JYM Supplement Science


Food Supplement
Pre Workout with High Quality Ingredients
9.1  out of 10  (3,855 Reviews)
1 Size
30 Servings
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3 Flavors
Cherry Limeade
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Price: £39.99  (£1.33 / Serving)
Flavor Rating: 8.5
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Product Overview

"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 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 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 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 support your fitness goals.

Pre JYM Active Ingredients Matrix Features
  • Full amounts of 13 science-backed ingredients.
  • 6 grams of citrulline malate
  • 6 grams of BCAAs in the 2:1:1 ratio
  • 2 grams of creatine HCl
  • 2 grams of CarnoSyn® beta-alanine
  • 1.5 grams of betaine
  • 600 milligrams of N-acetyl L-cysteine
  • 500 milligrams of Beet Root extract
  • 300 milligrams of caffeine
  • 150 milligrams of AlphaSize® alpha-GPC
  • 5 milligrams of BioPerine®

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.
  • 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.
2 grams of Creatine HCl
  • Creatine increases physical performance in successive bursts of short-term, high intensity exercise. The beneficial effect is obtained with a daily intake of 3g of creatine.
  • Creatine HCl is made by attaching a hydrochloride (HCl) group to creatine.
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.
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.*
1.5 grams of Betaine
  • Betaine, also known as trimethylglycine (TMG), is a modified version of the amino acid glycine.
300mg of AlphaSize® Delivering 150mg of Alpha-Glyceryl phosphoryl choline (Alpha-GPC)
  • Alpha-glyceryl phosphoryl choline (alpha-GPC) is a naturally occurring phospholipid compound.
600mg of N-Acetyl L-Cysteine (NAC)
  • NAC is the amino acid cysteine with an acetyl group attached to it.
300mg of Caffeine
  • Caffeine contributes to an increase in endurance capacity and may help to increase alertness and concentration. Do not exceed a daily intake of 300 mg of caffeine. The beneficial effect is obtained with caffeine consumption at doses of 3 mg/kg body weight at least one hour prior to exercise.
  • 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.
JYM Supplement Science

Ratings & Reviews

Overall Rating
3,855 Ratings
Verified Buyer Rating
3,398 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.
Verified Buyer
  • 9 Black Cherry
  • 10 Orange Mango
  • 10 Pineapple Strawberry
  • 10 Rainbow Sherbet

Love this pwo. The flavors are excellent and it makes me feel great in the gym. Never mind that small little scoop, I want it all. The flavors have all been delicious. The new pineapple strawberry is maybe the favorite. The caffeine doesn't bother me, it might others. I drink it over 30-45 minutes though.

  • 10 Rainbow Sherbet

I met Dr. Jim at the Arnold and he gave me about 5 samples of the Rainbow Sherbert flavor. I don't believe in taking a preworkout that doesn't taste amazing regarldess of the ingredients. They cost too much to not have the flavor knock your socks off. The Rainbow Sherbert is quite possibly the best preworkout flavor I've ever had. I also had great energy, focus, and pumps at the gym. The price is a little high, but I would definitely try this stuff out if I were you when it's on sale. Good stuff!

Verified Buyer
  • 6 Orange Mango
  • 7 Rainbow Sherbet

This pains me to write here publicly but i'm feel obliged. I've been using JYM since the early days. I'd stock up on Orange Mango in bulk and when it was out of stock i'd be bummed. The new 2.0 formulations just taste, and smell, plain awful...however I do still buy them loyally; while they suck compared to the legacy JYM they are still tolerable just nowhere near as good hope is the feedback on this forum is leading to a revised formulation.

Verified Buyer
  • 9 Orange Mango

Great Product!! But for startes I would recommend taking maybe 3/4 or half a scoop so you dont get jittery. After taking it a few more times I can say it is amazing really like it and definitely getting another one!

Verified Buyer
  • 1 Cherry Limeade

As with most everyone else, I loved and trusted this product. However,,, with the 2.0 version I just can't buy it anymore. The taste is now horrid... I realize it shouldn't be about the taste but the original version was awesome and now it is disgusting to the point it is hard to choke it down. Can't fathom how Jim does not recognize this and fix it but I have moved on to pre-kaged instead. What a shame..

