2023-10-08 00:30:04
New meta-analyses added
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We added a few meta-analyses to our database and update the clinical effects accordingly.
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HMB
•Last Updated: October 8, 2023
HMB is a metabolite of the essential amino acid leucine that plays an anticatabolic role in muscle tissue. In addition to preventing muscle protein breakdown, HMB may help improve strength and muscle mass in older adults, but evidence of a benefit for athletes is lacking.
HMB is most often used for
Last Updated:October 8, 2023
HMB, or hydroxymethylbutyrate, is an active metabolite of the essential amino acid leucine, and approximately 5% of dietary leucine converted to HMB.
HMB primarily prevents muscle protein breakdown and reduces fat-free mass loss, especially during catabolic states like aging and certain diseases. However, it does not appear to enhance body composition or strength in athletes.
HMB is generally well tolerated at a daily dose of 3 grams, and no significant adverse effects have been reported. Although higher doses may also be safe, limited research exists on doses above 3 grams.
HMB works by promoting muscle protein synthesis through stimulation of the mTOR pathway and activation of the GH/IGF-1 axis while also reducing protein breakdown by inhibiting the ubiquitin-proteasome system and caspases.
Note that HMB is also known as:
- Hydroxy-MethylButyrate
- beta-hydroxy-beta-methylbutyrate
HMB should not be confused with:
- Leucine (parent amino acid)
Supplementation of HMB tends to be in the dosage range of 1–3 grams daily for the purpose of reducing muscle mass losses over time (anticatabolic). As HMB is said to be 20-fold more potent than leucine for this purpose, it is seen as equivalent to 20–60g of leucine supplementation.[1]
HMB, a water-soluble metabolite of leucine, is excreted in the urine and is not reabsorbed by the kidneys back into the bloodstream. Studies have shown that approximately half of the supplemented HMB is lost through urine. Since the kidneys don’t reabsorb HMB, dividing the daily HMB dosage into three separate doses throughout the day may help to maintain steadier levels of HMB in the blood and thereby enhance its effectiveness.[2][3]
For the purpose of muscle protein synthesis (MPS), HMB and leucine are fairly equivalent, although the latter (leucine) may be more potent on a per-gram basis. Supplementing with HMB is not advised for inducing muscle protein synthesis, since leucine is likely more effective as well as cheaper.
Supplementation of HMB prior to an exercise session to mitigate exercise-induced muscle damage would require the usage of an HMB free acid rather than a calcium salt, and the above dosage range still holds. For this specific purpose, HMB is to be taken 30–60 minutes before a workout when taking the HMB-FA form, or 60–120 minutes if taking the HMB-Ca form. On the other hand, when HMB is consumed in preparation for a potentially skeletal-muscle-damaging event (e.g., a competition), or prior to a high-intensity training bout for the purpose of reducing muscle damage, it appears to be more effective when taken regularly three times a day starting at least 2 weeks before the training period.[4]
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2023-08-01 16:56:13
FAQ and database update
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We added newly published studies to our FAQs and database.
🚧 Under Renovation 🚧
The information in this section is slated for renovation — it will soon be transformed into a more usable (and readable!) form in the coming months. As such, the text in this section may be out of date and not up to Examine’s current standards for writing style.
- ^Gabriel J Wilson, Jacob M Wilson, Anssi H ManninenEffects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A reviewNutr Metab (Lond).(2008 Jan 3)
- ^Nissen S, Sharp R, Ray M, Rathmacher JA, Rice D, Fuller JC, Connelly AS, Abumrad NEffect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training.J Appl Physiol (1985).(1996-Nov)
- ^Rahimi MH, Mohammadi H, Eshaghi H, Askari G, Miraghajani MThe Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis.J Am Coll Nutr.(2018)
- ^Jacob M Wilson, Peter J Fitschen, Bill Campbell, Gabriel J Wilson, Nelo Zanchi, Lem Taylor, Colin Wilborn, Douglas S Kalman, Jeffrey R Stout, Jay R Hoffman, Tim N Ziegenfuss, Hector L Lopez, Richard B Kreider, Abbie E Smith-Ryan, Jose AntonioInternational Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB)J Int Soc Sports Nutr.(2013 Feb 2)
