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In my decade-long career as a supplement store manager and nutrition coach, I have tried dozens of pre-workouts, and it’s been difficult to find a caffeine-free formula that still provides all of the other benefits I look for (increased blood flow, strength, energy, and mental focus).
Transparent Labs Stim-Free checks all the boxes and is a fantastic pre-workout for anyone looking to increase strength and energy while avoiding stimulants like caffeine.
Key Takeaways
Honest Review Guarantee from FeastGood: Our testing team purchases each product 100% independently and uses the product for several weeks up to several months before writing a review. Learn more about our review process here.
- Transparent Labs Stim-Free costs around $1.66 per serving. When I analyzed over 50 pre-workouts, the average cost was around $1.61 per serving. However, many other clinically-dosed pre-workouts cost over $2 per serving, so Stim-Free provides excellent value.
- Transparent Labs Stim-Free uses clinical doses for all of its proven ingredients and uses patented forms of ingredients that have been proven effective in high-quality research studies. This makes Stim-Free very effective despite not having any stimulants.
- Transparent Labs Stim-Free is a great option for lifters who want to optimize strength and performance but want to avoid the side effects of stimulants like jitteriness or anxiety. The stim-free formula is also great for late-night exercisers.
Overall Rating: 3.8/5
4.0 /5
Price
4.0 /5
Taste
4.0 /5
Mixability
2.0/5
Energy
4.0 /5
Pump
5.0 /5
Strength
4.0/5
Price
4.0/5
Taste
4.0/5
Mixability
2.0/5
Energy
4.0/5
Pump
5.0/5
Strength
Overview
Features
Best For
Medical Disclaimer: The material presented in this article aims to offer informational insights. It should not be perceived as medical guidance. The views and writings are not designed for diagnosing, preventing, or treating health issues. Always consult with your physician prior to starting any new dietary or supplement routine.
What Is Transparent Labs Stim-Free?
Stim-Free is the caffeine-free pre-workout formula offered by Transparent Labs. It is designed to improve strength, blood flow, energy, and recovery without the use of caffeine or other stimulants.
Transparent Labs uses clinical doses of the most important ingredients like citrulline (8g), beta-alanine(4g), and taurine (1.3g) to ensure that you are getting the full benefit for these ingredients.
They also use a lot of patented ingredients, like BetaPure™ and elevATP®, which have been clinically proven to be effective, further ensuring great results from this product.
This is a winning combination: Using doses that have been proven effective and using patented ingredients that have been studied using the highest quality research methods. The end result is a highly effective product.
Like all Transparent Labs products, Stim-Free is third party tested and uses no artificial sweeteners, no artificial colors, and no artificial preservatives.
Note: Transparent Labs has three different pre workout formulas, Stim Free being one of them. I’ve reviewed the other two forumluas as well, which you can read here: Transparent Labs Bulk Review and Transparent Labs Lean Review.
Claims vs Reality: How I Felt After Taking Transparent Labs Stim-Free?
I am absolutely obsessed with this pre-workout.
I already knew about the quality of the products that Transparent Labs puts out, but I was over the moon to find a caffeine-free formula that encompasses all aspects of what I am looking for in a pre-workout: pump, strength, endurance, recovery, and energy.
I experimented in using this pre-workout for my late night workouts and found that I still had incredible performance, despite being exhausted from the demands of a full day’s work followed by a full evening of parenting two preschoolers.
I also used this product during my deload week. I tend to take one week every 4-6 weeks as a deload, where I decrease total workout volume and intensity and reduce my caffeine intake to help reset my tolerance and avoid dependency.
Despite planning on decreasing volume during my deload week, when I used this product I found that I had the strength and energy to follow my regular rep and set scheme, and had to remind myself to reduce the weight that I was lifting.
I specifically tried the Peach Mango flavor, and found it enjoyable when mixed with the recommended 10-12oz of water.
If you’ve read any of my other pre-workout reviews, then you know that I tend to concentrate my pre-workouts by mixing them with less water than recommended. I do this to avoid having to use the bathroom when doing long-distance runs outside, and to avoid the sensation of water sloshing around in my stomach.