Verified Buyer
  • 1 Cherry Limeade

This really hurts a lot writing this review of this product but it has to be done and I hope that this can change in the future. When the old Pre Jym came out I loved the cherry limeade flavor so much that I bought this all the time. Now that time has passed and that this new Jym 2.0 came out I saw that cherry limeade was in its new container and I bought it. I was hoping for that same flavor from before. After tasting it I was disgusted with the change of the flavor. It hurts saying this but after trying this cherry limeade 2.0 I will no longer be using this supplement again until something gets changed with it. I don't know what the other original flavors taste like now but like this one, I have a strong feeling that they been messed with as well. I'm very sorry Dr. Jim but I can't keep using this supplement anymore.

  • 8 Black Cherry

Cramping/intestinal pain- I was very excited when the JYM line of products came out backed by Jim Stoppani. Once I started getting low on my previous pre/post I switched over but didn't start taking them until after a couple week break. It took some time to figure out after I started up again that the JYM pre workout mix was causing my some serious intestinal cramping. It's not something I've seen in reviews here for it so I thought I'd post in case there's more people out there. I had to stop taking it as it was just too much. I've used various pre-workout mixes and can't really seem to narrow down what the cause could be as I've had these ingredients in one form or another with my other supplements. Short: tastes great, backed by a well respected person in the exercise space, causes cramping and abdominal pain consistently with single scoop.

Verified Buyer
  • 7 Orange Mango

I used to use the original Pre Jym Orange & Mango so was annoyed when it vanished from the store. Recently purchased this new "2.0" version and was left a tad disappointed. The flavour is similar but it doesn't taste as fruity, almost watered down but at the same time the sweetness is through the roof. Doesn't feel like 300mg of caffeine either, I used to get quite a buzz from the original but this version feels more like a cup of regular coffee. I guess if you haven't tried the original or it was too strong for you then you may like this, but for me I'm left wishing they would revert to the original recipe. Perhaps it's a cost saving exercise as the ingredients look similar, but maybe lower quality?

Verified Buyer
  • 10 Orange Mango

Probably the best preworkout supplement I've had in a while. Definitely a comprehensive list of ingredients. Great, clean energy and focus. Solid pump. And the Orange Mango flavour is excellent.

Verified Buyer

I joined the JYM family through the PRO JYM. which I believe is by far the best protein the the market. So, I decided to move and try PRO/PRE JYM products. I am really confident that the ingredients are the best in both quality and dosis. My problem, is the flavor. It is just too sweet. And the flavor is too artificial. Leaves me with a bad taste. I really have a problem with that cause I am not enjoying the product.

Verified Buyer
  • 10 Natural Island Punch
  • 9 Orange Mango
  • 10 Cherry Limeade
  • 7 Rainbow Sherbet
  • 5 Strawberry Kiwi
Verified Buyer
  • 8 Refreshing Melon
  • 7 Black Cherry
  • 3 Natural Island Punch
  • 9 Orange Mango
  • 6 Raspberry Lemonade
  • 10 Rainbow Sherbet
  • 8 Cherry Limeade
  • 7 Strawberry Kiwi

Jym is the go to for my pre. He basically turned the supplement industry on its head for transparency a few years ago, and everything you need for a nice pump is in prejym. The rainbow sherbet is the best tasting pre on the market.

Verified Buyer
  • 7 Rainbow Sherbet

Sorry to say I’m on the fence with this product. The scooper like other have mentioned is huge. If you read my review of Pre-Kage I said the same thing. Pre Jym come with a lot of hype and a big price tag. I’m more than half way through my jar and if need be I will update this review but for right now I will not re buy this product because of cost, big scooper, and lack of effectiveness on me. Stay fit!

