Everything You Need to Know About HMB

HMB is a clinically proven ergogenic aid that has been shown in over 50 human studies to improve strength and power gains, increase lean mass, and aid recovery. HMB, short for beta-hydroxy beta-methylbutyrate, is an active metabolite of leucine that has both anti-catabolic and anabolic properties. Due to these attributes, HMB reduces muscle protein breakdown while also inducing muscle protein synthesis. This means HMB can lead to rapid strength gains in less time, significantly increase lean muscle mass, support more complete muscle recovery, and reduce muscle damage from resistance exercise. In fact, a recent position stand by the International Society of Sports Nutrition validated these claims. Based upon a comprehensive review of the HMB literature, they concluded that HMB enhances muscle recovery by attenuating muscle damage; HMB increases muscle hypertrophy, strength, and power in trained and untrained populations when the appropriate exercise protocol is applied; HMB efficacy is manifested in the young and the elderly; and HMB is safe to consume. Like creatine, beta-alanine, and other well-studied and proven performance-enhancing compounds, HMB makes a solid addition to any athlete’s training regimen and supplement stack. For example, research has shown when HMB is combined with creatine, the ergogenic benefits, as compared with what could otherwise be achieved by either compound independently, are significantly increased.

How does HMB work?

HMB’s primary physiological functions are its capacity to stabilize the cell membrane of muscles, stimulate protein synthesis, and decrease protein breakdown. The mechanism is related to HMB’s role as an alternate substrate for cholesterol synthesis. The inhibition of cholesterol synthesis results in impaired muscle functions, increased muscular damage, and finally, muscular necrosis. To maintain membrane integrity, muscle cells rely on cholesterol synthesis. Increased intramuscular HMB may provide a readily available substrate for the synthesis of cholesterol needed to form and stabilize the muscle cell membrane. HMB has been shown to up-regulate muscle synthesis by the activation of the mTOR pathway and to decrease muscle breakdown by influencing the ubiquitin-proteasome-dependent pathways of protein degradation. Simply put, HMB shifts the balance of protein synthesis, tipping the scale in muscle's favor. When protein synthesis equals protein breakdown, there is no net gain of muscle protein. This is important in maintaining/increasing strength. Therefore, the increase in protein synthesis and decrease in protein breakdown achieved through HMB supplementation results in greater strength gains and faster recovery via net gains in muscle protein.

How does HMB stack up scientifically?

HMB has been extensively studied in athletes, alone and in combination with other supplements (such as creatine), as an adjunct to exercise to help improve body composition, strength, and performance. More than 50 human clinical studies, 20 review articles, and two meta-analyses published in peer-reviewed journals have demonstrated HMB’s effectiveness in increasing lean body mass (LBM) and strength, decreasing markers of muscle damage, and reducing muscle soreness. Furthermore, HMB’s benefits have been demonstrated in trained and untrained individuals, men and women, ranging from young adults to seniors. Let’s take a brief look at a few key studies that demonstrates HMB’s ergogenic effects.

HMB supplementation improves muscular strength, power, and body composition

Strength gains are maximized with the use of HMB. A meta-analysis of resistance-exercise training studies shows HMB supplementation results in increased strength gains. The studies showed increases for the trained and untrained, the young and the elderly, and men and women. While the magnitude of the effect varies with training intensity and the population studied, the overall effect was apparent. HMB significantly increases strength gains when supplemented during resistance-exercise training. A 1996 study by Nissen et al. discovered that resistance training in combination with HMB supplementation for 4 weeks, in 36 women and 39 men with varying levels of training experience, resulted in greater upper body strength (7.5 kg for HMB compared to 5.2 kg in the placebo group) and greater increases in lean body mass (1.4 kg vs. 0.9 kg) A 2016 study conducted by Wilson et al. investigated the effects of 12 weeks of HMB and ATP administration on lean body mass (LBM), strength, and power in trained individuals. A three-phase double-blind, placebo, and diet-controlled study was conducted. Phases consisted of an 8-week periodized resistance-training program (phase 1), followed by a 2-week overreaching cycle (phase 2), and a 2-week taper (phase 3). LBM was increased with a combination of HMB/ATP by 12.7%. In a similar fashion, strength gains after training were increased in HMB/ATP-supplemented subjects by 23.5%. Vertical jump and Wingate power increased 21.5% and 23.7%, respectively, in 12 weeks in the HMB/ATP-supplemented group. During the overreaching cycle, strength and power declined in the placebo group (4.3–5.7%), whereas supplementation with HMB/ATP resulted in continued strength gains (1.3%). In conclusion, HMB-FA and ATP in combination with resistance exercise training enhanced LBM, power, and strength. A 2011 study conducted by Muller aimed to determine whether HMB supplementation would increase the LBM and muscle power output (measured as the load a subject can bench press) in males who resistance trained for recreational purposes, after a combination of resistance weight training, eating a balanced set diet and, supplementation with HMB for 8 weeks. Two homogenous groups of 20 males were evaluated for initial strength capabilities and body composition. For eight weeks, the subjects lifted weights three times a week and followed a balanced diet. Creatine kinase activity decreased with HMB supplementation. Gains in muscle power output were greater in the experimental group, and fat percentage decreases were recorded with HMB supplementation.

