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Pre Workout Supplements


A new year brings a fresh start and is a good time to reboot and improve our lives with resolutions. Who hasn’t made a New Year’s resolution to lose weight and get in shape? The desire to get rid of the dreaded “muffin top” or “Dad-bod” is often achieved by joining a fitness center. Gyms across the state, from Kansas City to St. Louis and Columbia to Springfield welcome new members with extra incentives to lose weight. For many people, a new work-out routine also involves using pre-workout supplements to “boost” the exercise session. These supplements are advertised to increase energy, motivation, performance and strength in hopes to reduce body fat and promote muscle growth.

Pre-workout supplements are similar to medications because they can alter the body and may cause unwanted side effects, but unlike medications, supplements are not regulated by the FDA. The Missouri Poison Center is often asked, “Are supplements safe?”. The answer is somewhat complicated. The “supplement facts panel” located on the back of the bottle is intended to provide transparency and information to the consumer, but sometimes the long list of impressive sounding ingredients can be deceiving. You will often find the phrase “proprietary blend” on the label. This blend may contain the list of individual ingredients but the amount or dosage of each ingredient is NOT usually provided. Because the dosage is unknown, it is difficult to know if there is enough of an ingredient to provide any benefit or too much of an ingredient that could cause harm. Supplements are also notorious for containing ingredients that are not included on the label.

The brands of pre-workout supplements are almost endless between online sources, specialty supplement shops, and even grocery stores or pharmacies. While each supplement provides their own secret blend of ingredients, you will find some common ingredients that many of the brands share.

Some common ingredients found in pre workout supplements are:


Caffeine is a well-known chemical present in coffee, soft drinks and energy drinks. It is added to supplements to increase alertness and athletic performance. The amount of caffeine in the supplement is usually far more than a cup of coffee or a soft drink. This can lead to nervousness, irritability and insomnia, keeping you from getting to sleep (especially if taken in the evening). Caffeine can also increase the heart rate and blood pressure. If you have high blood pressure, it is best to stay away from any pre-workout supplements that have a stimulant (like caffeine). Caffeine is also a diuretic (increases urination) which can lead to dehydration after a workout if there has not been adequate hydration before, during and after the exercise.


Beta-alanine is claimed to improve endurance and cardiovascular performance while reducing muscle fatigue. It can cause a tingly or prickly sensation throughout the body. Some manufacturers specifically add beta-alanine into the supplement to produce the tingly sensation and give the user the “feeling” that it is working. This sensation typically goes away the more you use a product and is not known to cause any harm but is a nuisance for some users.


Niacin is also called vitamin B3 or nicotinic acid. It’s benefit in supplements is unclear. It often causes a side effect of flushing or reddening of the skin along with minor swelling, commonly referred to as the “niacin flush”. The effects do not last long and are not harmful. Along with the redness comes a tingling sensation similar to that felt with beta-alanine which makes the user feel like the supplement is kicking in and working.

Citrulline Malate:

Citrulline is an amino acid that is bound with malic acid to make citrulline malate. It is a vasodilator, which means it helps expand the blood vessels throughout the body, allowing for better blood flow. It is claimed to enhance athletic performance and relieve muscle soreness. Dilated blood vessels can cause headaches, especially if the user is dehydrated. If you experience headaches, it might help to decrease the serving size of the supplement and stay well hydrated before and after taking the supplement.


Yohimbe is also a vasodilator which claims to help to improve blood flow and provides the body with increased oxygen flow. It is often added to help shed stubborn body fat and promote weight loss. These effects have not been proven. It can also lead to headaches as described with citrulline malate and may have a laxative effect which can cause stomach discomfort and diarrhea. If this happens, it may help to mix the powder with more water than is recommended. A less pasty consistency of the supplement will cause less irritation to the gut and should help decrease or eliminate the diarrhea. If diarrhea persists, stop taking the supplement.

Ultimately, it is up to the individual using a pre-workout supplement to weigh the risks vs. benefits. Always consult with your physician before starting an exercise program, and certainly before using any supplement. Stay hydrated before, during and after your workout. Listen to your body, if you develop a racing heart, feel weak or faint, experience pain or get overheated, stop the exercise, cool off, and drink fluids. If symptoms are not improving, seek medical attention.

If you have experienced an adverse event after taking a pre-workout supplement, there is a Safety Reporting Portal which reports the incident to the Food & Drug Administration (FDA) and the National Institutes of Health (NIH). Reporting can be done by the manufacturer, a health care professional, public health official or a concerned citizen.

Call the Poison Help line to receive free, fast, and confidential poison information by calling one of our specially trained nurses and pharmacists at: 1-800-222-1222.

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