When mixed with 6-8oz of water, the Peach Mango flavor was still really enjoyable. Browsing the different flavor options on the Transparent Labs website, I can’t wait to add cherry limeade and sour grape to my supplement shelf.
Transparent Labs Stim-Free
Transparent Labs Stim-Free is a great option for lifters who want to optimize strength and performance, but want to avoid the side effects of stimulants like jitteriness or anxiety. The stim-free form is also great for late night exercisers
Transparent Labs Stim-Free Ingredients
Transparent Labs contains clinical doses of 7 key ingredients: citrulline, beta-alanine, betaine, taurine, elevATP, ginseng, and Bioperine ®.
This combination provides good stamina, energy, and pump without the use of caffeine or stimulants.
Transparent Labs does not use any artificial flavors or colors in their formula, but you will see other additives like beet root powder for color.
Ingredient | Dose | Clinical Effective Dose | Meets Clinical Standards |
---|---|---|---|
Citrulline Malate | 8000 mg | 6000-8000 mg | ✅ |
Beta-Alanine | 4000 mg | 3000 mg | ✅ |
Betaine Anhydrous | 2500 mg | 2500 mg | ✅ |
Taurine | 1300 mg | 1000-3000 mg | ✅ |
L-Tyrosine | 1000 mg | n/a | n/a |
ElevATP ® | 150 mg | 150 mg | ✅ |
Senactiv ® (Panax notoginseng) | 50 mg | 50 mg | ✅ |
Bioperine ® | 5 mg | 5 mg | ✅ |
Huperzine | 100mcg | n/a | n/a |
Citrulline
Citrulline is an amino acid that helps to increase nitric oxide levels in the body. Transparent Labs uses a compound called Citrulline Malate, which is citrulline bound to malic acid. This combination allows the citrulline to be better absorbed and utilized by the body.
When nitric oxide levels are increased, the result is improved vascularity and blood flow which can improve muscle function and reduce fatigue.
The clinically effective dose of citrulline for improving muscle function is 6000-8000mg taken 60 minutes before exercise.
Transparent Labs stim-free offers a full 8000mg of citrulline, which is the top end of the effective dose.
Beta-Alanine
Beta-alanine is an amino acid that plays a part in synthesizing carnosine in the body. Carnosine can act as a buffer for hydrogen ion buildup in the muscles, which in turn delays muscular fatigue.
Therefore, supplementing with beta-alanine increases muscle carnosine levels (by anywhere from 15-85%), which can lead to increased workout volume and endurance.
Beta-alanine supplementation comes with a side effect called paresthesia, or skin tingling. It’s a harmless side effect, and some people love the sensation because it tells them that their pre-workout has “kicked in”. Other users find the side effect distracting.
The clinical dose of beta-alanine is between 3000-6000mg, and should be taken daily over the course of several weeks to fully saturate the body and experience its full benefit.
With 4000mg per scoop, Transparent Labs Stim-Free meets clinical dosing standards.
Betaine Anhydrous
Betaine anhydrous is a compound that we can find in certain foods including beets and spinach. It helps to create carnitine in the body. Carnitine is a compound that helps convert fat to energy.
When you supplement with higher doses of betaine (~2500 mg daily), you can increase carnitine levels in the body which can help reduce fat mass when paired with regular physical activity.
Transparent Labs Stim-Free meets clinical dosing standards for betaine with 2500mg per scoop.
Taurine
Like betaine, taurine is also an amino acid that can be found naturally in foods including meat, fish, and dairy products.
Taurine has a role in energy metabolism, as well as glucose and fat regulation.
Because of its role in energy metabolism, taurine can increase athletic performance by increasing time to exhaustion. It has also been shown to increase strength and power and reduce feelings of muscle soreness after a workout.
There is limited research, but the currently accepted dosing strategy is to take 1000-3000mg 60-180 minutes before exercise.
With a dose of 1300mg, Transparent Labs Stim-Free meets the clinical dose.
L-Tyrosine
Tyrosine is a slightly controversial sport supplement, in that it doesn;t have a definite dosing strategy when used as a pre-workout.
Much of the research around Tyrosine uses doses of 100-150mg per kg of body weight, equal to between 7000-10000mg for a 150lb person.
