GBB (Gamma-Butyrobetaine Ethyl Ester): Super Carnitine That Makes You Sweat?!

If you follow PricePlow, you have likely tried a carnitine-based supplement in the past. What if we told you that everything you’ve taken may pale compared to the new kid on the block, GBB?

The short goes like this: Not only will it leave you sweating more than anything on the market, it still provides the amazing general health benefits associated with carnitine supplementation. Dive into this post to find out if this carnitine precursor is on a path to dethroning the carnitine world as we know it!


GBB Supplements

GBB, or Gamma-Butyrobetaine ethyl ester HCl, is the molecule that your body converts into L-Carnitine when naturally producing its own carnitine.

  • Pro-Carnitine: Studies show that its supplementation can increase the body’s plasma L-Carnitine levels by nearly double! Thus, the benefits of GBB are similar to the benefits of carnitine supplementation – they depend on the user’s diet and carnitine status.
  • Thermogenic! For some unknown reason (we have theories), GBB causes a serious amount of thermogenesis and sweating, especially if taken pre-workout, so it has been included in several new thermogenic fat burners.
  • Dosage: The typical dose is 10-20mg twice daily, and right now our conservative daily max is 50mg, although many have gone higher and studies have tested far higher.
  • GBB SupplementsFeatured GBB Supplements: There are several ways to use GBB, so it first depends on your form factor:
    • Fat Burning Powder: For a heated, energy-based fat burning drink, we’ve been incredibly impressed with SteelFit Steel Sweat.

    • Stimulant-Free Fat Burning Powder: AstroFlav Drip has 20mg GBB to get the sweat going.

    • Liquid L-Carnitine: If you’re a fan of doing “L-Carnitine” shots, then VMI Sports L-Carnitine 1500 Heat has a three-way blend of L-Carnitine on top of GBB and grains of paradise to keep you thermogenic!

  • Trusted Ingredient: We’ve tested and trusted ProGBB, which is manufactured by SYNMR Biotechnologies. Read more at (see their lab tests)
  • Safety: Safety studies even include infants, and GBB is theorized to be safer than carnitine supplements at these doses because there’s no chance of it turning into toxic D-Carnitine, which could potentially be in some carnitine supplements.

Watch our YouTube video about GBB

If you don’t feel like reading, you can also watch Mike, founder of PricePlow, explain GBB below:

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Up-Front: What are the typical GBB “claims”?

Gamma Butyrobetaine

Can as little as 10mg of this bad boy make you work up a sweat faster? For some of us, the answer is very much yes

The purpose of this post is to educate and investigate the science on GBB, a relatively new soldier on the supplement ingredient chess board. Formally known as Gamma-Butyrobetaine ethyl ester HCl, GBB is an ingredient we see in newer fat-burners. While there are several claims made about the benefits of GBB, they have usually used it as a “sweat amplification” agent in products like SteelFit’s Steel Sweat .

A few clinical trials that show GBB to be a formidable ingredient for the industry and certain types of dieters. The most impressive amongst these claims is a result that showed a near-doubling of plasma carnitine levels after supplementation, and an increase of 300% carnitine excretion.[1,2] In addition, it’s often advertised that GBB will function similarly to other carnitine supplements… but takes a step further due to its ability to raise plasma levels so incredibly high.

The recommended dosage of GBB sets it apart from other forms of carnitine supplements. While industry veterans like acetyl-l-carnitine (ALCAR) or l-carnitine-l-tartrate (LCLT) typically require doses closer to a gram, GBB works similarly to other forms of carnitine in far lower doses like 50mg per day. This is a huge win for GBB, as high doses of other carnitine supplements take up too much space (disadvantageous in a capsule) and simply cost more.

Gamma Butyrobetaine Ethyl Ester HCl Plasma Carnitine

An early study on carnitine’s precursors showed that GBB (to the right) is the best of the bunch at increasing plasma carnitine levels.[1]

“Super Carnitine”?

In past posts regarding GBB, we’ve called it “super carnitine”, as this is how several companies see the ingredient. It has clinical research backing its safety, it has a low active dose, and it raises carnitine levels in the body higher than other supplements. What’s NOT to love?

Seeing that nobody online has done any serious research on the ingredient, we dug up every scientific paper possible on GBB to see if these claims were true. Here’s what we came up with:

What is GBB?

Carnitine Biosynthesis Pathway

The Carnitine Biosynthesis Pathway.[3] GBB, or γBB, is circled in red.

