JYM Supplement Science


Pre-Workout Powder Powerhouse Packed with 13-Hand Picked Ingredients to Support Improved Workouts*
A Cutting-Edge Pre-Workout Formula Built on Solid Science*
9.1  out of 10  (3,922 Reviews)

Product Overview

JYM Pre Jym.

"Welcome to my latest creation, JYM Supplement Science. JYM combines real science with real ingredients to deliver unreal results. Pre JYM, my cutting-edge pre-workout product, has revolutionized the pre-workout category."

Supplement companies love to claim they've created a real “game-changer.” Pre JYM doesn't play that game. It doesn't need hype or flashy marketing. With 13 hand-picked ingredients included at full amounts, Pre JYM is in a league of its own.

Put simply, Pre JYM is the most effective pre-workout supplement I've ever developed. It's built on solid science and decades of professional experience. Nothing is hidden, and there is no filler. Pre JYM is research made real. It's pure pre-workout fuel."

Hit the JYM!

Jim Stoppani, PhD
Owner, JYM Supplement Science

The Power of Pre JYM
No Proprietary Blends

Look at the supplement facts panel on your favorite pre-workout product and you'll most likely see the term “proprietary blend.” Supplement companies want you to think this means they've created a special blend of ingredients that magically work together to deliver unique results. Because this blend is so amazing, they have to keep the amounts of each ingredient secret so no other company steals the formula.

The truth, however, is that propriety blends can serve a different purpose. They allow some supplement companies to hide how little of each ingredient they've actually put in a product. This can result in cheap, under-dosed, ineffective supplements.

Pre JYM doesn't use proprietary blends. Take a look at the supplement facts panel and you'll see the actual amounts of all 13 ingredients. I have nothing to hide. I'm proud of the amount of each and every ingredient I've included.

Proper Amounts

For the reasons detailed above, many supplement companies are moving toward transparency and axing proprietary blends. That's a good thing. However, some of these companies are still guilty of grossly under-dosing ingredients.

Take citrulline malate, for example. The research on this potent amino acid shows that you need 6 grams per serving. Most pre-workout products leave out citrulline entirely, and only a few of them provide anywhere close to 6 grams.

No "Abbreviated" Formulas

A handful of companies are as fed up as I am with proprietary blends and under-dosed formulas, but they fall short by using “abbreviated” formulas. An abbreviated formula is one that uses proper dosing of all ingredients, but only includes a few ingredients.

Take, for example, a pre-workout formula that includes beta-alanine, creatine, caffeine, and tyrosine. There's nothing wrong with it, but it could be made a lot more effective through the addition of ingredients like citrulline malate, betaine, and BCAAs, to name just a few. Why would companies not create the most robust formula possible? Because adding more ingredients costs too much money.

Pre JYM includes 13 ingredients that complement one another to prime the body for intense workouts, making it a complete pre-workout supplement. If you're looking for the most complete exercise supplement program available on the market today, take my Post JYM Active Matrix after your workout to get even greater amounts of potent ingredients like Creatine HCl, Betaine, and Beta-Alanine.

No Concentrates

Some companies also try to trick buyers by calling their pre-workout product “concentrated.” A serving of one of these “concentrated” products can contain as few as 3 to 6 grams of powder. What kind of magic did they use to cram enough creatine, beta-alanine, citrulline, arginine, caffeine, and other ingredients into that tiny serving? They didn't use any magic, which is why some of those “concentrated” formulas also include proprietary blends. That's also why the serving size of Pre JYM is more than 26 grams. It contains 13 ingredients at proper, powerful amounts.

JS, Not BS

I've been studying supplement science in the lab and gym for decades. I've been delivering supplement advice to millions of people in the pages of Muscle & Fitness, FLEX, and Muscle & Fitness Hers, as well as here on and my own website,, for over a decade.

Most importantly, I've been training since I was 11 years old. Before each of my workouts, I would draw on all of my experience and all of my education to concoct my own pre-workout supplement, combining ingredients from 13 different bottles and tubs.