This is well above the dose typically found in pre-workouts, which is 500-1000mg.
Despite the lack of research so far, because tyrosine is a precursor to dopamine and norepinephrine, it shows promise for increasing work output by delaying the time to fatigue.
For the purposes of this article, I am going to state that no clinical dosing standards for short-term athletic performance have been established.
ElevATP ®
ElevATP® is a patented blend of ancient peat and apple polyphenols. In clinical trials, ElevATP® has been shown to increase levels of ATP in the body and lead to increases in strength, power, and performance.
The clinical dose of ElevATP® is 150mg daily, taken approximately 30 minutes before training.
Transparent Labs uses the exact clinical dose in their Stim-Free preworkout.
Senactiv ®
Senactiv® is another patented blend, this time using the rosa roxburghii fruit and Panax notoginseng root.
Panax notoginseng specifically has been shown to increase aerobic capacity in adults.
The blend of ingredients used in Senactiv ® allows the ingredients to be absorbed and utilized more effectively by the body. This means that while the dose of Panax Notoginseng used in clinical trials was 1350mg, you only need 50mg of Senactiv® to elicit the performance benefits.
Transparent Labs Stim-Free uses the recommended 50mg of Senactiv® in their formula.
Bioperine ®
Bioperine® is a patented black pepper extract. Black pepper extract was shown in clinical trials to increase nutrient absorption by up to 30%.
It is added to pre-workout supplements to increase the absorption of the other ingredients in the pre-workout, rendering the pre-workout more effective.
Transparent Labs Bulk uses the clinical dose of 5mg of Bioperine® in its product.
Huperzine
Huperzine is a chemical derived from moss that can increase chemical messengers like acetylcholine in the brain. This can result in improved memory and cognitive function.
Despite the fact that research has demonstrated that huperzine likely isn’t a beneficial pre-workout ingredient, it is still included in the vast majority of pre-workouts on the market.
Research on humans has used a 200mcg dose of Huperzine before exercise, and Transparent Labs Stim-Free has 100mcg per scoop.
- Related Article: Transparent Labs Pump Review: My 1-Month Results Revealed
Highlights: What I Like About Transparent Labs Stim-Free
Clinical Dosing
Transparent Labs Stim-Free contains clinical doses of all 7 ingredients for which clinical doses have been established. This results in a pre-workout that is highly effective and lives up to its label claims.
Specifically, I found Stim-Free to be really effective for pump, strength, and endurance.
It does contain ingredients like betaine which are beneficial for improving body composition, but the majority of results like increasing lean muscle mass or reducing fat mass are going to be a result of your diet and lifestyle, and not the ingredients found in pre-workout supplements.
High Quality Ingredients
Transparent Labs is third party tested to make sure that the ingredients found within the product match what’s on the label. Their products are also tested for purity, with the results publicly displayed online.
This third party testing provides an extra level of safety and quality guarantee. Transparent Labs also uses patented forms of some ingredients, like BetaPure ™ for their beta-alanine, and elevATP ®.
Ingredients that are patented have been proven effective in high quality clinical trials, which is another level guaranteeing that this pre-workout will provide the results that it claims to.
Good Taste
Taste is subjective, of course, but I tried the Peach Mango flavor and found that it had a nice taste, without being overbearingly sweet. Because Transparent Labs doesn’t use any artificial flavors, it does have a slightly bitter aftertaste.
As someone who’s been using pre-workout products for more than ten years, I am pretty accustomed to the naturally bitter and sour taste of a lot of the ingredients found in pre-workout.
If you are new to using pre-workout, then the fact that this product uses high doses of bitter and sour ingredients might make the taste slightly unappealing for you.
Stim-free Formula Means Its Good for Everyone
The stim-free formula is suitable for every level of lifter: beginners who want to ease into pre-workouts as well as intermediate to advanced lifters who want to work out in the evening or take a deload week to reset their caffeine tolerance.
If you like how you feel on the Stim-Free formula, then you can add inexpensive caffeine tablets as needed, or try Transparent Labs Bulk, which offers a similar formula to Stim-Free, but with the addition of caffeine and other mental focus ingredients.