HMB supplementation reduces markers of exercise-induced muscle damage and improves recovery

It's as true for the casual athlete as it is for the serious competitor: people feel the effects of a workout the next day. Yet, HMB is shown to benefit anyone involved in strenuous activity by minimizing muscle damage. HMB reduces muscle damage during hard exercise by minimizing protein breakdown. Less protein breakdown means improved muscle cell stability and less membrane damage. This reduction in muscle cell damage (leakage) is measured by a reduction of muscle damage markers, such as creatine phosphokinase (CPK) in the blood stream. A 2013 study conducted by Wilson et al. studied the effects of short-term supplementation with the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery, and hormone status following a high-volume resistance training session with trained athletes. Twenty resistance-trained males were recruited to participate in a high-volume resistance training session centered on full squats, bench presses, and deadlifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 hours post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol, and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329 %) than in the HMB-FA group (104 %). There was also a significant change in PRS, which decreased to a greater extent in the placebo than in the HMB-FA group. Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance. There were no acute changes in the plasma total of free testosterone, cortisol, or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session. In support of the above study, a 2012 study conducted by Sikorski et al. examined the acute effects of HMB-FA supplementation on muscle damage and PRS when initiating a high-volume resistance-training program. The results showed that when compared to placebo, HMB-FA led to decreased CPK, indicating reduced muscle damage, and an increase in PRS, meaning the subjects felt more recovered 48 hours after the training. In conclusion, HMB-FA minimized the initial muscle damage and improved recovery in trained athletes initiating a high-volume training program.

HMB supplementation improves aerobic performance

HMB improves aerobic performance in average, everyday athletes. HMB is shown to increase maximal oxygen consumption (VO2max) and improve the respiratory compensation point (RCP). It appears that HMB may reduce metabolic acidosis, and the research also shows that it helps athletes tolerate high-intensity activity over a long period of time. Research also shows that HMB lengthens the time to the onset of blood lactate accumulation (OBLA). HMB improves the training status of endurance athletes for positive effects on endurance performance. In a 2016 study conducted by Jeszka et al., HMB was supplemented in a double-blinded, placebo-controlled, crossover design in 58 highly trained males. To qualify, the subjects had to have a minimum of 5 years of training and a minimum of 4 sessions weekly in their sport discipline. The authors concluded that HMB had advantageous changes in increasing fat-free mass and reducing fat mass while also improving on indicators of aerobic metabolism, such as VO2max, time to ventilatory threshold, and power at ventilatory threshold. In a 2015 study conducted by Michalski et al., sixteen elite rowers were supplemented with HMB for 12 weeks in a double-blind, placebo-controlled, crossover study. VO2max increased with HMB supplementation as well as time to ventilatory threshold, threshold load, and threshold heart rate. The researchers concluded that supplementing with HMB was advantageous for endurance athletes in increasing aerobic capacity and power. In 2001, Vukovich et al. conducted a double-blind switchback study with HMB, leucine, and a placebo. The results showed that HMB supplementation increased the cyclists’ endurance as measured by VO2 peak and lactate threshold.