- ^May PE, Barber A, D'Olimpio JT, Hourihane A, Abumrad NNReversal of cancer-related wasting using oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine, and glutamine.Am J Surg.(2002-Apr)
- ^Clark RH, Feleke G, Din M, Yasmin T, Singh G, Khan FA, Rathmacher JANutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled studyJPEN J Parenter Enteral Nutr.(2000 May-Jun)
- ^Nicolas de Angelus Costa Riela, Maiara Moeme Alvim Guimarães, Daniela Oliveira de Almeida, Edilene Maria Queiroz AraujoEffects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Elderly Body Composition and Muscle Strength: A Review of Clinical TrialsAnn Nutr Metab.(2021 Mar 12)
- ^Wu H, Xia Y, Jiang J, Du H, Guo X, Liu X, Li C, Huang G, Niu KEffect of beta-hydroxy-beta-methylbutyrate supplementation on muscle loss in older adults: a systematic review and meta-analysis.Arch Gerontol Geriatr.(2015)
- ^Josephine S Jakubowski, Everson A Nunes, Filipe J Teixeira, Victoria Vescio, Robert W Morton, Laura Banfield, Stuart M PhillipsSupplementation with the Leucine Metabolite β-hydroxy-β-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-AnalysisNutrients.(2020 May 23)
- ^Holland BM, Roberts BM, Krieger JW, Schoenfeld BJDoes HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis.J Strength Cond Res.(2022-Feb-01)
- ^Sanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A, Sadarangani KP, Cristi-Montero CEffects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trialsJ Sci Med Sport.(2018 Jul)
- ^Rathmacher JA, Nissen S, Panton L, Clark RH, Eubanks May P, Barber AE, D'Olimpio J, Abumrad NNSupplementation with a combination of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine is safe and could improve hematological parameters.JPEN J Parenter Enteral Nutr.(2004)
- ^Gallagher PM, Carrithers JA, Godard MP, Schulze KE, Trappe SWBeta-hydroxy-beta-methylbutyrate ingestion, part II: effects on hematology, hepatic and renal function.Med Sci Sports Exerc.(2000-Dec)
- ^Baier S, Johannsen D, Abumrad N, Rathmacher JA, Nissen S, Flakoll PYear-long changes in protein metabolism in elderly men and women supplemented with a nutrition cocktail of beta-hydroxy-beta-methylbutyrate (HMB), L-arginine, and L-lysine.JPEN J Parenter Enteral Nutr.(2009)
- ^Eley HL, Russell ST, Baxter JH, Mukerji P, Tisdale MJSignaling pathways initiated by beta-hydroxy-beta-methylbutyrate to attenuate the depression of protein synthesis in skeletal muscle in response to cachectic stimuli.Am J Physiol Endocrinol Metab.(2007-Oct)
- ^Gerlinger-Romero F, Guimarães-Ferreira L, Giannocco G, Nunes MTChronic supplementation of beta-hydroxy-beta methylbutyrate (HMβ) increases the activity of the GH/IGF-I axis and induces hyperinsulinemia in rats.Growth Horm IGF Res.(2011-Apr)
- ^Lecker SH, Jagoe RT, Gilbert A, Gomes M, Baracos V, Bailey J, Price SR, Mitch WE, Goldberg ALMultiple types of skeletal muscle atrophy involve a common program of changes in gene expression.FASEB J.(2004-Jan)
- ^Smith HJ, Mukerji P, Tisdale MJAttenuation of proteasome-induced proteolysis in skeletal muscle by {beta}-hydroxy-{beta}-methylbutyrate in cancer-induced muscle loss.Cancer Res.(2005-Jan-01)
- ^Eley HL, Russell ST, Tisdale MJMechanism of attenuation of muscle protein degradation induced by tumor necrosis factor-alpha and angiotensin II by beta-hydroxy-beta-methylbutyrate.Am J Physiol Endocrinol Metab.(2008-Dec)
- ^Berton L, Bano G, Carraro S, Veronese N, Pizzato S, Bolzetta F, De Rui M, Valmorbida E, De Ronch I, Perissinotto E, Coin A, Manzato E, Sergi GEffect of Oral Beta-Hydroxy-Beta-Methylbutyrate (HMB) Supplementation on Physical Performance in Healthy Old Women Over 65 Years: An Open Label Randomized Controlled Trial.PLoS One.(2015)
- ^Tritto AC, Bueno S, Rodrigues RMP, Gualano B, Roschel H, Artioli GGNegligible Effects of β-Hydroxy-β-Methylbutyrate Free Acid and Calcium Salt on Strength and Hypertrophic Responses to Resistance Training: A Randomized, Placebo-Controlled Study.Int J Sport Nutr Exerc Metab.(2019 Sep 1)
- ^Osuka Y, Kojima N, Sasai H, Wakaba K, Miyauchi D, Tanaka K, Kim HEffects of exercise and/or β-hydroxy-β-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in older women with low muscle mass: a randomized, double-blind, placebo-controlled trial.Am J Clin Nutr.(2021 Oct 4)
- ^Suryawan A, Rudar M, Fiorotto ML, Davis TADifferential regulation of mTORC1 activation by leucine and β-hydroxy-β-methylbutyrate in skeletal muscle of neonatal pigs.J Appl Physiol (1985).(2020 Feb 1)