Drawbacks What I Did Not Like About Transparent Labs Stim-Free
Doesn’t Provide as Much Energy and Focus
This product does not provide a substantial boost to energy or mental focus, but it’s not really designed to. It did provide good physical energy and stamina, but since it is a stimulant-free formula, it isn’t a great option to wake you up and give you a mental boost.
I was hard-pressed to find something about Stim-Free that I didn’t like. This was really the only knock against it, which isn’t really a drawback since the stim-free formula isn’t designed to provide mental energy.
How Does Transparent Labs Stim-Free Stack Up Against Our Criteria For Pre Workouts
Price
Our rating: 4/5
At $1.66 per serving for clinical doses of high-quality ingredients, Transparent Labs Stim-Free offers fantastic value for what’s provided.
For comparison, many pre-workouts on the market that offer similar doses and ingredients cost anywhere from $2.00 to $3.00 per serving.
That being said, since some pre-workouts on the market provide reasonable benefits for as low as $0.95 per serving, there may be some more cost-effective options on the market for people with very strict budgets.
Taste
Our rating: 4/5
Transparent Labs Stim-Free comes in 8 different flavors, ranging from sweet options like peach mango and blue raspberry to sour options like sour grape and cherry limeade.
Taste always comes down to personal preference, but the fact that Transparent Labs offers so many flavor options makes it likely that you can find one that you enjoy.
Transparent Labs uses stevia and natural flavors in all of their products, and no artificial sweeteners. As a result, the product can have a slightly bitter or sour aftertaste since this is the natural flavor of the raw ingredients used.
Mixability
Our rating: 4/5
Transparent Labs Stim-Free dissolves almost entirely, with little to no residue when you drink it immediately. If allowed to sit for a while (10-15 minutes), there is a small amount of undissolved product that will settle at the bottom.
I didn’t find the undissolved portion to be an issue, since I drank my pre workout pretty quickly. The small amount of sediment can be avoided if you swirl your cup before taking a sip, which won’t allow the product to settle.
Energy
Our rating: 2/5
Transparent Labs Stim-Free does provide some physical/muscle energy to help you power through challenging workouts. It does not, however, provide a strong mental energy or mental focus like traditional caffeinated pre-workouts do.
That being said, the stim-free formula is designed specifically for people who are sensitive to stimulants/caffeine or for people who are looking to cycle off stimulants.
It is not formulated to provide the jittery energy that some other pre-workouts do. With the addition of elevATP ® in the formula, which has been clinically proven to increase ATP production, you do still feel good overall energy when taking Transparent Labs Stim-Free.
Pump
Our rating: 4/5
With a full 8g clinical dose of citrulline, Transparent Labs Stim-Free Pre workout provides a good muscle pump. This formula uses a specific form of citrulline called citrulline malate which increases how effectively the citrulline is used and absorbed in the body.
The end result is increased nitric oxide production and blood flow which can help increase strength and provide an aesthetic muscle pump.
Strength
Our rating: 5/5
Increasing muscular strength and stamina is where Transparent Labs Stim-Free pre-workout really shines. Each ingredient in the formula helps contribute to increasing muscular strength in some way.
Despite the lack of stimulants, when using Transparent Labs Stim-Free, I found myself finishing my workouts with energy left in the tank, despite being on a deload week or workout out late in the evening.
I noticed this most prominently during upper body strength days (though that could also be attributed to increased motivation from seeing a great upper body muscle pump).
Who Should Take Transparent Labs Stim-Free?
Transparent Labs Stim-Free is for:
- Lifters who are looking to maintain performance during a deload week
- People who work out late at night
- People who are sensitive to caffeine or want to avoid the potential negative side effects of caffeine like anxiety, jitteriness, or heart palpitations
- Individuals who prioritize high-quality ingredients and extra quality assurances like transparent third-party testing
Related: Transparent Labs Stim-Free vs Pump: 7 Differences (TESTED)
Who Should Not Take Transparent Labs Stim-Free?
Transparent Labs Stim-Free is not for:
- People who identify as “stim-junkies” and are looking for a high caffeine and mental focus blend
What Are Other Customers Saying About Transparent Labs Stim-Free?