That's why I developed Pre JYM. I wanted to give my friends, colleagues, all of you, and myself the ability to access, in one bottle, the best ingredients in amounts suggested to help build lean muscle, torch body fat, improve strength, and boost speed.*

Pre JYM Active Ingredients Matrix Features
  • Full amounts of 13 science-backed ingredients.
  • 6 grams of citrulline malate to help promote better muscle endurance and bigger muscle pumps.*
  • 6 grams of BCAAs in the 2:1:1 ratio for blunting muscle fatigue, boosting muscle performance, and increasing muscle growth.*
  • 2 grams of Con-Cret® Patented Creatine HCl for greater strength, endurance, and muscle growth.*
  • 2 grams of CarnoSyn® beta-alanine to boost muscle power, strength, endurance, and muscle growth.*
  • 1.5 grams of betaine for greater power and strength during workouts.*
  • 600 milligrams of N-acetyl L-cysteine to support your body's amino acid profile during exercise.*
  • 500 milligrams of Beet Root extract to enhance nitric oxide for bigger pumps and better energy.*
  • 300 milligrams of caffeine to help boost alertness and drive, increase muscle strength and endurance during workouts for greater training intensity.*
  • 150 milligrams of AlphaSize® alpha-GPC for better drive, focus, and strength in the gym.*
  • 50 micrograms of huperzine A to increase mental focus and establish a stronger mind-muscle connection.*
  • 5 milligrams of BioPerine® to enhance absorption of nutrients for even better results.*

Under the Microscope

Let's take a closer look some of the ingredients and amounts used to make Pre JYM such a pre-workout powerhouse.*

6 grams of Branched-Chain Amino Acids (BCAAs)
  • The BCAAs are three amino acids—leucine, isoleucine, and valine—that share a common structure.
  • Research suggests that leucine is the most critical because it stimulates muscle protein synthesis (i.e., muscle growth).*
  • Studies suggest the optimal ratio of leucine to isoleucine to valine in a pre-workout product is 2:1:1, exactly the ratio in Pre JYM.
6 grams of Citrulline Malate
  • In the body, citrulline is readily converted to arginine, and then to nitric oxide (NO). Research suggests that citrulline increases arginine and NO levels in the body better than arginine itself.* Arginine undergoes excessive breakdown by the intestines and liver. Studies have shown that citrulline does not, so whatever you consume is readily absorbed and put to use.*
  • Citrulline malate has also been shown to be an effective energy booster. One study reported that subjects consuming 6 grams of citrulline malate experienced an increase in ATP (energy) production during exercise and an increase in phosphocreatine recovery between bouts of exercise.*
  • Research also suggests that subjects supplementing with citrulline malate before a chest workout could complete more reps on most sets compared to subjects taking a placebo.
2 grams of Con-Cret® Patented Creatine HCl
  • There are many studies suggesting that creatine supplementation leads to significant gains in muscle strength and power, as well as muscle growth.*
  • Creatine HCl is made by attaching a hydrochloride (HCl) group to creatine.
  • Adding the hydrochloride group lowers the pH of creatine, making it more acidic. This drastically increases creatine's solubility in fluids, which may help increase its absorption and help to reduce stomach issues.*
2 grams of CarnoSyn® Beta-Alanine
  • Beta-alanine is an amino acid that gets taken up by muscle fibers and combines with the amino acid histidine to form carnosine.*
  • Research suggests that carnosine increases strength and power, improves endurance and recovery, and muscle growth.* This is increased further when taken together with creatine, as in Post JYM Active Ingredients Matrix™.
  • One study suggested that beta-alanine supplementation in boxers increased their average punching power in the last 10 seconds of a round more than those taking a placebo. Being able to maintain punching power late in the round is similar to maintaining more strength and power later in your workouts, meaning you can lift more weight for more reps.*
500 mg of Beta Vulgaris L. (Beet) Extract
  • Beet root extract is a rich source of nitrates. When you consume nitrates, they are broken down first to nitrites and then to nitric oxide (NO).
  • Beet root extract is a direct supplier of NO and uses a different pathway to produce NO than citrulline and arginine!*
  • Research suggests that nitrates can improve blood flow to working muscles and the brain.* The result is greater training intensity and endurance, and increased focus during workouts.*
  • Research has also found that nitrates can directly improve the muscle's ability to generate ATP (energy) to further improve endurance during intense exercise, such as lifting weights.*
1.5 grams of Betaine
  • Betaine, also known as trimethylglycine (TMG), is a modified version of the amino acid glycine.
  • Betaine supplementation has been suggested in studies to improve muscle strength and power production, increase the number of reps done with a given weight, and improve endurance.*
  • University of Connecticut researchers reported that supplementing with 1.25 grams of betaine twice per day for two weeks increased power and muscle force on the bench press.*
  • Betaine has also been shown to significantly increase protein synthesis following workouts as compared to a placebo. This can help lead to greater long term muscle growth.*
300mg of AlphaSize® Delivering 150mg of Alpha-Glyceryl phosphoryl choline (Alpha-GPC)
  • Alpha-glyceryl phosphoryl choline (alpha-GPC) is a naturally occurring phospholipid compound that plays a critical role in the way the brain, nervous system, and muscles function.
  • Alpha-GPC helps boost brain function and mood, improves reaction time, and helps increase focus and the mind-muscle connection during workouts.*
  • When combined with caffeine, L-tyrosine, and huperzine A (all found in Pre JYM), alpha-GPC delivers clean mental stimulation and focus that lasts throughout workouts.*
600mg of N-Acetyl L-Cysteine (NAC)
  • NAC is the amino acid cysteine with an acetyl group attached to it. Studies have suggested that the acetyl group makes it more stable and allows the body to absorb and use it better than plain cysteine.*
50mcg of Huperzine A
  • This extract from club moss is a potent brain booster that can promote better focus, enhanced memory, and elevated mood.*
  • Huperzine A helps maintain higher levels of acetylcholine, which is important for brain and muscle function.*
  • Combining it with alpha-GPC, which increases acetylcholine levels, has an additive effect, resulting in enhanced drive and focus in the gym, as well as increased muscle strength and endurance.*
300mg of Caffeine
  • Research shows that caffeine can increase muscle strength, improve muscle endurance, and decrease muscle fatigue during workouts, which allows you to take your training intensity to a higher level.*
  • Caffeine is also suggested to be a nitric oxide (NO) booster. One study in the American Journal of Cardiology reported that healthy young men taking 300 mg of caffeine experienced an increase in NO levels and an increase in blood flow to muscles.*
5 mg of BioPerine®
  • BioPerine® is a patented extract of the fruit of black pepper, or long pepper, that contains standardized amounts of the active ingredient piperine.
1.5g of Tyrosine
  • This amino acid promotes increased alertness, mental focus, mood, and energy during intense exercise, especially when combined with caffeine.*
1,000 mg of Taurine
  • Taurine is a specialized amino acid that is important for endurance and muscle strength.*
  • Exercise depletes taurine levels, thereby impairing strength and endurance, so it's critical to get a proper amount of taurine after every workout to replenish what was lost.*
JYM Supplement Science

