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What is HMB?

Scroll down for everything you need to know about HMB.

The Basics

HMB (or β-Hydroxy β-Methylbutyrate) is a naturally occurring compound found in muscle. It’s made naturally from the amino acid leucine.

Supplementing with~3g/d HMB has been shown to increase strength, power and muscle and also improve endurance performance with training

It works by reducing muscle damage from training so you recover quicker, and adjusting muscle protein breakdown and production so you adapt to training faster.HMB is a well studied compound with an excellent safety record that has helped many people on their athletic journey.

What is HMB?

HMB is a metabolite of the amino acid leucine. It’s also found in foods like alfalfa, fish and citrus fruit

HMB is stored in the muscle and is vital to muscle function. It is used to protect and repair muscle cell membranes and has also been found to increase muscle protein production and slow down muscle protein breakdown. 

HMB has gained popularity as a dietary supplement after being discovered in the 1990s by Dr Steve Nissen, a professor at Iowa State University. Dr Nissen carried out the first research on HMB showing that supplementing with 3g/d improved strength and muscle mass in resistance trained athletes. 

Since then HMB has been widely studied in many athletic populations by various researchers across the globe. In  2013 the International Society of Sports Nutrition (ISSN) published a position stand stating that HMB improves strength, power and endurance performance in training athletes.

Where your body gets HMB from

The body naturally makes 1g/d HMB from amino acids

We get about 0.5g/d HMB from foods like fish and citrus

Research shows that an additional 3g/d HMB impacts performance

How does HMB work?

HMB works by slowing protein breakdown and speeding up protein synthesis in repair. HMB is also a vital structural component used to maintain the integrity of muscle cell membranes, preventing them from damage and supporting rebuild.


HMB is important in muscle health. It is stored in the muscles and used to build, maintain and repair muscle cells.


HMB is bound to Calcium to keep it stable as a powder and more soluble in water. Calcium is also good for bone health. Evidence from cancer studies suggests that HMB may inhibit the ubiquitin-proteasome proteolytic pathway, a series of chemical reactions that work to break down muscle protein.


This means you are less likely to lose muscle mass through damage or inactivity. HMB is also thought to stimulate the production of muscle protein to be used in the muscle adaptation process through a series of chemical process collectively called the m-TOR pathway.

Considering the way that HMB is thought to work, it is likely to be more beneficial to athletes that experience muscle damage and soreness on a regular basis. This is especially relevant for pre-season training, and constantly varied training methods such as CrossFit. Learn the benefits of HMB for CrossFit athletes here.


In endurance athletes this means that muscles rapidly change to become more energy efficient whereas in the strength athlete muscle cells will grow more quickly to generate more power. Overall, using HMB enhances your recovery from, and adaptation to all types of training. It is a product that can be used by all athletes that are training hard, and at high volume, regardless of their sporting event. Constantly varied functional fitness programs like CrossFit as well as weightlifting and powerlifting are well known for causing frequent muscle soreness.

What to expect when taking HMB?

HMB has a very bitter taste, so usually comes in capsule form or a blended and flavored powder. Research shows it is cleared from your body quite quickly, so you’ll need to take it 2-3x a day for the best results (we suggest 2x, am and pm). Blonyx HMB Sport comes in a capsule. Our HMB+ Creatine is an unflavored powder that can be mixed with your favourite smoothie, protein shake, or taken on its own.

If you’re training for performance

NOTE:  

HMB supports muscle adaptation and recovery. It will be less effective if you’re not training at your limits/at a higher intensity to get this adaptation. Don’t be afraid to push your limits when using HMB. 

Week 1-2: 

Your muscle levels of HMB will be increasing and you’ll start to notice that you aren’t quite as sore as you usually are after training. 

Week 3-4: 

This is when you’ll start to notice some performance improvements. You’ll feel fresher when training, feel more recovered and able to train at a higher intensity (which you should do)

Month 2 of regular training: You’ll be able to train at a higher intensity and more frequently with the body able to handle the volume. The progress you make will start to speed up, regardless of the training you do. If you’re measuring performance, this is when you’ll start to see impact. 

If you’re recovering from injury:

If you’re taking HMB to prevent muscle loss through injury or inactivity you’ll notice the impact of taking HMB in the return-to-sport process. You’ll have lost less power, strength and muscle mass, cutting your return time. 

Anecdotally, we find that many athletes report that they notice when they stop taking HMB. They report a noticeable increase in training induced soreness.

Ready to see what HMB can do for you?

Did you know?

HMB is one of the few supplement ingredients to get the thumbs up from the International Society of Sports Nutrition (ISSN)


The other ingredients to be approved are creatine monohydrate and beta-alanine.

The Research on HMB

HMB is now one of the most researched sports nutrition ingredients on the market. There is much variation in the athlete type (from novice to highly trained, weightlifter to distance runners and football players) to the duration of study used (weeks to several months). This research is summarised in a great review by the International Society of Sports Nutrition

It’s not all studies that show HMB to be effective however, and this is likely due to different study sizes, types of training, levels of control etc, and in some cases a fake HMB product being used!

In the majority however it has been shown to be both safe and effective in training athletes. Here is a summary of findings in the research:

  • The effective dosage is ~3g/day or 38mg/kg body weight per day if you wan to fine tune it. 
  • HMB is a likely more effective in untrained individuals, probably because you experience more muscle damage when you start out
  • HMB works and is safe to take in athletes of all ages and sexes
  • HMB reduces muscle soreness and damage
  • HMB improves strength, muscle mass, endurance and power
  • It works in weightlifters, cyclists, runners, rowers and various other sports
  • HMB is just as effective in its calcium form as it is in an alternative free acid form
  • HMB can be combined with creatine to further increase strength, power and muscle
  • HMB works to reduce muscle loss in aging and disease conditions
  • HMB likely works by altering muscle protein production via the mTOR pathway
  • HMB seems to be more effective if combined with vitamin D in the winter months
  • HMB can speed injury recovery time

HMB research is now more focused on it’s health benefits, especially in the aging and diseased populations

More research on HMB is being published each month. To search the latest articles click here.

HMB isn't a banned substance

HMB is classified as a dietary supplement and is NOT on the World Anti Doping Agency (WADA)'s list of banned substances, meaning it is OK to take if you are an athlete who is drug tested. This being said, you should always find out what your supplement providers do to protect you as an athlete if you are drug tested.

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