Aside from the actual Transparent Labs website, I was hard-pressed to find customer reviews for Transparent Labs Stim-Free.
On the Transparent Labs website, I can see the rating breakdown for Stim-Free. That is, I can see how many people gave it various star ratings:
- 5 stars (886)
- 4 stars (163)
- 3 stars (25)
- 2 stars (25)
- 1 star (20)
So while the feedback is overwhelmingly positive, the script on the Transparent Labs website still doesn’t allow me to click on the one-star reviews and read what the customers have listed, without sifting through the 1100+ reviews.
Reading through the reviews, customers praise the great taste and love the fact that it provides good energy without a crash.
Customers are happy that they don’t experience jitters like they do with traditional high-stim pre-workouts, and love the pump and quality that Transparent Labs Stim-Free provides.
It seems especially popular among lifters who work out in the evening or are trying to cycle off of caffeinated products.
After jumping through to page 209 of the reviews, I did finally come across some 1-star reviews. The reviews there didn’t offer a ton of insight, though a few people said they didn’t like the taste and a couple of people felt like the pre-workout didn’t do anything for them.
Lots of the 1-star reviews also related to slow shipping times, which can be outside of the control of the company itself.
Transparent Labs Stim-Free Alternative
Transparent Labs Bulk
If you have come across this review, and love the sounds of this product but you want something that offers a higher caffeine level and more dedicated mental focus ingredients, then consider trying Transparent Labs Bulk.
- Read my complete Transparent Labs Bulk Review
Bulk contains similar ingredients to Stim-Free, like 8g of citrulline, 4g of beta-alanine, 2.5g of betaine, and 1.3g of taurine.
In place of elevATP ®, however, Bulk offers Alpha-GPC, caffeine, l-theanine, and theobromine as their mental focus and stimulant blend.
The addition of theanine with the caffeine makes for more prolonged energy without the crash or jitters, so even though it’s a caffeinated pre-workout, users still report fewer side effects compared to other pre-workouts.
Both products come in 30-serving containers and have the same cost per serving.
Like the Stim-Free Preworkout, Bulk has no artificial flavors, colors, or preservatives in its formula.
Are There Any Promos or Discounts For Transparent Labs Stim-Free?
There is a Subscribe and Save feature on the Transparent Labs website. When you sign up, you save 10% off of all products you order and you get free shipping (within the US).
With this feature, you can set your subscription to auto-ship every 30, 45, or 60 days. You can pause or cancel your subscription at any time.
Frequently Asked Questions
Is Transparent Labs Stim-Free The Best Pre Workout?
Transparent Labs Stim-Free tops the charts as far as caffeine-free pre-workouts go. The formula is clinically dosed, comes at a reasonable cost per serving, and comes at a good cost per serving. It’s a great formula for pump, strength, and endurance.
Is Transparent Labs Stim-Free Third Party Tested?
All Transparent Labs products are third party tested with their testing results displayed publicly on their website.
Is Transparent Labs Stim-Free Good For Weight Loss?
Transparent Labs Stim-Free does contain some ingredients that can support improving body composition, like betaine. The overall formula is better designed for increasing strength and energy, but with more effective workouts you can burn more calories leading indirectly to increased weight loss.
Is Transparent Labs Stim-Free Safe For Women?
Transparent Labs Stim-Free is a great and effective formula for women. It should not be used while pregnant or breastfeeding.
How Much Caffeine Does Transparent Labs Stim-Free Have?
Transparent Labs Stim-Free contains zero caffeine or stimulants. This makes it a great option for people who are sensitive to caffeine, people who workout in the evenings, or those looking to cycle off of stimulants.
Does Transparent Labs Stim-Free Have Creatine?
Transparent Labs Stim-Free does not contain any creatine. If you want creatine, they have a Creatine HMB formula available that can be added to your pre-workout.
How Long Does Transparent Labs Stim-Free Last For?
Transparent Labs Stim-Free provides good muscle energy and strength for workouts lasting anywhere from 45 minutes to 2 hours. Because it doesn’t contain caffeine, you don’t have to worry about trouble sleeping after taking it.
Does Transparent Labs Stim-Free Need To Be Cycled?