Ratings & Reviews

Overall Rating
3,922 Ratings
Verified Buyer Rating
3,451 Ratings
Average Flavor Rating
9 Flavors
Top Rated Flavor
Pineapple Strawberry
By clicking the button above, you agree to entering the Reviews section. Products in the Store are not intended to diagnose, treat, cure, or prevent any disease.
Feb 18, 2019
Verified Buyer
  • 10 Natural Island Punch
  • 8 Orange Mango

I love this product unfortunately it made me crap my pants on the way to work after a workout. I continued trying it but continued to have URGENT bowels. I cant just sit by a toilet all day. Let me say that I did take it as jym stated. I mixed it up 15 minutes prior to starting to drink it then consumed it over 30-40 minutes. I tried with food first, I tried differant work out times from mornings to mid days with a full gut of food. To no avail. I think if you can use it without having gastro problems you'll be golden. If you get one time where you run to the bathroom, do not chance it you will have explosive diahrea.

Feb 11, 2019
Verified Buyer
  • 10 Pineapple Strawberry
Feb 10, 2019
Verified Buyer
  • 10 Pineapple Strawberry

My favorite flavor. And I've tried almost all of them.

Feb 10, 2019
Verified Buyer

After PRE it's almost impossible for me to fall a slip at night. I drank it it early in the morning before jim and wasn't able to slip half the night that day. I tried to take half of the doze but it doesn't work for my good slip either. Now instead of PRE I use POST jym before and after workout. It has similar ingredients but without caffeine.