Gamma-butyrobetaine eventually gets converted into l-carnitine. Through an enzyme known as Gamma-butyrobetaine dioxygenase (or BBD[3]), GBB is converted to L-carnitine. “GB dioxygenase”, as the name implies, is an oxidoreductase enzyme,[4] and these enzymes facilitate conversions through electron movement. By supplementing with GBB, you provide a “push” for the body to produce more L-Carnitine. Think of GBB like lumber set aside to build a house. More lumber equals more house!

To understand why it “pushes” the body to produce more L-carnitine, get ready for some basic general chemistry lessons. Chemical reactions tend to behave according to Le Chatelier’s principle. Le Chatelier’s principle is a law of equilibrium[5] — the body wants to maintain balance.

The GBB / L-Carnitine Equilibrium

If you add more GBB, you will get more carnitine until the “levels” of both product and reagent balance out. Likewise, if we have more product, enzymes can facilitate the breakdown of product into its constituent parts: more reagents. This allows the body to do its best to never have too much of any one thing. Due note that while it is never quite this simple in nature, it’s the easiest way to think of such reactions.

GBB Carnitine

The pathway image above is more detailed, but the point is that your body will do its best to maintain hemeostasis and can go in both directions

GBB supplementation likely works based on this principle. We add so much material to the left that the reaction goes to the right. It creates more carnitine to balance out the ratio of GBB and l-carnitine in the body. Tyrosine supplementation and even prohormones also work by helping conversion reactions go towards the right. It may be easier to just refer to GBB as “pro-carnitine”.

The enzyme for GBB conversion to carnitine is commonly found in the kidney, liver, and the brain.[6,7] Given the roles of the kidney and liver in fat metabolism, having GBB dioxygenase in these organs makes sense. Carnitine serves an essential role in fat metabolism that will be discussed more below.

To break out of textbook mode, let’s describe the mechanism as simply as we can: you put more on the left, you get more on the right. If you put more on the right, you get more from the left.

A Brush Up on Carnitine Itself

Carnitine is the molecule that facilitates movements of fatty acids during beta-oxidation, the process that lets us get energy from fats. It’s easy to visualize carnitine as a “fatty acid taxi cab” that takes the fatty acids to different spots within the mitochondria (the powerhouse of the cell).[8] Keto dieters should especially understand the situation well: once the fatty acids are dropped off by carnitine, they are converted into ATP through beta-oxidation. This process is going on constantly throughout the day but elevates during intensive exercise as fatty acids are burned for fuel.

Carnitine Function in Intracellular Transport

Carnitine’s Function in Intracellular Transport.[3] Note how important this molecule is if you plan on delivering fatty acids to cells. You can ignore the bottom yeast section.

Thus, it may make sense to take some before a workout: more taxis going to the destination means more guests will arrive, correct?

This is where GBB should kick in. By providing enough GBB, we allow the body to “push” the conversion reaction to the right, which means we get more carnitine. If we have more carnitine, we can transport more fatty acids into the mitochondria to burn as fuel. That’s the idea, anyway.

Does More Carnitine Actually Do Anything?

Let’s finally get to the crux of our pursuit: does GBB supplementation really do anything? We’re going to first tackle the benefits of carnitine supplementation before getting into the nitty gritty with the unique claims attached to GBB itself. The short answer is that carnitine has several benefits it can impart through proper supplementation, especially in those that are deficient. Carnitine is likely best known for improving brain health, as it improves focus, memory formation, and even the ability of the brain to resist disease or degradation.[9-11]

Vegan? Vegetarian? Aging? Then read up

But again, carnitine really shines for fat loss in those that are deficient. Vegans, vegetarians, and boomers should all consider giving carnitine a shot as supplementation is associated with improved fat oxidation (through its natural mechanism) and even enhanced intra-set recovery.[12] It may even help the deficient hold on to muscle mass more efficiently as these demographics age.[13,14]


Any form of carnitine is a good idea for vegans

In terms of general health, more carnitine is a good thing. Carnitine has been long-used to improve sperm quality on top of being a potent antioxidant.[15,16] It helps keep glucose levels down in the body while improving insulin sensitivity.[17] It may even be worth trying when treating symptoms of autism and ADHD![18,19]

The carnitine deficiency downfall

…And those benefits are only the most clear. There’s an uncountable number of things that can go wrong when your body cannot mobilize fat due to a carnitine deficiency, so there’s nearly as many things that it may improve in some form if you’re hampered by such a deficiency. So it’s tough to make claims about how it will specifically help you, it’s just easy to say that “being carnitine deficient is a bad thing”.