  • 5 Black Cherry

1. it's a big scoop and way too sweet 2.both my wife and I found it utterly useless. no energy, no pump, no drive, after hearing all the reviews I am totally disappointed even the latest version on NO xplode which I find week is far superior

Verified Buyer
  • 10 Orange Mango
30 Servings
30 Servings
£1.33 Per Serving

What's in JYM Supplement Science Pre JYM

Serving Size: 1 Scoop (26g)
Servings Per Container30
Per 26g Portion % Reference Intake
Energy (KJ) 335 kJ 15%*
Energy (kcal) 80 kcal       
Carbohydrate 3 g 1%*
Of Which Sugars 2 g **
Salt (As Sodium Chloride) 240 mg 4%*
Citrulline Malate 6 g **
L-Leucine 3 g **
L-Isoleucine 1.5 g **
L-Valine 1.5 g **
Creatine HCI (as CON-CRET®) 2 g **
Beta-Alanine (CarnoSyn®) 2 g **
Betaine (Trimethylglycine) 1.5 g **
L-Tyrosine 1.5 g **
Taurine 1 g **
Beet (Beta vulgaris) Root Extract 500 mg **
Choline Bitartrate 350 mg **
Caffeine Anhydrous 300 mg **
Alpha-Glyceryl Phosphoryl Choline (as AlphaSize®) 150 mg **
N-Acetyl L-Cysteine 100 mg **
Black Pepper (Piper nigrum) Fruit Extract (as BioPerine®) 5 mg **
* Reference Intake of an average adult (8400kJ/2000 kcal).
** Reference Intakes not established.
Other Ingredients:
Citrulline Malate, L-Leucine, Creatine Hydrochloride (as CON-CRET®), Beta-Alanine (as CarnoSyn®), Dextrose, L-Isoleucine, L-Valine, L-Tyrosine, Betaine (Trimethylglycine), Taurine, Sodium (as Disodium Phosphate), Sweeteners (Sucralose, Acesulfame Potassium), Flavouring, Beet (Beta vulgaris) Root Extract, Choline Bitartrate, Caffeine Anhydrous, Alpha-Glyceryl Phosphoryl Choline (as AlphaSize®), N-Acetyl L-Cysteine, Stabilisers (Cellulose Gum, Xanthan Gum, Carrageenan), Colour (Allura Red AC), Black Pepper (Piper nigrum) Fruit Extract (as BioPerine®).
For allergens, see ingredients in bold. Produced on shared equipment that also produces products that may contain EGG, MILK, SOYA, TREE NUTS, WHEAT.

Directions For Pre JYM: As a Food Supplement, mix 1 scoop of Pre JYM™ in 400 to 1000 mL of water and drink 30-45 minutes before workouts. Consider allowing Pre JYM to mix for 10-15 minutes before drinking. Also consider drinking it over the course of 15-30 minutes. Initially use 1/2 serving or less to assess tolerance. Once tolerance is assessed, take no more than 1 serving. To avoid sleeplessness, do not consume within 6 hours of bedtime.


Flavoured Food Supplement Powder with Amino Acids, Caffeine and Sweeteners

DO NOT USE IF YOU ARE UNDER THE AGE OF 18, PREGNANT OR NURSING, HAVE ANY KNOWN OR SUSPECTED MEDICAL CONDITIONS, ARE TAKING ANY PRESCRIPTION OR OVER THE COUNTER MEDICATIONS, OR SENSITIVE TO CAFFEINE. Consult with a qualified healthcare professional before using this or any other food supplement. Contains 300mg of caffeine per serving, the equivalent of approximately 3 cups of coffee. DO NOT USE WITH ANY OTHER CAFFEINATED PRODUCT. Too much caffeine may cause nervousness, irritability, sleeplessness and/or rapid heartbeat. Immediately discontinue use and consult your doctor if any adverse reactions occur.

Allura Red AC and Tartrazine may have an adverse effect on activity and attention in children. Do not exceed the recommended daily amount. This product should not be used as a substitute for a varied diet or a healthy lifestyle. KEEP OUT OF REACH OF CHILDREN

Manufactured in the US for: (UK) Ltd. Units 7-8 Foster Avenue Dunstable, Bedfordshire, LU5 5TA.

* 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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