Metabolic Nutrition’s ThermoKal Caffeine-Free Fat Burner

We call on Metabolic Nutrition to open this formula up and revise their label so that we can update this post..


ThermoKal is a caffeine-free fat burner from Metabolic Nutrition meant to stack with StimuKal, but we’re not a fan of the proprietary blend or instructions.

Awhile back on the blog, we covered the latest fat burner from Metabolic Nutrition (the creators of the original Synadrex), StimuKal, which was released after their previous fat burner Synedrex got pulled and Hi-Tech Pharma released Synadrene, marrying features from the two versions of Synedrex. The StimuKal profile looked respectable, but we had questions in regard to the dosing, since it was a massive proprietary blend.

Well, Metabolic is back with another fat burner, one that’s designed to be a caffeine-free option and can be easily stacked with StimuKal. ThermoKal is the follow up to StimuKal that really brings the heat to fat burning.

This is a caffeine-free fat burner, but it is not stimulant-free — there’s a couple stimulants inside. This is a similar situation to the now-discontinued Shift from PEScience, which was a caffeine-free fat burner that can be added to other fat burners that are missing its ingredients — so today we’ll see if ThermoKal is a worthy replacement to Shift.

But the quick answer is going to be no because this is a questionable proprietary blend with what we believe to be improper (or at least incomplete) dosage instructions on the label.

We’ve got more details ahead, but first, take a moment to check the best deal and coupons on PricePlow:

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ThermoKal Ingredients

Metabolic Nutrition ThermoKal Ingredients

ThermoKal contains a host of proven weight loss and thermogenic agents, but are they dosed properly?

Just like we saw with StimuKal, ThermoKal is a 100% proprietary blend. It’s packed with several proven thermogenic ingredients, but again, we have to question, are they dosed high enough to really feel the heat? And it would be good to know this first ingredient….

Note: Doses listed below are based on 1 capsule

  • Proprietary Blend (700mg)

    • Berberine HCl

      Berberine is an anti-inflammatory and cholesterol-reducing agent found in a number of herbs. It’s frequently encountered in glucose disposal supplements, but does pop up in fat burners from time to time.

      Research into berberine shows it’s handy regulating insulin levels and improving glucose disposal. The reason is that berberine activates AMPK (Adenosine Monophosphate-Activated Protein Kinase) while inhibiting Protein-Tyrosine Phosphatase 1B (PTP1B).[1] Increased AMPK activity serves to enhance insulin sensitivity, improve glucose uptake into cells, and lower glucose production in the liver.[2,3]

      WARNING: Take with a meal!!

      This is why proprietary blends suck.

      As a glucose disposal agent, berberine should be taken during or very close to a meal, preferably with some carbohydrates. If you take it and then don’t eat, your blood sugar could drop too low and you could feel lightheaded / faint.

      This is a serious ingredient, and to see it up front in a proprietary blend with no dosage disclosed is a bad idea. It’d be a lot more helpful if we had the dose so we could compare to research.

      Further, the label says nothing about taking this with a meal, which could be borderline dangerous for some individuals who forget to do so. We’re interested in losing weight and maintaining blood sugar, not flirting with a minor case of hypoglycemia, which could happen if you don’t eat near this.

      For these reasons, we aren’t going to recommend ThermoKal, regardless of what’s to come next.

    • Paradoxine

      Paradoxine Logo

      Paradoxine is the premier choice for Grains of Paradise extracts, but how much is in ThermoKal?!

      Paradoxine is the industry-leading patented Grains of Paradise extract that is the first of several effective stimulant-free fat burning ingredients in ThermoKal. We’ve gone into great detail about Paradoxine before in our mega post Grains of Paradise: Fat Fighting Spice of the Goddesses, so check there for all the info, but for some highlights of the ingredient:

      Clinical trials demonstrate Paradoxine increases energy expenditure and speeds fat loss.[4,5] The more calories you’re burning each day, by way of increased energy expenditure, leads to faster weight loss and less subcutaneous fat.[6].

      This is indeed our favorite stimulant-free fat-burning ingredient right now.

    • Kinetiq Citrus Aurantium (50% Extract)

      Kinetiq is the evolution of the older Advantra Z bitter orange extract standardized to 50% Citrus Aurantium extract. Similar to Advantra Z, Kinetiq binds to Beta-3 adrenergic receptors without affecting alpha-1, alpha 2, beta-1, or beta-2 receptors[7]. This means Kinetiq doesn’t affect heart rate or blood pressure, meaning it’s a stimulant-free fat burning supplement.