Feb 09, 2019
Verified Buyer
  • 6 Refreshing Melon

Solid pre-workout drink. Has that alertness/focus feel to it that I look for in a preworkout. This was the first time I bought it though and the refreshing melon is terrible. It tastes like a washington apple shot... all I think about when Ive drank it! I will try another flavor in the future otherwise theres too many options to deal with the taste.

Feb 09, 2019
Verified Buyer
  • 10 Raspberry Lemonade

Not kidding, the only time I have ever **** my pants as an adult was after drinking this product. 10/10

Feb 08, 2019
Verified Buyer
  • 9 Raspberry Lemonade

works 100%

Feb 06, 2019
Verified Buyer
  • 9 Black Cherry
  • 10 Orange Mango
  • 9 Raspberry Lemonade
  • 10 Pineapple Strawberry
  • 4 Rainbow Sherbet
  • 6 Strawberry Kiwi

Pineapple strawberry and raspberry lemonade are really good but orange mango is on a whole other level! Stick away from rainbow sherbet and strawberry kiwi they are super sweet and have an aftertaste. I love pre jym... it’s not a high stimulant product. Jim is all about the science behind ingredients so he doesn’t just throw stimulants in a bottle. Pre jym will give you good energy, great pumps, and great recovery.

Feb 06, 2019
Verified Buyer
  • 9 Rainbow Sherbet
  • 6 Cherry Limeade

I hate reading all these negative reviews about this product. So far I have been taking Jym supplements off and on for several years now. Pre jym gives one hell of a boost and no crash while 2 hours in the gym. Does it taste great no but which preworkout taste good? Any preworkout that taste sweet and great probably contains to much sugar which is not good for you. Also this whole thing about California is dumb because California has a problem with every thing

Feb 02, 2019
Verified Buyer
  • 7 Raspberry Lemonade

Wont lie this product isnt terriblw but it does leave you nauseous and bloated when u lift. Like where you cant concentrate on lifting because your stomach is twisting. It makes you feel a crash and burn effect since it has so much caffeine. The beta-alanine sticks and you dont shake it for hours. Its just to much to handle in a preworkout. I would not use this product due to the side effects. I would strongly recommend no explode. Has worked the best for me.

Feb 01, 2019
Verified Buyer
  • 10 Natural Island Punch
  • 7 Refreshing Melon
  • 4 Rainbow Sherbet
Feb 01, 2019
  • 1 Strawberry Kiwi

I saw the high reviews from this brand on the internet and I decided to go the buy this at the store since I didn't want to wait for shipping and I ran out of the pre-work out I take normally. So I got Strawberry kiwi since it sounded good at the moment. next day I was excited when I woke up to try this new pre-workout. I normally mix with 8 to 12 oz of water and I chug my bottle as I drive to the gym and with no problems but since this was my first time using this product, the taste felt off and gross to where i had to sip it instead and I didn't recall much of an impact from this product during my workout for this occasion but I thought to myself maybe it will get better tomorrow. next day, I read the instruction and I actually followed them throughly, I didn't realize that you have to let this pre-workout settle for 10-15 minutes once I mix it, and you have to take it within a certain time of a certain time. so I thought maybe I would get better result and taste today. NOPE, this didn't make a difference at all for me, the taste is still pretty bad and it smells like a wine cooler and my wife said it looks gross. So whatever, I continue to try it and I keep hoping it will get better but I still can't seem to enjoy the product overall. Beside the taste being horrible and don't seem to feel much during my workout. but since I spent money on it I'm still using it and giving it a try for another week because i think its probably helping my workouts but I'm getting to the point of tossing it out and buying the other brand I used. I wonder who were the first few people to try this flavor and thought it was a good idea to go with it?

Jan 28, 2019
Verified Buyer
  • 10 Pineapple Strawberry

Tasted GREAT, however, it hurts your stomach and makes you feel so full and nauseous that it makes a workout unbearable. Not a great pump either. For the cost, it not worth it.

Jan 27, 2019

Taking into consideration California being the lead state in medical science within the country with the largest output of medical research, and the product legally stating "Concerning California Residents: This product contains chemicals known to the State of California to cause cancer and birth defects or reproductive harm"... Yeah I'd stay the **** away from this ****.

