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Surprising Side Effects of Taking Energy Supplements, Says Science

Big fan of energy drinks? Like taking pre-workout before a lift? Here's what to expect.
FACT CHECKED BY Olivia Tarantino

Taking energy supplements like energy drinks, shots, or green tea pills can be par for the course for sleepy-eyed folks who need a little jolt mid-day. Instead of taking a nap, cracking open a can of a caffeine-fueled beverage, or popping a pill chock-full of energy-inducing ingredients seems to be the way many of us are going thanks to our jam-packed lifestyles. In fact, energy drinks are now the fastest-growing product in the beverage industry, highlighting just how many people are jumping on this vitality bandwagon.

Most items toted as "energy-boosting" contain caffeine, a stimulant that is naturally found in your beloved cup of coffee or tea. Yet, energy supplements often contain levels of this stimulant in quantities that are far greater than what you find in a regular cup of joe. Plus, these items may contain other "boosters" like B vitamins and certain herbal extracts.

And while taking energy supplements may appear to be harmless, there are some effects that you may find if you include them in your day—especially if you are taking them regularly and in large quantities.

Here are six side effects of taking energy supplements, according to science. Read on, and for more on how to eat healthily, don't miss 7 Healthiest Foods to Eat Right Now.

You may have more energy.

supplement pills for healthy living strong hair energy

OK – this one may not be that surprising. Energy supplements will likely make you feel like you have more energy. Most people will feel this effect of taking energy drinks within 30 minutes. Some may feel a slight spring in their step when they take them, while others may feel like they are bouncing off the walls. The outcomes can vary based on many factors, including which ingredients are found in the supplement, how much caffeine is included, and how your body metabolizes these ingredients.

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You may feel jittery.

iced coffee

Caffeine can stimulate your adrenaline and may cause your heart rate to increase, which may leave you feeling the jitters, especially if you took in too much at a time. If you are feeling this pesky side-effect, try drinking some water or participating in some exercise to calm this feeling. Read more: What Happens To Your Body on Energy Drinks, Says Science.

Men may experience fertility challenges.

energy drink

If a man is trying to conceive, he may experience challenges in the baby-creating department if he takes too many energy supplements, particularly energy drinks. Caffeine intake is associated with reduced total sperm count and drinking energy drinks is linked to a reduced likelihood of achieving pregnancy within one cycle. And in one study published in Reproduction Toxicology, results show that drinking as little as one energy drink serving per day may result in this negative effect.

You may have trouble sleeping.

energy supplements

Yes, energy supplements can help keep you awake during the day. But they may have the same perky effect on your body once the sun goes down.

Depending on how your body metabolizes the ingredients and what time of the day you gave yourself a boost, you may experience trouble sleeping if you partake in energy supplements—especially close to bedtime. Not getting adequate sleep could make you feel sleepy during the day, which could make you want to take energy supplements, which could then cause insomnia at night—wash, rinse, repeat. On the other hand, for better sleep, don't miss The #1 Best Thing to Eat for Better Sleep, Says a Dietitian.

You may experience improved endurance performance.

man making protein shake

Athletes tend to lean on energy supplements thanks to a slew of claims made by the brands. While some of the assertions linked to these supplements are yet to be proven, data does suggest that energy supplements, specifically energy drinks, have been found to improve endurance performance. Unfortunately, the same level of data does not yet exist for claims surrounding energy drink intake and muscle strength and power improvement.

You may experience alcohol intoxication or toxicity.

studying energy drinks

If you are taking energy supplements with alcohol thinking that the stimulation from the caffeine will balance out the sedative effect of the booze, then think again. While many falsely believe that will prevent the drowsiness and sleepiness from alcohol and allow the person to consume more alcohol, unfortunately, this combo can lead to alcohol toxicity. Plus, combining both energy supplements and alcohol is linked to an increased risk of participating in risky behavior.

Your best bet is to avoid combining alcohol and energy supplements altogether. Check out Side Effects of Giving Up Alcohol, According to Science.

Lauren Manaker, MS, RDN, LD, CLEC, CPT
Lauren Manaker is an award-winning registered dietitian, book author, and recipe developer who has been in practice for almost 20 years. Read more about Lauren