs. ephedrine or what have you) and the person’s level of physical activity during usage.

The elevated blood pressure that caffeine consumption causes may damage the arteries over time. This can in the long term contribute to a restriction of blood flow and lead to issues in the future.

Paying attention to the amount of Caffeine and the timing that you consume is important if you already have high blood pressure.

So, the bottom line on C4 is that caffeine can have an effect on your heart. It’s not dangerous to most people but could cause issues for someone with a known condition or high blood pressure.


Other Side Effects From C4

The caffeine contained in C4 will not cause heart problems. But other side effects are common when consuming anything with a high caffeine content like this pre-workout.

Caffeine is known to cause the following side effects:

Anxiety and irritability

At higher amounts, the effects of caffeine can become more pronounced and lead to nervousness and anxiety. A high caffeine dose can cause a sudden release of adrenaline that could even lead to panic attacks.

A study found that 25 healthy men of ingested 300mg of caffeine experienced over twice the level of stress compared to those who ingested a placebo.

An increase in stress can also lead to an increase in acne from pre-workout supplements. This effect, like many others, depends on the volume consumed and your sensitivity to caffeine.


Caffeine increases alertness and blocks sleep signals from reaching the brain providing one of its most useful qualities to a lot of people. This can make it difficult to get good quality sleep.


Caffeine remains in the body for 5 hours on average which can make the effects of C4 feel like they last a long time. So if you take it late in the day, it may not allow you to sleep at all.


A rebound of fatigue can often be felt after the initial effect from caffeine wears off. One study found that individuals who consumed energy drinks felt increased alertness and mood. But they also felt more tired than usual the following day.


In conclusion, C4 is not bad for your heart. Most people do not need to be concerned about cardiovascular issues from C4. But caffeine is not recommended if you already have high blood pressure. Caffeine should be avoided by children and adolescents too, as it can interfere with their growth and is associated with depression, anxiety, and sleep issues.