Transparent Labs Stim-Free does not need to be cycled. It does not contain ingredients like stimulants or ingredients affecting hormones which traditionally should be cycled.
Will Transparent Labs Stim-Free Make Me Jittery?
Transparent Labs Stim-Free will not make you feel jittery or anxious. These are side-effects typically associated with caffeine and stimulants, which the Stim-Free Preworkout doesn’t contain.
What Flavors Are Available For Transparent Labs Stim-Free?
Transparent Labs Stim-Free is available in 8 different flavors: Cherry Limeade, Sour Grape, Blue Raspberry, Peach Mango, Strawberry Lemonade, Green Apple, Orange, and Tropical Punch.
Where Is Transparent Labs Stim-Free Made?
Transparent Labs Stim-Free is manufactured in a facility in Utah in a cGMP compliant facility.
What Is Transparent Labs’ Shipping Policy?
Shipping cost and time vary depending on where the product is being shipped to. Within the USA, items can be expedited in as little as 1-3 business days. International orders can take up to 14-21 business days to arrive.
What Is Transparent Labs’ Return Policy?
Unopened products can be returned within 30 days of purchase. If you have already opened your product, you can request an exchange or store credit, but a credit is not guaranteed. Either way, you can start your return by contacting the support team at support@transparentlabs.com.
How To Contact Transparent Labs?
You can reach Transparent Labs by phone at 1-866-324-9557 or by email at support@transparentlabs.com
You can also find Transparent Labs active on social media on Facebook, Instagram, TikTok, and Youtube.
Transparent Labs Stim-Free
Transparent Labs Stim-Free is a great option for lifters who want to optimize strength and performance, but want to avoid the side effects of stimulants like jitteriness or anxiety. The stim-free form is also great for late night exercisers
References
Gough, L.A., Sparks, S.A., McNaughton, L.R. et al. A critical review of citrulline malate supplementation and exercise performance. Eur J Appl Physiol 121, 3283–3295 (2021). https://doi.org/10.1007/s00421-021-04774-6
Bellinger PM. β-Alanine supplementation for athletic performance: an update. J Strength Cond Res. 2014 Jun;28(6):1751-70. doi: 10.1519/JSC.0000000000000327. PMID: 24276304.
Blancquaert L, Everaert I, Derave W. Beta-alanine supplementation, muscle carnosine and exercise performance. Curr Opin Clin Nutr Metab Care. 2015 Jan;18(1):63-70. doi: 10.1097/MCO.0000000000000127. PMID: 25474013.
Van Every, Derrick W. BS1; Plotkin, Daniel L. BS1; Delcastillo, Kenneth BS1; Cholewa, Jason PhD2; Schoenfeld, Brad J. PhD1. Betaine Supplementation: A Critical Review of Its Efficacy for Improving Muscle Strength, Power, and Body Composition. Strength and Conditioning Journal 43(4):p 53-61, August 2021. | DOI: 10.1519/SSC.0000000000000622
Kurtz, J.A., VanDusseldorp, T.A., Doyle, J.A. et al. Taurine in sports and exercise. J Int Soc Sports Nutr 18, 39 (2021). https://doi.org/10.1186/s12970-021-00438-0
Tumilty, L., Davison, G., Beckmann, M. et al. Oral tyrosine supplementation improves exercise capacity in the heat. Eur J Appl Physiol 111, 2941–2950 (2011). https://doi.org/10.1007/s00421-011-1921-4
Liang, Yq., Tang, Xc. Comparative studies of huperzine A, donepezil, and rivastigmine on brain acetylcholine, dopamine, norepinephrine, and 5-hydroxytryptamine levels in freely-moving rats. Acta Pharmacol Sin 27, 1127–1136 (2006). https://doi.org/10.1111/j.1745-7254.2006.00411.x
About The Author
Jennifer Vibert is a Certified Strength and Conditioning Specialist, Nutrition Coach, and supplement store manager. She has a Bachelor of Kinesiology with a major in Fitness and Lifestyle and a minor in Psychology from the University of Regina. She is a Certified Nutrition Coach through Precision Nutrition, with a passion for helping clients learn the fundamentals of nutrition and supplementation in order to build healthy, sustainable habits.
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