Calcium β-Hydroxy-β-Methylbutyrate (CaHMB)

Calcium β-Hydroxy-β-Methylbutyrate (CaHMB) Common Name

β-hydroxy-β-methylbutyric acid

Top Benefits of HMB

  • Supports exercise performance*
  • Supports muscle structure and function*
  • Supports healthy metabolic pathways*
  • Supports healthy aging*

What is HMB?

β-Hydroxy-β-Methylbutyric acid (HMB) is a metabolite of the essential amino acid L-leucine, with roughly 5% of dietary l-leucine converted into HMB. HMB is best known for supporting skeletal muscle function, particularly in supporting recovery from muscle damage, mitigating muscle protein breakdown, and countering age-related muscle loss. 

Neurohacker’s HMB Sourcing

There are two main forms of HMB used as a dietary supplement. One is a calcium salt (Calcium HMB or CaHMB). The other is a free fatty acid form. We decided to use CaHMB, because it has been the most-studied form of HMB. 

HMB Dosing Principles and Rationale

For ergogenic purposes (i.e., to enhance sports performance) and to counter muscle wasting syndromes HMB is usually dosed at either 1.5 or 3 grams a day (3 grams is the more common dosage). This is a much larger dose of HMB than what’s made in the body. The capacity to make HMB is influenced by diet. It’s estimated that a healthy adult produces about 0.3 grams (i.e., 300 mg) of HMB per day. A person with a high dietary intake of leucine might make two or three times more, while a diet lower in leucine would result in less. HMB is also affected by age: Our body makes less HMB from leucine as we get older. We selected a dose of HMB intended to support this more physiological HMB range.

HMB Key Mechanisms 

Exercise performance (ergogenic effects)

  • Protects from muscle damage and muscle protein degradation (muscle loss / sarcopenia) [1–12]
  • Supports muscle strength and mass [9–14]
  • Supports muscle structure and function [14]
  • Supports endurance performance [15]
  • Supports post-exercise recovery [6]
  • Supports mitochondrial function in muscles [16]


  • Supports healthy insulin sensitivity [17]
  • Downregulates fat accumulation and blood/liver lipid levels [17]
  • Upregulates adiponectin levels [18]

Signaling pathways

  • Upregulates peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1α) [18]
  • Upregulates nuclear transcription factors of mitochondrial biogenesis (nuclear respiratory factor 1 [NRF1]) [18]
  • Downregulates proliferator-activated receptor gamma (PPARγ) [18]
  • Upregulates AMP-activated protein kinase (AMPK) signaling [18, 19]
  • Upregulates SIRT1 signaling [19]


  • Synergistic with resveratrol in upregulating AMPK and SIRT1 [19]
  • May be additive with creatine for muscle performance [9]


[1] A. P. Rossi et al., Drugs Aging. 34, 833–840 (2017).
[2] H. Wu et al., Arch. Gerontol. Geriatr. 61, 168–175 (2015).
[3] K. A. van Someren, A. J. Edwards, G. Howatson, Int. J. Sport Nutr. Exerc. Metab. 15, 413–424 (2005).
[4] A. E. Knitter, L. Panton, J. A. Rathmacher, A. Petersen, R. Sharp, J. Appl. Physiol. 89, 1340–1344 (2000).
[5] P. Ostaszewski et al., J. Anim. Physiol. Anim. Nutr. . 84, 1–8 (2000).
[6] J. M. Wilson et al., Br. J. Nutr. 110, 538–544 (2013).
[7] M. H. Rahimi, H. Mohammadi, H. Eshaghi, G. Askari, M. Miraghajani, J. Am. Coll. Nutr. 37, 640–649 (2018).
[8] D. J. Wilkinson et al., Clin. Nutr. (2017), doi:10.1016/j.clnu.2017.09.024.
[9] E. Jówko et al., Nutrition. 17, 558–566 (2001).
[10] S. Nissen et al., J. Appl. Physiol. 81, 2095–2104 (1996).
[11] L. B. Panton, J. A. Rathmacher, S. Baier, S. Nissen, Nutrition. 16, 734–739 (2000).
[12] J. M. Wilson et al., Eur. J. Appl. Physiol. 114, 1217–1227 (2014).
[13] S. L. Nissen, R. L. Sharp, J. Appl. Physiol. 94, 651–659 (2003).
[14] J. R. Stout et al., Exp. Gerontol. 48, 1303–1310 (2013).
[15] M. D. Vukovich, G. D. Dreifort, J. Strength Cond. Res. 15, 491–497 (2001).
[16] R. A. Standley et al., J. Appl. Physiol. 123, 1092–1100 (2017).
[17] M. H. Sharawy, M. S. El-Awady, N. Megahed, N. M. Gameil, Can. J. Physiol. Pharmacol. 94, 488–497 (2016).
[18] Y. Duan et al., Food Funct. 9, 4836–4846 (2018).
[19] A. Bruckbauer et al., Nutr. Metab. . 9, 77 (2012).