- ^Tomaszewska E, Donaldson J, Kosiński J, Dobrowolski P, Tomczyk-Warunek A, Hułas-Stasiak M, Lamorski K, Laskowska-Woźniak D, Muszyński S, Blicharski R, Blicharski Tβ-Hydroxy-β-Methylbutyrate (HMB) Supplementation Prevents Bone Loss during Pregnancy-Novel Evidence from a Spiny Mouse (Acomys cahirinus) Model.Int J Mol Sci.(2021 Mar 17)
- ^Tomczyk-Warunek A, Blicharski T, Jarecki J, Dobrowolski P, Muszyński S, Tomaszewska E, Rovati LCThe effect of maternal HMB supplementation on bone mechanical and geometrical properties, as well as histomorphometry and immunolocalization of VEGF, TIMP2, MMP13, BMP2 in the bone and cartilage tissue of the humerus of their newborn piglets.PLoS One.(2021)
- ^Hułas-Stasiak M, Jakubowicz-Gil J, Dobrowolski P, Tomaszewska E, Muszyński SMaternal β-hydroxy-β-methylbutyrate (HMB) supplementation during pregnancy affects early folliculogenesis in the ovary of newborn piglets.Theriogenology.(2019 Apr 1)
- ^Nissen S, Faidley TD, Zimmerman DR, Izard R, Fisher CTColostral milk fat percentage and pig performance are enhanced by feeding the leucine metabolite beta-hydroxy-beta-methyl butyrate to sows.J Anim Sci.(1994 Sep)
- ^Flummer C, Theil PKEffect of β-hydroxy β-methyl butyrate supplementation of sows in late gestation and lactation on sow production of colostrum and milk and piglet performance.J Anim Sci.(2012 Dec)
- Low-density lipoprotein (LDL) - Richard B. Kreider, Maria Pontes Ferreira, Michael Greenwood, M. Wilson, Pamela Grindstaff, Steven Plisk, Jeff Reinardy, Edward Cantler, and Anthony L. AmaldaEffects of Calcium β-HMB Supplementation During Training on Markers of Catabolism, Body Composition, Strength and Sprint PerformanceJournal of Exercise Physiology.()
- Low-density lipoprotein (LDL) - Wei Hung, Tsung-Han Liu, Chung-Yu Chen, Chen-Kang ChangEffect of β-hydroxy-β-methylbutyrate Supplementation During Energy Restriction in Female Judo AthletesJournal of Exercise Science & Fitness.()
- Muscle Mass - Vukovich MD, Stubbs NB, Bohlken RMBody composition in 70-year-old adults responds to dietary beta-hydroxy-beta-methylbutyrate similarly to that of young adultsJ Nutr.(2001 Jul)
- Muscle Mass - Portal S, Zadik Z, Rabinowitz J, Pilz-Burstein R, Adler-Portal D, Meckel Y, Cooper DM, Eliakim A, Nemet DThe effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled studyEur J Appl Physiol.(2011 Sep)
- Muscle Mass - Slater G, Jenkins D, Logan P, Lee H, Vukovich M, Rathmacher JA, Hahn AGBeta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained menInt J Sport Nutr Exerc Metab.(2001 Sep)
- Muscle Mass - Thomson JS, Watson PE, Rowlands DSEffects of nine weeks of beta-hydroxy-beta- methylbutyrate supplementation on strength and body composition in resistance trained menJ Strength Cond Res.(2009 May)
- Body Fat - Holland BM, Roberts BM, Krieger JW, Schoenfeld BJDoes HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis.J Strength Cond Res.(2022-Feb-01)
- Muscle Soreness - Hoffman JR, Cooper J, Wendell M, Im J, Kang JEffects of beta-hydroxy beta-methylbutyrate on power performance and indices of muscle damage and stress during high-intensity trainingJ Strength Cond Res.(2004 Nov)
- Liver Enzymes - Kreider RB, Ferreira M, Wilson M, Almada ALEffects of calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation during resistance-training on markers of catabolism, body composition and strengthInt J Sports Med.(1999 Nov)
- Power Output - Gallagher PM, Carrithers JA, Godard MP, Schulze KE, Trappe SWBeta-hydroxy-beta-methylbutyrate ingestion, Part I: effects on strength and fat free massMed Sci Sports Exerc.(2000 Dec)
- Muscle Damage - Rahimi MH, Mohammadi H, Eshaghi H, Askari G, Miraghajani MThe Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis.J Am Coll Nutr.(2018)
- High-density lipoprotein (HDL) - Sadeghi B, Bahari H, Jozi H, Hasanzadeh MA, Hashemi D, Bideshki MVEffects of β-hydroxy-β-methylbutyrate (HMB) supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials.Front Nutr.(2024)
- Muscle Soreness - Nunan D, Howatson G, van Someren KAExercise-induced muscle damage is not attenuated by beta-hydroxy-beta-methylbutyrate and alpha-ketoisocaproic acid supplementationJ Strength Cond Res.(2010 Feb)
- Power Output - Wilson JM, Lowery RP, Joy JM, Walters JA, Baier SM, Fuller JC, Stout JR, Norton LE, Sikorski EM, Wilson SM, Duncan NM, Zanchi NE, Rathmacher Jβ-Hydroxy-β-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained menBr J Nutr.(2013 Jan 3)
- Body Fat - Su H, Zhou H, Gong Y, Xiang S, Shao W, Zhao X, Ling H, Chen G, Tong P, Li JThe effects of β-hydroxy-β-methylbutyrate or HMB-rich nutritional supplements on sarcopenia patients: a systematic review and meta-analysis.Front Med (Lausanne).(2024 Jul 12)