      Kinetiq contains p-synephrine, naringin, and hesperidin (all readily found in Citrus Aurantium), which improve the utilization of carbs via increased ATP production. Even more interesting is the newest piece of research showing that Kinetiq elevates resting metabolic rate by 183kcal![8]

      As if you needed more reasons to embrace Kinetiq, another study from 2015 found that synephrine improves performance by increasing power, volume load, and total reps completed.[9] Not only is Kinetiq a powerful fat burning ingredient, it’s also a formidable ergogenic as well!

      Remember, synephrine is a stimulant — ThermoKal is not stim-free. It’s just caffeine free.

    • Capsimax

      Capsaicin in Hot Peppers

      Capsaicin, one of the proven fat-burning ingredients in the formula, comes from hot peppers

      Capsimax is a highly concentrated, patented Cayenne Pepper Extract that’s frequently included in fat burners for its ability to oxidize fat and increase energy expenditure.[10]

      Often times, capsaicin can lead to heartburn, however, the encapsulation slows digestion and helps prevent that heartburn or any other side effects. So you get the thermogenic effects of Capsimax without the nasty GI upset!

      Capsimax has been around for a while and we never have a complaint about it unless it’s put into a powder formula. Good stuff.

    • TeaCrine

      If there’s a “next-generation” stimulant out there that could give other stims a run for their money, it’s TeaCrine – but mostly when in higher doses! Containing a 98% concentrated dose of theacrine, TeaCrine exerts many of the same stimulative effects as caffeine (due to similar structures), but TeaCrine doesn’t come with the ultra-fast tolerance build up like caffeine.[11]

      Basically, with TeaCrine, you can keep taking the same dose over and over and still experience the same great effects without having to up the dose. Also, when used for seven consecutive days, theacrine has been shown to reduce oxidative stress[12], and increase dopamine levels in the brain, similar to caffeine.[13]

      We really notice this stim when it’s at 100mg, but that’s expensive and it’s more often less than that. Chances are it’s somewhere around 25mg here(????), which we typically don’t really feel much.

    • Evodiamine

      Metabolic Nutrition StimulKal ThermoKal

      StimuKal and ThermoKal make a potent 1-2 punch to shed fat and get the body you’ve always wanted.

      Up next is another temperature-spiking ingredient in Evodiamine. This thermogenic supplement inhibits fat uptake, and also helps to take some of the “bite” out of other stimulants it’s paired with.[14], which will come in handy if you’re stacking StimuKal and ThermoKal together.

    • Black Pepper Extract

      Often included to improve bioavailability and absorption of other ingredients in supplements, black pepper extract also enhances fat loss and lowers lipid levels[15] This is due to piperine, the active alkaloid in black pepper that gives it its bite.

    • Yohimbine HCl

      Finally, we have one of the most popular weight loss ingredients around, Yohimbine. Useful for getting rid of “stubborn” fat, Yohimbine acts as an alpha-2-adrenergic blocking agent that increases noradrenaline.[16]

      In addition to freeing stored, stubborn fat, Yohimbine also helps suppress appetite, increase energy expenditure, and enhance lipolysis.[17,18,19,20]

      Unfortunately, again, we don’t know the quality of Yohimbine extract or how much is in ThermoKal, which may make some of you a bit weary. This is why proprietary blends suck.


Metabolic Nutrition Sasha

Metabolic Nutrition Athlete Sasha might be pumped for these products, but due to the poor dosing instructions, we simply can’t recommend it.

Metabolic Nutrition recommends assessing tolerance by using it initially without any other weight loss products. Do not use more than two capsules daily and assess tolerance before using ThermoKal in the evening.

Those instructions aren’t good enough!

But as we’ve alluded to earlier, the high dose of berberine means that you need to take this just before, during, or after a meal – preferably with carbs!! Taking it completely fasted and then not eating could lead to too low of blood sugar.

One bit of good news is that users who go to the Metabolic website and find the FAQ for this product may read, “Some users find that taking THERMOKAL 30 minutes before their morning meal provides enhanced energy and more explosive results.”

Why, oh why is Metabolic Nutrition not giving these instructions on the actual bottle?! Because that’s what should be written. Fail.