So yes, GBB will probably do something through virtue of improving creatinine levels in the blood. Carnitine itself is a very well studied compound, the only difference with GBB is the method of increment and the weight of the dose. While we lose out on the versatility of other forms of carnitine, like acetyl l-carnitine’s ability to cross the blood-brain barrier, we make up for it with a lower and more tolerable dose with some additional “fringe” benefits.

Current Research on GBB-Exclusive Health Benefits, Superiority, and Safety

Whenever a new supplement storms onto the scene, we go directly to studies that advocate for its safety. There have been far too many instances of new ingredients turning out to be ticking time-bombs.

In this matter, we will not lie — GBB took us by surprise. They studied GBB in human infants and determined GBB to be safe to take. Given that infants may be the most sensitive test subjects around, we can safely say GBB supplementation is probably safe for adults,[2] although we’d always welcome more toxicology research.

Safer due to no D-Carnitine?

In fact, some GBB manufacturers claim that GBB is likely safer than normal carnitine! While that must be taken with a grain of salt since they’re selling the ingredient, they present a sound argument: In short, the problem is that carnitine supplements may contain the D-carnitine enantiomer of L-carnitine.[20] D-carnitine is toxic in humans and mammals,[21] as it may reduce your body’s stores of carnitine and induce a deficiency!![22,23]

GBB can claim superiority in a few other realms beyond safety. Science has associated l-carnitine supplementation with gastric distress in high doses.[24-26] Anecdotal reviews concur. Since the dose of GBB is often much lower than other forms, it likely can circumvent this unfortunate side effect. Carnitine suffers from a poor bioavailability as the body may use only 18% of the dose.[27] While we have seen little data on the bioavailability of oral GBB, we’re hoping it’s better than 18%!

GBB leads to nitric oxide enhancement

Gamma Butyrobetaine Ethyl Ester Nitric Oxide

GBB elevates nitric oxide levels, but researchers don’t understand the entire pathway yet![28]

The first unique aspect of GBB is its consistent impact on nitric oxide levels.[28] At least a few studies have showed GBB to be a potent vasodilator. As workout fiends who are always down for enriched blood flow, we love nitric oxide boosters at PricePlow. By improving blood flow, GBB will probably help get nutrients to damaged muscle and joint tissue at a more rapid rate. It may even help keep blood pressure down. GBB has been more consistent in terms of vasodilation than other forms of carnitine.[28]

A sweaty situation!

Secondarily, GBB makes most athletes sweat far more than normal. This is often the main selling point, as some of us absolutely love to sweat when training. Note, however, that we’ve seen no direct science on why this may occur, but for some individuals, it’s incredibly effective at doing so…. to the point of some users being annoyed by it.

Gamma Butyrobetaine Ethyl Ester HCl Carnitine Excretion

While the carnitine levels doubled from GBB, the excretion was 30x higher, meaning there’s all kinds of carnitine turnover with GBB![1]

We can not find any real science on why this is occurring. One postulation of ours (with zero basis) is that the chemical reaction to get from GBB to Carnitine is exothermic (releases heat), and by triggering the reaction en masse via supplementation, it theoretically outputs the heat. If we stumble upon an explanation that’s based in actual science, we will update this article. Until then, we’ll leave this article at “it’s hot and makes most people sweat more for some reason”.

So if that’s not enough for the more conservative-minded folks who need to know every mechanism about every ingredient they take, then they may need to wait until more research is done.

GBB Dosage

Right now, the standard dosage seems to be 10-25mg twice per day, or 25-50mg in one shot. Lower doses will likely still yield benefits, they just may not be “felt”, while higher doses may work but may induce too much of the heated for too many individuals.

For this reason we aren’t going over 50mg per day right now… although many who are more aggressive than we are have taken that much twice per day.

Note, however, that the infant study used “500 µM γ-butyrobetaine”,[2] with 500 micromolar = 0.0005 moles, and GBB’s molar mass is 146.2074 g/mol. This then equates to 73mg GBB on the infants! Obviously we don’t usggest this, but we do think that adults can handle over 50mg.

In the other study, this happened at very high doses:

Participant 12 received 75 mg “y-butyrobetaine/(kg body wt-d). The solid inner salt was dissolved in fruit juice or carbonated beverage and consumed in two equal amounts daily at breakfast and dinner. Because participant 12 complained of excessive sweating and salivation 1-3 h after ingestion of the -y-butyrobetaine supplement, the dosage was reduced to 37.5 mg/(kg body wt-d) for participants 13-16. Only one of these subjects reported any unusual effects (mild increase in sweating on d 11-13) with that dosage of the supplement.[1]

It goes without saying that we don’t suggest such astronomical doses (37.5mg/kg is nearly a 3g dose), but it’s interesting to see that the researchers even bring up the excessive sweat and salivation!

