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7 Pre-workout Ingredients to Avoid And Why

Connor Sellers
Published by Connor Sellers
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: September 26, 2022
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Being in the fitness industry for such a long time, I often get my hands on pre-workout formulas with highly questionable supplement-fact panels.

While it’s difficult to recommend the best pre-workout (since it depends on preferences), it’s not hard to tell what formulas to avoid, thanks to their shady ingredients list.

To help my clients and readers steer clear of questionable pre-workout supplements, I decided to team up with my nutritionist and a doctor to conduct an extensive study of unwanted ingredients in popular formulas on the market.

Here are our findings.

Quick Summary

  • Ingredients you should probably avoid in formulas include Yohimbe, DMAA, p-Synephrine, Amnioisophetan, fillers, and artificial sweeteners and colors.
  • You should also avoid products that contain proprietary blends, inadequate ingredient doses, or high caffeine or other stimulants.
  • A formula should contain ingredients like Caffeine, L-citrulline, Beta-alanine, Creatine, and BCAA.

What Ingredients Should You Avoid in Pre-workout?

Close up shot of a scoop of pre-workout powder

Ingredients you should avoid in pre-workout are those with purported impressive and potent effects that, under the surface, carry a risk of unpredictable side effects due to the lack of scientific evidence and testing.

Those pre-workout ingredients primarily refer to Yohimbe, DMAA, p-Synephrine, and Aminoisophetan.

Let’s get into more detail.


Yohimbe made its way to many formulas because some evidence suggests it may increase blood flow and aid in fat loss [1].

In traditional medicine, this ingredient extracted from African evergreen tree bark is used for erectile dysfunction treatment in recommended doses ranging from 5.4 to 10 milligrams three times daily [2].

In excess doses, Yohimbe might induce side effects like anxiety, hypertension, and tachycardia - but it’s still part of proprietary blends where the exact ingredients or the amount is unknown [3].

Related: Does Yohimbe as a Pre-Workout Work?


DMAA is an FDA-banned substance known under the names of 1,3 - dimethylamylamine, methylhexanamine, or geranium extract, and it definitely earned its place among the pre-workout ingredients to avoid.

According to the FDA, ‘DMAA can raise blood pressure and lead to cardiovascular problems ranging from shortness of breath and tightening in your chest to heart attack’ [4].

Although it increases blood pressure and heart rate, several companies somehow still manage to make DMAA pre-workout because of its ability to boost performance and exercise capacity.


P-Synephrine graphic with a workout bottle and weights in the background

An ingredient called p-Synephrine, also known as Synephrine, Bitter orange peel, or Citrus aurantium, is used as a substitute for banned Ephedrine due to its similarities with this banned substance.

Since it can affect muscle endurance, especially combined with caffeine, you can see it on some pre-workout ingredient labels or even fat-burners formulas, as it may also impact fat oxidation [5].

Some potential side effects include migraines, nausea, dizziness, and hypertension.

According to the National Center for Complementary and Integrative Health, ‘there is currently little evidence that Bitter orange is safer to use than Ephedra [6].’


Originally used as a drug for nasal congestion, DMHA (also known as Dimethylhexylamine or Octodrine) is nowadays used in pre-workouts as a central nervous system stimulant that boosts training performance, enhances weight loss, and burns fat [7].

It’s often referred to as a legal upgraded substitute for DMAA since it provokes similar effects but also suppresses appetite and improves cognitive functions.

However, it lacks evidence for safe use and may as well cause health implications similar to DMAA, like anxiety, rapid heartbeat, and high blood pressure [8].

Artificial Sweeteners and Colors

As a dietary supplement, pre-workout drinks also contain ingredients that don’t directly impact formula effectiveness but affect its palatability and desirability.

Artificial flavors and sweeteners improve supplement taste that consumers pay attention to when deciding which one to pick.

However, you should be aware that some sweeteners and artificial flavors may be harmful.

A 2012 study suggests that specific artificial sweeteners like Acesulfame-potassium, Aspartame, or Sucralose can cause issues like weight gain, bowel disease, and even leukemia [9].

Unfortunately, similar issues surround artificial food dyes, as some studies show they can impact people with ADHD [10].

For all these reasons, you should choose dietary supplements that contain natural or more tested types of artificial sweeteners or colors.

High Caffeine Contents

Coffee beans with the chemical caffeine graphic

Most pre-workout supplements contain caffeine as the central stimulant known for its proven slew of benefits - enhancing cognitive function, energy levels, and endurance [11].

How much caffeine in a pre-workout serving is too much depends on your caffeine metabolism and tolerance. Still, according to Food and Drug Administration daily limit guidelines, it shouldn’t exceed 400 mg [12]. It’s the amount equal to four to five cups of coffee.

Despite the guidelines, some supplement companies surpass this limit and put too much caffeine to boost your performance at the expense of your health, risking unwelcome side effects that include anxiety, jitters, insomnia, high blood pressure, etc. [13].