Jan 16, 2019
Verified Buyer
  • 3 Orange Mango

I have been using the Pre Jym, Pro Jym and Post Jym on a stack now for a couple weeks and it has been wreaking havoc on my bowels. I am not sure if it is because it is “cleansing” me or if my body just doesn’t agree with it. I literally am having straight liquid come out of my a-hole about an hour or hour and a half after my workouts and am going to the toilet 4-5 times a day now. I am using it as directed. Mixing Pre Jym with water, letting it set for 15 minutes, drinking it over the course of 15 minutes and consuming it 30 minutes before my workouts. Pro Jym is mixed with non-fat milk and consumed 30 minutes after work out. Post Jym is mixed with water, let stand for 15 minutes and then consumed directly after my Pro Jym and within 40-45 minutes after my workout. No other supplement stack I have ever taken has done this to me. For now, it isn’t too bad because I can be close to a bathroom at all times, but that won’t always be the case. Additionally, the Pre Jym doesn’t seem like it gives me the energy for my pumps. I had been taking NeuroCore pre-workout and while it did give me the jitters and made me feel like I wanted to claw my face off sometimes, it worked amazing in the gym when pumping some weight. Pre Jym doesn’t feel like that and I feel like I am falling flat on my pumps. I think that once I have used up the product that I currently have of the Jym line, I won’t be ordering again. Probably a good product, and probably better for me as opposed to other stuff I have been using, but I like results and I want to feel good about what I am using. Right now, I just don’t feel good with Jym.

2 Sizes
30 Servings
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8 Flavors
Cherry Limeade
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Price: $48.99  ($1.63 / Serving)
Flavor Rating: 8.5
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What's in JYM Supplement Science Pre JYM

30 Servings Cherry Limeade
Serving Size: 1 Scoop (26g)
Servings Per Container: About 30
Amount Per Serving % Daily Value
Calories 80       
Sodium 240 mg 10%
Total Carbohydrate 3 g 1%**
Total Sugars 2 g       
Includes 2g Added Sugars 4%
Creatine HCl (as CON-CRET®) 2 g
Beta-Alanine (as CarnoSyn®) 2 g
Betaine (Trimethylglycine) 1.5 g
Taurine 1 g
N-Acetyl-L-Cysteine 600 mg
Alpha-Glyceryl Phosphoryl Choline (as AlphaSize®) 150 mg
Citrulline Malate 6 g
Beet (Beta vulgaris L.) Root Extract 500 mg
L-Leucine 3 g
L-Isoleucine 1.5 g
L-Valine 1.5 g
L-Tyrosine 1.5 g
Caffeine Anhydrous 300 mg
Huperzine A [from Toothed Clubmoss (Huperzia serrata) Aerial Parts Extract] 50 mcg
Black Pepper (Piper nigrum) Fruit Extract (as BioPerine®) 5 mg
** The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
† Daily Value not established
Dextrose, Disodium Phosphate, Natural and Artificial Flavors, Sucralose, Acesulfame Potassium, Gum Blend (Cellulose Gum, Xanthan Gum, Carrageenan), FD&C Red #40.
ALLERGEN WARNING: Produced on shared equipment that also produces products that may contain EGG, MILK, SOY, TREE NUTS, and WHEAT.

Directions For Pre JYM: Mix 1 scoop of Pre JYM in 14oz. of water and drink 30-45 minutes before workouts.

Warnings: Check with a qualified healthcare professional before taking this product. Do not use if you are sensitive to caffeine, pregnant or nursing a baby, under 18 years of age, have any known or suspected medical conditions, and/or if you are taking any prescription or OTC medications. Pre JYM is an incredibly strong pre-workout matrix that contains 300mg caffeine per serving, the equivalent of approximately 3 cups of coffee. Avoid using with any other caffeinated products. Too much caffeine may cause nervousness, irritability, sleeplessness, and, occasionally, rapid heartbeat. Always begin use with 1/2 scoop or less and assess your tolerance. Once tolerance is assessed, take a maximum dose of 1 scoop. To avoid sleeplessness, do not consume within 6 hours of bedtime. Concerning California Residents: This product contains chemicals known to the State of California to cause cancer and birth defects or reproductive harm. KEEP OUT OF REACH OF CHILDREN.

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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