How to take HMB

The recommended dosage of HMB is three grams per day for average-size individuals. If you want to "customize" your dosage, research has shown that 38 mg per kg or 17 mg per pound of body weight each day is optimal (see chart for simplified dosage scale). You should divide the daily dosage into two or three equal servings and take these servings spread out over the day.
Weight Daily Dosage of HMB
140 lbs. 2.5 g
170 lbs. 3.0 g
200 lbs. 3.5 g
230 lbs. 4.0 g
260 lbs. 4.5 g
290 lbs. 5.0 g
(Each 30 lbs. increment) 500 mg or 0.5 g
In regards to HMB timing near or around a training session, it is recommended to take HMB an hour before exercise to help reduce muscle damage. If you are unable to take HMB before exercise, then take a dose immediately after your workout or training session. For example, if your workout in the evening, take one serving in the morning and one an hour before your evening workout. If you work out in the morning, take your first serving right before or after your morning workout and a second serving at night.


How long does it take to see results from HMB?
  • Studies show that measurable increases in strength and prevention of overtraining occur in only a couple of weeks; however, it will most likely take three or four weeks to produce results in regards to muscle hypertrophy and improved body composition
Are there any other supplements that I should use with HMB?
  • Research shows that HMB combined with creatine produces greater results than either HMB or creatine alone. HMB should be taken in combination with a balanced diet containing a daily protein intake of about one gram per pound of body weight, especially if you are actively exercising. If your diet isn't balanced or your protein intake is low, then HMB should be combined with the appropriate vitamin, mineral, protein, or energy supplement to balance your diet. Due to these recommendations, we suggest stacking HMB with NutraBio Creatine Monohydrate, 100% Whey Protein Isolate, MultiSport, and PRE.
Does HMB have any negative side effects?
  • Extensive clinical studies have been conducted to specifically evaluate the safety of HMB, and no negative side effects have been recorded in either men or women whether young or elderly. A summary of the effects of HMB on hematology, emotional profile, and adverse effects as measured in nine clinical studies showed only positive effects on cholesterol (7% decrease) and blood pressure (4.4 mm of Hg decrease).
Does HMB work for women?
  • Yes, published research results show that women who take supplemental HMB and exercised benefited from enhanced strength and improved body composition.
References: Wilson, J. M., Fitschen, P. J., Campbell, B., Wilson, G. J., Zanchi, N., Taylor, L., ... & Ziegenfuss, T. N. (2013). International society of sports nutrition position stand: beta-hydroxy-beta-methylbutyrate (HMB). Journal of the International Society of Sports Nutrition, 10(1), 1. Nissen, S., Panton, L., Wilhelm, R., & Fuller, J. C. (1996, March). Effect of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on strength and body composition of trained and untrained males undergoing intense resistance training. In Faseb Journal (Vol. 10, No. 3, pp. 1651-1651). 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998: FEDERATION AMER SOC EXP BIOL. Lowery, R. P., Joy, J. M., Rathmacher, J. A., Baier, S. M., Fuller Jr, J., Shelley 2nd, M. C., ... & Wilson, J. M. (2014). Interaction of Beta-Hydroxy-Beta-Methylbutyrate Free Acid (HMB-FA) and Adenosine Triphosphate (ATP) on Muscle Mass, Strength, and Power in Resistance Trained Individuals.Journal of strength and conditioning research/National Strength & Conditioning Association. Muller, M. (2010). Effect of β-hydroxy-β-methylbutyrate (hmb) supplementation on the body-composition and muscle power output of non competitive sporting males between 19 and 24 years who performed resistance training three times a week for 8 weeks (Doctoral dissertation, University of Pretoria). Wilson, J. M., Lowery, R. P., Joy, J. M., Walters, J. A., Baier, S. M., Fuller, J. C., ... & Duncan, N. M. (2013). β-Hydroxy-β-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained men. British Journal of Nutrition, 110(03), 538-544. Sikorski, E. M., Wilson, J. M., Lowery, R. P., Duncan, N. M., Davis, G. S., Rathmacher, J. A., ... & Walters, J. (2012). The acute effects of a free acid beta-hydoxy-beta-methyl butyrate supplement on muscle damage following resistance training: a randomized, double-blind, placebo-controlled study.Journal of the International Society of Sports Nutrition, 9(1), 1. Vukovich, M. D., & Dreifort, G. D. (2001). Effect of -Hydroxy -Methylbutyrate on the Onset of Blood Lactate Accumulation and Vo2peak in Endurance-Trained Cyclists. The Journal of Strength & Conditioning Research, 15(4), 491-497. Durkalec-Michalski, K., & Jeszka, J. (2015). The efficacy of a β-hydroxy-β-methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebo-controlled crossover study. Journal of the International Society of Sports Nutrition, 12(1), 1.