To stay in a safe zone, opt for those that have doses within the range of daily recommendations or you can try caffeine-free pre-workouts.


The tactic many obscure brands use to deceive consumers is to use substantial amounts of ineffective and needless ingredients to maximize the portion without much investment. This creates a misguided assumption that the product is good due to its ingredient quantity.

Those additives are often cheap and ineffective, like maltodextrin (a cheap carbohydrate) that has zero nutritional value and may even lead to inflammation and digestive issues.

They also bump up more caffeine for similar reasons. As mentioned earlier, this might seem impressive, but in reality, excessive amounts bring more harm than good.

Other Things You Should Avoid

A woman mixing preworkout

Another thing you should avoid when choosing the right pre-workout is the unknown or ineffective dosage of ingredients.

Let’s get into this.

Proprietary Blends

A proprietary blend is a mix where all the ingredients the supplement contains are lumped into one, so you don’t know the exact dosage of each component in the product.

A survey conducted in 2019 showed that half of the top 100 pre-workout supplements have a proprietary blend [14]. The reason behind this lies in supplement companies’ efforts to hide the under-dosed ingredients to cut production costs and boost margins.

For companies, it’s not obligatory to show actual ingredients dosage because the blend is specific to the manufacturer’s product. The FDA only requires blends to be labeled with total weight and the ingredients sorted in descending order by weight.

Nevertheless, proprietary blends are one of the biggest gimmicks in the supplement industry, with doses of often unnecessary ingredients that could be potentially dangerous or ineffective, in the least.

Inadequate Ingredients Doses

In the era where online and clinical studies are accessible to everyone, it’s quite an easy task to choose a product that contains clinically effective dosages of ingredients, as anything else would be a waste of money.

Therefore, always opt for formulas that have scientifically-proven pre-workout ingredients in adequate amounts to get the most out of the product.

What Ingredients Should You Look For?

Close up shot of pre-workout powder

Ingredients you should look for in a pre-workout are:

  • Beta-alanine
  • Creatine Monohydrate
  • Caffeine
  • L-citrulline
  • BCAA (Branched-chain amino acids)

All these ingredients have scientifically proven benefits a good pre-workout should provide, and it’s no wonder they are always part of renowned brands’ formulas.

Beta-alanine is in a pre-workout as an amino acid that might increase muscular endurance and reduce fatigue with effective dosages ranging from 2-5 grams daily [15].

Creatine monohydrate is one of the most tested and safest supplements in recommended daily dosages of 3-5 grams.

It is a substance used primarily for increasing muscle mass, but it found its role in pre-workouts since it can also boost strength and exercise performance [16].

“With creatine, not only has it built a solid reputation among lifters and many other types of athletes, but the science backing it as a legit performance enhancer is robust and pretty consistent. With over 2,000 studies, it’s the most effective performance-boosting supplement out there.”

- Douglas Kalman, PhD., RD

Aforementioned, caffeine is a widely-known substance for enhancing physical and cognitive performance.

It is used in almost every pre-workout supplement as it stimulates the central nervous system, increasing endurance and strength [17].

L-citrulline is an amino acid that can increase blood flow and widen blood vessels affecting the pump during the workout [18]. L-citrulline effective doses range from 3 to 10 grams [19].

Finally, BCAAs are three essential amino acids that play a part in blood sugar regulation and muscle soreness relief and therefore are often constituents of good pre-workouts [20].

What Benefits do Pre-workouts Provide?

A person in the gym lifting weights

Pre-workouts provide benefits like high energy levels, better blood flow, and improved alertness and concentration that can synergistically push you through challenging exercises.

Consistent intake in moderate doses can help some of the ingredients like creatine steadily build up in your body, so after a few weeks, you may feel less tired during and after workouts.

Also, if you compare pre-workouts vs energy drinks, these formulas have specific ingredients designed to get you through your training and usually don’t contain empty calories.

Nonetheless, if you have any underlying health condition or take any medicine, you should first consult with your doctor before taking any stimulant product.


What Is The Most Effective Ingredient in a Pre-workout?

The most effective ingredient in a pre-workout is caffeine. Proper caffeine intake can improve your overall performance, keep you focused, and give you energy - the essential benefits a formula should provide.

Usually, formulas contain caffeine doses ranging from 150-300 mg per serving, equal to three cups of coffee.

What Ingredients in Pre-workout Make You Crash?

An ingredient in pre-workout that makes you crash is caffeine.

High doses of caffeine cause profound inhibition of adenosine (a substance responsible for energy transfer inside the body), leading to improved energy, performance, and focus.

However, when caffeine starts to fade, previously inhibited adenosine starts overflowing and causes sudden tiredness, irritability, and inability to concentrate.

How To Choose The Proper Pre-workout

After reading these guidelines, choosing the proper product shouldn’t be challenging. The most important thing is to know which pre-workout ingredients to avoid and which ones the product should contain so you can get the best bang for your buck.

To save you some time, we tested and made a list of the most effective formulas on the market currently:

Make sure to check out our guides and find the product that suits you the best.


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