It’s the right side of this chart on berberine’s mechanisms where we get scared. Supplement brands need to better educate their consumers, or open up doses so we can compare to research.

ThermoKal could have made a good right hook to StimuKal’s jab, but we’ll pass. This proprietary blend and lack of proper label instructions is a potential recipe for disaster, or at least a recipe for a case of minor hypoglycemia.

If it were dosed decently, then ThemoKal could be a novel caffeine-free fat burner to add to your weight loss stack – berberine is truly one of the best herbs out there. But there’s just not enough good information and not enough proper instructions to make a sound decision.

When combined with StimuKal, it could be good… but we’re simply not taking the risk without knowing how much berberine is inside. But if you can remember to eat before you take it, then expect to feel the heat with ThermoKal — what else would you expect from a product with thermo in the title?!

Metabolic Nutrition Thermokal – Deals and Price Drop Alerts

Get Price Alerts

No spam, no scams.

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.

ThermoKal Proprietary Blend

We call on Metabolic Nutrition to open this formula up and revise the label so that we can update this post.

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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  1. Li Y, et al; Bioactivities of berberine metabolites after transformation through CYP450 isoenzymes . J Transl Med. (2011)
  2. Liu LZ, et al; The pivotal role of protein kinase C zeta (PKCzeta) in insulin- and AMP-activated protein kinase (AMPK)-mediated glucose uptake in muscle cells . Cell Signal. (2010)
  3. Kim WS, et al; Berberine improves lipid dysregulation in obesity by controlling central and peripheral AMPK activity . Am J Physiol Endocrinol Metab. (2009)
  7. Stohs SJ, Preuss HG, Shara M. A Review of the Receptor-Binding Properties of p-Synephrine as Related to Its Pharmacological Effects. Oxidative Medicine and Cellular Longevity. 2011;2011:482973. doi:10.1155/2011/482973.
  9. Ratamess NA, Bush JA, Kang J, et al. The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance. Journal of the International Society of Sports Nutrition. 2015;12:35. doi:10.1186/s12970-015-0096-5.
  10. Janssens, P, et. al; “Acute Effects of Capsaicin on Energy Expenditure and Fat Oxidation in Negative Energy Balance“; July 2013
  11. Cauli, O;Subchronic caffeine exposure induces sensitization to caffeine and cross-sensitization to amphetamine ipsilateral turning behavior independent from dopamine release.; Department of Toxicology and Centre of Excellence for Neurobiology of Dependence, University of Cagliari; 2008
  12. Li WX, et al.; “Theacrine, a purine alkaloid obtained from Camellia assamica var. kucha, attenuates restraint stress-provoked liver damage in mice.“; J Agric Food Chem.; 2013
  13. Feduccia A, et al.; “Locomotor activation by theacrine, a purine alkaloid structurally similar to caffeine: involvement of adenosine and dopamine receptors.”; Pharmacol Biochem Behav; 2012
  14. Noh, K, et. al; “Effects of rutaecarpine on the metabolism and urinary excretion of caffeine in rats”; Archives of Pharmacal Research; January 2011;
  15. Shah SS, Shah GB, Singh SD, et al. Effect of piperine in the regulation of obesity-induced dyslipidemia in high-fat diet rats. Indian Journal of Pharmacology. 2011;43(3):296-299. doi:10.4103/0253-7613.81516.
  16. Szemeredi K, et al; Simultaneous measurement of plasma and brain extracellular fluid concentrations of catechols after yohimbine administration in rats . Brain Res. (1991)
  17. Mizuki Y, et al; Differential effects of noradrenergic drugs on anxiety and arousal in healthy volunteers with high and low anxiety . Prog Neuropsychopharmacol Biol Psychiatry. (1996)
  18. Galitzky J, et al; Alpha 2-antagonist compounds and lipid mobilization: evidence for a lipid mobilizing effect of oral yohimbine in healthy male volunteers . Eur J Clin Invest. (1988)
  19. Callahan MF, Beales M, Oltmans GA; Yohimbine and rauwolscine reduce food intake of genetically obese (obob) and lean mice . Pharmacol Biochem Behav. (1984)
  20. Waluga M, et al; Cardiovascular effects of ephedrine, caffeine and yohimbine measured by thoracic electrical bioimpedance in obese women . Clin Physiol. (1998)

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