So what are our favorite supplements with GBB inside? Since there’s so many ways to take it — from pills to powders to even topical creams — you have a great selection.

Let’s break it down:

  • AstroFlav Drip

    AstroFlav, a brand known for their out of this world flavors, updated their stimulant-free fat burning supplement named Drip in 2023.

    AstroFlav DRIP

    AstroFlav DRIP – Deals and Price Drop Alerts

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    Disclosure: PricePlow relies on pricing from stores with which we have a business relationship. We work hard to keep pricing current, but you may find a better offer.

    Posts are sponsored in part by the retailers and/or brands listed on this page.

    Note: In the image above, make sure you get the newer 2023 version with GBB.

  • SteelFit Steel Sweat

    Take a look at this beast – it has nearly every heated ingredient we know — including GBB — but not too much caffeine!

    SteelFit Steel Sweat

    If you’re crazy about heat, this label is loaded with thermogenic ingredients… but we’re definitely not recommending this to rookies right off the bat!

    SteelFit Steel Sweat – Deals and Price Drop Alerts

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    Disclosure: PricePlow relies on pricing from stores with which we have a business relationship. We work hard to keep pricing current, but you may find a better offer.

    Posts are sponsored in part by the retailers and/or brands listed on this page.

  • Liquid L-Carnitine: Musclesport CarniShred +Mitoburn

    Like doing flavored “shots” of L-Carnitine? Then this one is a must-try, because the flavors are great, there’s a good spread of L-Carnitine, and we have both moderate doses of GBB, MitoBurn L-BAIBA, and grains of paradise!

    MuscleSport Carnishred + MitoBurn

    Musclesport CarniShred +Mitoburn – Deals and Price Drop Alerts

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    Disclosure: PricePlow relies on pricing from stores with which we have a business relationship. We work hard to keep pricing current, but you may find a better offer.

    Posts are sponsored in part by the retailers and/or brands listed on this page.

Who’s the preferred GBB raw material supplier?


Looking for trusted, lab-tested GBB? Then it’s SYNMR’s ProGBB! Click the image or read more below

There are a few raw material ingredient suppliers providing GBB, but none have shown us the level of detail and lab testing of ProGBB, made by SYNMR Biotechnologies.

We were clued into ProGBB when investigating new fat burning powder ingredients. SYNMR agreed to share their lab tests, which reveal some great information:

ProGBB Lab Tests and Documentation

Four PDFs here tell an interesting story:

ProGBB Energy Test

Interesting: Collect enough GBB (which we don’t recommend taking at once), and you do get calories. This has been proven for amino acids like BCAAs too.

We learn some interesting things from the documents above, such as the idea that large quantities of GBB has calories (of course, we’d never take so much as to get any level of usable energy from it). In addition, very high doses did not cause rat toxicity, but in extremely high doses, they do. All of the doses tested are so far beyond what’s used in human supplements that we do not have concerns.

You can learn more by heading to or trying SteelFit Steel Sweat!


PricePlow loves carnitine – especially the right kind for the right consumer. No, we don’t think it’s a miracle supplement, and it’s not always for everyone all the time, but we definitely enjoy it.

Well, one of our favorite supplement categories has just gotten a whole lot more interesting.

GBB is a worthy addition to the “carnitine wars”, as it has its place in products – especially capsule-based thermogenic fat burners – that use it over ALCAR or LCLT. For those that suffer gastric distress from other forms of carnitine, GBB may be the way to go. For those that hate taking a ton of powder or pills, GBB is the way to go.

However, ALCAR should still be better than GBB for cognitive benefits due to its ability to cross the blood-brain barrier, and LCLT has some other androgenic workout benefits. But in terms of carnitine production for vegans, vegetarians, meat-haters, the aging, and keto-dieters, we’re thinking GBB may be superior to LCLT or straight L-carnitine.

So, is GBB worth it? Depending on the situation, we think it’s at least worth trying. We always encourage you to make sure you do your research (several citations are below) and pick the form of carnitine that best serves your individual needs.

And if you do choose to use a supplement with GBB inside, don’t forget your towel, because you just might be one of the lucky ones who gets the sweat amplification effect.

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About the Author: Mike Roberto

Mike Roberto

Mike Roberto is a research scientist and water sports athlete who founded PricePlow. He is an n=1 diet experimenter with extensive experience in supplementation and dietary modification, whose personal expertise stems from several experiments done on himself while sharing lab tests.

Mike's goal is to bridge the gap between nutritional research scientists and non-academics who seek to better their health in a system that has catastrophically failed the public.

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